Lichen Planus (Clinical)

Epidemiology and Etiology

Epidemiology^[5,6,8]

• Lichen planus Lichen planus Lichen planus (LP) is an idiopathic, cell-mediated inflammatory skin disease. It is characterized by pruritic, flat-topped, papular, purple skin lesions commonly found on the flexural surfaces of the extremities. Other areas affected include genitalia, nails, scalp, and mucous membranes. Lichen Planus (LP) affects < 1% of the population in the United States.
• Can occur at any age, but most commonly found in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship 30–60 years of age
• Rare in children

Etiology^[1–3,5,14]

• Unknown
• Associated risk factors: 
  • Genetic predisposition: ↑ frequency of human leukocyte antigen Antigen Substances that are recognized by the immune system and induce an immune reaction. Vaccination B7 (HLA-B7), HLA-DR1, and HLA-DR10 in those affected 
  • Hepatitis C Hepatitis C Hepatitis C is an infection of the liver caused by the hepatitis C virus (HCV). The infection can be transmitted through infectious blood or body fluids and may be transmitted during childbirth or through IV drug use or sexual intercourse. Hepatitis C virus can cause both acute and chronic hepatitis, ranging from a mild to a serious, lifelong illness including liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis C Virus virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology infection
  • Drug exposure:
    • Angiotensin-converting enzyme (ACE) inhibitors 
    • Beta-blockers Beta-blockers Drugs that bind to but do not activate beta-adrenergic receptors thereby blocking the actions of beta-adrenergic agonists. Adrenergic beta-antagonists are used for treatment of hypertension, cardiac arrhythmias, angina pectoris, glaucoma, migraine headaches, and anxiety. Class 2 Antiarrhythmic Drugs (Beta Blockers)
    • Methyldopa
    • Quinidine Quinidine An optical isomer of quinine, extracted from the bark of the cinchona tree and similar plant species. This alkaloid dampens the excitability of cardiac and skeletal muscles by blocking sodium and potassium currents across cellular membranes. It prolongs cellular action potentials, and decreases automaticity. Quinidine also blocks muscarinic and alpha-adrenergic neurotransmission. Class 1 Antiarrhythmic Drugs (Sodium Channel Blockers)
    • Chloroquine Chloroquine The prototypical antimalarial agent with a mechanism that is not well understood. It has also been used to treat rheumatoid arthritis, systemic lupus erythematosus, and in the systemic therapy of amebic liver abscesses. Antimalarial Drugs 
    • Hydroxychloroquine Hydroxychloroquine A chemotherapeutic agent that acts against erythrocytic forms of malarial parasites. Hydroxychloroquine appears to concentrate in food vacuoles of affected protozoa. It inhibits plasmodial heme polymerase. Immunosuppressants
    • Thiazide Thiazide Heterocyclic compounds with sulfur and nitrogen in the ring. This term commonly refers to the benzothiadiazines that inhibit sodium-potassium-chloride symporters and are used as diuretics. Hyponatremia diuretics Diuretics Agents that promote the excretion of urine through their effects on kidney function. Heart Failure and Angina Medication
    • Gold salts
  • Primary biliary cirrhosis Biliary cirrhosis Fibrosis of the hepatic parenchyma due to obstruction of bile flow (cholestasis) in the intrahepatic or extrahepatic bile ducts. Primary biliary cholangitis involves the destruction of small intrahepatic bile ducts and decreased bile secretion. Secondary biliary cholangitis is produced by prolonged obstruction of large intrahepatic or extrahepatic bile ducts from a variety of causes. Cystic Fibrosis
  • Human herpesvirus type 7
  • Mercury Mercury A silver metallic element that exists as a liquid at room temperature. It has the atomic symbol Hg (from hydrargyrum, liquid silver), atomic number 80, and atomic weight 200. 59. Mercury is used in many industrial applications and its salts have been employed therapeutically as purgatives, antisyphilitics, disinfectants, and astringents. It can be absorbed through the skin and mucous membranes which leads to mercury poisoning. Because of its toxicity, the clinical use of mercury and mercurials is diminishing. Renal Tubular Acidosis (in dental amalgam)
  • Radiotherapy
• Psychogenic factors, such as anxiety Anxiety Feelings or emotions of dread, apprehension, and impending disaster but not disabling as with anxiety disorders. Generalized Anxiety Disorder, depression, and stress

Pathophysiology

• Proposed mechanism involves cell-mediated immunity Cell-mediated immunity Manifestations of the immune response which are mediated by antigen-sensitized T-lymphocytes via lymphokines or direct cytotoxicity. This takes place in the absence of circulating antibody or where antibody plays a subordinate role. Squamous Cell Carcinoma (SCC).^[1,5,8]
• Exposure to exogenous agent (drug, virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology, other risk factors) → alters epidermal self-antigens
• CD4+ and CD8+ (more predominant) lymphocytes Lymphocytes Lymphocytes are heterogeneous WBCs involved in immune response. Lymphocytes develop from the bone marrow, starting from hematopoietic stem cells (HSCs) and progressing to common lymphoid progenitors (CLPs). B and T lymphocytes and natural killer (NK) cells arise from the lineage. Lymphocytes: Histology are recruited to dermal-epidermal junction → lead a T-cell–mediated attack → apoptosis Apoptosis A regulated cell death mechanism characterized by distinctive morphologic changes in the nucleus and cytoplasm, including the endonucleolytic cleavage of genomic DNA, at regularly spaced, internucleosomal sites, I.e., DNA fragmentation. It is genetically-programmed and serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth. Ischemic Cell Damage of keratinocytes Keratinocytes Epidermal cells which synthesize keratin and undergo characteristic changes as they move upward from the basal layers of the epidermis to the cornified (horny) layer of the skin. Successive stages of differentiation of the keratinocytes forming the epidermal layers are basal cell, spinous or prickle cell, and the granular cell. Skin: Structure and Functions 
• Basal layer is injured → release melanin Melanin Insoluble polymers of tyrosine derivatives found in and causing darkness in skin (skin pigmentation), hair, and feathers providing protection against sunburn induced by sunlight. Carotenes contribute yellow and red coloration. Seborrheic Keratosis into dermis Dermis A layer of vascularized connective tissue underneath the epidermis. The surface of the dermis contains innervated papillae. Embedded in or beneath the dermis are sweat glands; hair follicles; and sebaceous glands. Skin: Structure and Functions → hyperpigmentation Hyperpigmentation Excessive pigmentation of the skin, usually as a result of increased epidermal or dermal melanin pigmentation, hypermelanosis. Hyperpigmentation can be localized or generalized. The condition may arise from exposure to light, chemicals or other substances, or from a primary metabolic imbalance. Malassezia Fungi
• Interaction of T lymphocytes T lymphocytes Lymphocytes responsible for cell-mediated immunity. Two types have been identified – cytotoxic (t-lymphocytes, cytotoxic) and helper T-lymphocytes (t-lymphocytes, helper-inducer). They are formed when lymphocytes circulate through the thymus gland and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen. T cells: Types and Functions and basal keratinocytes Keratinocytes Epidermal cells which synthesize keratin and undergo characteristic changes as they move upward from the basal layers of the epidermis to the cornified (horny) layer of the skin. Successive stages of differentiation of the keratinocytes forming the epidermal layers are basal cell, spinous or prickle cell, and the granular cell. Skin: Structure and Functions enhanced by:
  • Intercellular adhesion Adhesion The process whereby platelets adhere to something other than platelets, e.g., collagen; basement membrane; microfibrils; or other ‘foreign’ surfaces. Coagulation Studies molecule-1 (ICAM-1) upregulation by basal keratinocytes Keratinocytes Epidermal cells which synthesize keratin and undergo characteristic changes as they move upward from the basal layers of the epidermis to the cornified (horny) layer of the skin. Successive stages of differentiation of the keratinocytes forming the epidermal layers are basal cell, spinous or prickle cell, and the granular cell. Skin: Structure and Functions 
  • Other cytokines Cytokines Non-antibody proteins secreted by inflammatory leukocytes and some non-leukocytic cells, that act as intercellular mediators. They differ from classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. They generally act locally in a paracrine or autocrine rather than endocrine manner. Adaptive Immune Response: interferon ( IFN IFN Interferon (IFN) is a cytokine with antiviral properties (it interferes with viral infections) and various roles in immunoregulation. The different types are type I IFN (IFN-ɑ and IFN-β), type II IFN (IFN-ɣ), and type III IFN (IFN-ƛ). Interferons)-gamma, tumor Tumor Inflammation necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage factor ( TNF TNF Tumor necrosis factor (TNF) is a major cytokine, released primarily by macrophages in response to stimuli. The presence of microbial products and dead cells and injury are among the stimulating factors. This protein belongs to the TNF superfamily, a group of ligands and receptors performing functions in inflammatory response, morphogenesis, and cell proliferation. Tumor Necrosis Factor (TNF))-alpha, interleukin (IL)-1 alpha, IL-6, and IL-8

Clinical Presentation

Cutaneous LP^[5,6]

• Clinical features:
  • Primary lesions can be characterized by the 6 Ps PS Invasive Mechanical Ventilation:
    • Polygonal
    • Purple (violaceous)
    • Pruritic (often severe)
    • Planar Papules (flat-topped)
    • May coalesce into larger Plaques
  • Wickham’s striae: lace-like white lines/dots, can be seen on the surface of the lesions
  • Koebner phenomenon Koebner Phenomenon Lichen Planus:
    • Development of lesions in previously healthy sites 
    • Due to trauma from scratching
  • Hyperpigmentation Hyperpigmentation Excessive pigmentation of the skin, usually as a result of increased epidermal or dermal melanin pigmentation, hypermelanosis. Hyperpigmentation can be localized or generalized. The condition may arise from exposure to light, chemicals or other substances, or from a primary metabolic imbalance. Malassezia Fungi occurs with healed lesions.
  • May be painful depending on location
• Distribution and location:
  • Symmetric and bilateral
  • Most commonly found on flexural surfaces of extremities (ankles and wrists) 
• Clinical course:
  • Most resolve within 1–2 years
  • May leave permanent hyperpigmented macules after active disease is cleared

Cutaneous variants by morphology^[5,6,8]

• Hypertrophic:
  • Lichen planus Lichen planus Lichen planus (LP) is an idiopathic, cell-mediated inflammatory skin disease. It is characterized by pruritic, flat-topped, papular, purple skin lesions commonly found on the flexural surfaces of the extremities. Other areas affected include genitalia, nails, scalp, and mucous membranes. Lichen Planus verrucosus
  • Most pruritic form; associated with residual scarring Scarring Inflammation
  • Affects the anterior distal lower extremities
• Annular Annular Dermatologic Examination:
  • Plaques with central clearing
• Bullous:
  • Vesicles Vesicles Female Genitourinary Examination or bullae Bullae Erythema Multiforme develop within existing lesions.
  • Legs usually affected
• Actinic:
  • Plaques develop in sun-exposed areas.
  • Seen in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship of Middle Eastern descent
• Pigmentosus:
  • Gray-brown or dark-brown patches Patches Vitiligo 
  • Located in sun-exposed areas
• Inverse:
  • Plaques develop in uncommon sites (axillae, inguinal creases, inframammary area, limb flexures).
• Atrophic:
  • Plaques are well-demarcated pale or violaceous papules with superficial atrophy Atrophy Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes. Cellular Adaptation.
• Note: Additional subtypes related to lesion distribution exist (e.g., blaschkoid LP, zosteriform LP).^[5]

Oral LP^[5–7,13]

• Clinical features:
  • Can occur independently or with cutaneous LP
  • Can present as:
    • Wickham’s striae or reticular form (lacy, web-like white threads)
    • Atrophic lesions
    • Bullous lesions
    • Painful erosions Erosions Corneal Abrasions, Erosion, and Ulcers or ulcers (erosive mucosal lichen planus Lichen planus Lichen planus (LP) is an idiopathic, cell-mediated inflammatory skin disease. It is characterized by pruritic, flat-topped, papular, purple skin lesions commonly found on the flexural surfaces of the extremities. Other areas affected include genitalia, nails, scalp, and mucous membranes. Lichen Planus) that can lead to secondary Candida Candida Candida is a genus of dimorphic, opportunistic fungi. Candida albicans is part of the normal human flora and is the most common cause of candidiasis. The clinical presentation varies and can include localized mucocutaneous infections (e.g., oropharyngeal, esophageal, intertriginous, and vulvovaginal candidiasis) and invasive disease (e.g., candidemia, intraabdominal abscess, pericarditis, and meningitis). Candida/Candidiasis infection and/or loss of appetite due to pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
• Location:
  • Most common in buccal mucosa Buccal mucosa Oral Cancer
  • Also affects alveolar mucosa and tongue Tongue The tongue, on the other hand, is a complex muscular structure that permits tasting and facilitates the process of mastication and communication. The blood supply of the tongue originates from the external carotid artery, and the innervation is through cranial nerves. Lips and Tongue: Anatomy
• Clinical course: a chronic form of LP
• Mucosal and paramucosal lesions, especially at oral and vulvar sites (but not cutaneous lesions) have an increased risk of squamous cell carcinoma Squamous cell carcinoma Cutaneous squamous cell carcinoma (cSCC) is caused by malignant proliferation of atypical keratinocytes. This condition is the 2nd most common skin malignancy and usually affects sun-exposed areas of fair-skinned patients. The cancer presents as a firm, erythematous, keratotic plaque or papule. Squamous Cell Carcinoma (SCC).

Genital LP^[5–7]

• More common in men; lesions are typically on the glans penis Glans Penis Penis: Anatomy.
• In women, vulva Vulva The vulva is the external genitalia of the female and includes the mons pubis, labia majora, labia minora, clitoris, vestibule, vestibular bulb, and greater vestibular glands. Vagina, Vulva, and Pelvic Floor: Anatomy and vagina Vagina The vagina is the female genital canal, extending from the vulva externally to the cervix uteri internally. The structures have sexual, reproductive, and urinary functions and a rich blood supply, mainly arising from the internal iliac artery. Vagina, Vulva, and Pelvic Floor: Anatomy are affected.
  • Associated with pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema) and dyspareunia Dyspareunia Recurrent genital pain occurring during, before, or after sexual intercourse in either the male or the female. Primary Ovarian Insufficiency
  • Erosive lesions can be complicated by urethral stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS).
  • Increased risk of squamous cell carcinoma Squamous cell carcinoma Cutaneous squamous cell carcinoma (cSCC) is caused by malignant proliferation of atypical keratinocytes. This condition is the 2nd most common skin malignancy and usually affects sun-exposed areas of fair-skinned patients. The cancer presents as a firm, erythematous, keratotic plaque or papule. Squamous Cell Carcinoma (SCC)
• Clinical course: chronic or persistent

Other forms of LP^[5–7]

• Nail:
  • Can be minor dystrophy to total nail loss
  • Dorsal pterygium (raised wedge-shaped deformity Deformity Examination of the Upper Limbs of nailbed): most specific LP nail abnormality
• Lichen planopilaris Lichen Planopilaris Lichen Planus:
  • LP of the scalp that leads to keratotic follicular papules
  • Affects women more than men
  • Can progress to scarring Scarring Inflammation alopecia Alopecia Alopecia is the loss of hair in areas anywhere on the body where hair normally grows. Alopecia may be defined as scarring or non-scarring, localized or diffuse, congenital or acquired, reversible or permanent, or confined to the scalp or universal; however, alopecia is usually classified using the 1st 3 factors. Alopecia if left untreated
• Esophageal:
  • Can be asymptomatic or present with dysphagia Dysphagia Dysphagia is the subjective sensation of difficulty swallowing. Symptoms can range from a complete inability to swallow, to the sensation of solids or liquids becoming “stuck.” Dysphagia is classified as either oropharyngeal or esophageal, with esophageal dysphagia having 2 sub-types: functional and mechanical. Dysphagia or odynophagia Odynophagia Epiglottitis
  • Endoscopic findings: pseudomembranes Pseudomembranes Raised yellow or off-white plaques up to 2 cm in diameter that form as a result of mucosal ulceration Pseudomembranous Colitis, friable and inflamed mucosa, submucosal papules, lacy-white plaques, erosions Erosions Corneal Abrasions, Erosion, and Ulcers
  • Can lead to esophageal stricture Stricture Primary Sclerosing Cholangitis
• Otic:
  • Affects external auditory canals and tympanic membranes
  • Presents with erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion, pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema), and induration Induration Dermatologic Examination; but can cause persistent otorrhea Otorrhea Otitis Externa and hearing loss Hearing loss Hearing loss, also known as hearing impairment, is any degree of impairment in the ability to apprehend sound as determined by audiometry to be below normal hearing thresholds. Clinical presentation may occur at birth or as a gradual loss of hearing with age, including a short-term or sudden loss at any point. Hearing Loss

Diagnosis

Definitive diagnosis is made based on typical morphologic lesions on exam, in combination with associated histopathologic findings at the affected site.^[8,9]

History and clinical findings^[5,8]

• Review of medical history, medications, and risk factors (e.g., hepatitis C Hepatitis C Hepatitis C is an infection of the liver caused by the hepatitis C virus (HCV). The infection can be transmitted through infectious blood or body fluids and may be transmitted during childbirth or through IV drug use or sexual intercourse. Hepatitis C virus can cause both acute and chronic hepatitis, ranging from a mild to a serious, lifelong illness including liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis C Virus)
• Physical examination of entire cutaneous surface (including the scalp, oral cavity, and external genitalia)

Mucocutaneous biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma^[5,6,8]

• Deep shave or punch biopsy Punch Biopsy Actinic Keratosis of the most prominent lesion^[8,9]
• Histopathological findings include:^[8,9]
  • Hyperkeratosis Hyperkeratosis Ichthyosis Vulgaris ( hyperplasia Hyperplasia An increase in the number of cells in a tissue or organ without tumor formation. It differs from hypertrophy, which is an increase in bulk without an increase in the number of cells. Cellular Adaptation of the stratum corneum Stratum corneum Skin: Structure and Functions)
  • Civatte bodies (anucleate, necrotic hypereosinophilic keratinocytes Keratinocytes Epidermal cells which synthesize keratin and undergo characteristic changes as they move upward from the basal layers of the epidermis to the cornified (horny) layer of the skin. Successive stages of differentiation of the keratinocytes forming the epidermal layers are basal cell, spinous or prickle cell, and the granular cell. Skin: Structure and Functions) in the lower epidermis Epidermis The external, nonvascular layer of the skin. It is made up, from within outward, of five layers of epithelium: (1) basal layer (stratum basale epidermidis); (2) spinous layer (stratum spinosum epidermidis); (3) granular layer (stratum granulosum epidermidis); (4) clear layer (stratum lucidum epidermidis); and (5) horny layer (stratum corneum epidermidis). Skin: Structure and Functions
  • Wedge-shaped hypergranulosis ( hyperplasia Hyperplasia An increase in the number of cells in a tissue or organ without tumor formation. It differs from hypertrophy, which is an increase in bulk without an increase in the number of cells. Cellular Adaptation of the stratum granulosum Stratum granulosum Skin: Structure and Functions)
  • “Saw-tooth” rete ridges Rete Ridges Lentigo Maligna 
  • Vacuolar alteration of basal layer of epidermis Epidermis The external, nonvascular layer of the skin. It is made up, from within outward, of five layers of epithelium: (1) basal layer (stratum basale epidermidis); (2) spinous layer (stratum spinosum epidermidis); (3) granular layer (stratum granulosum epidermidis); (4) clear layer (stratum lucidum epidermidis); and (5) horny layer (stratum corneum epidermidis). Skin: Structure and Functions
  • Band-like Band-Like Tension Headaches lymphocytic infiltrate at the dermal–epidermal junction Dermal–Epidermal Junction Bullous Pemphigoid and Pemphigus Vulgaris

Other tests^[5,8]

• Direct immunofluorescence:
  • May show:
    • Deposits of:
      • Immunoglobulins Immunoglobulins Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions (especially IgM IgM A class of immunoglobulin bearing mu chains (immunoglobulin mu-chains). Igm can fix complement. The name comes from its high molecular weight and originally being called a macroglobulin. Immunoglobulins: Types and Functions)
      • Complement
      • Fibrinogen Fibrinogen Plasma glycoprotein clotted by thrombin, composed of a dimer of three non-identical pairs of polypeptide chains (alpha, beta, gamma) held together by disulfide bonds. Fibrinogen clotting is a sol-gel change involving complex molecular arrangements: whereas fibrinogen is cleaved by thrombin to form polypeptides a and b, the proteolytic action of other enzymes yields different fibrinogen degradation products. Hemostasis
    • Apoptotic keratinocytes Keratinocytes Epidermal cells which synthesize keratin and undergo characteristic changes as they move upward from the basal layers of the epidermis to the cornified (horny) layer of the skin. Successive stages of differentiation of the keratinocytes forming the epidermal layers are basal cell, spinous or prickle cell, and the granular cell. Skin: Structure and Functions
  • Helpful in distinguishing erosive LP from pemphigus vulgaris Pemphigus vulgaris Bullous pemphigoid and pemphigus vulgaris are two different blistering autoimmune diseases. In pemphigus vulgaris, autoantibodies attack the desmosomal proteins, which connect the keratinocytes to one another. This attack results in a more severe, potentially fatal condition with fragile, flaccid blisters, usually with significant mucosal involvement. Bullous Pemphigoid and Pemphigus Vulgaris
• Dermoscopy Dermoscopy A noninvasive technique that enables direct microscopic examination of the surface and architecture of the skin. Seborrheic Keratosis may show:
  • White crossing lines (Wickham sign)
  • Dull, red background
  • Peripheral vessels
• Laboratory tests: screen for hepatitis C Hepatitis C Hepatitis C is an infection of the liver caused by the hepatitis C virus (HCV). The infection can be transmitted through infectious blood or body fluids and may be transmitted during childbirth or through IV drug use or sexual intercourse. Hepatitis C virus can cause both acute and chronic hepatitis, ranging from a mild to a serious, lifelong illness including liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis C Virus in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with risk factors

Management

Management may vary based on location. The following recommendations are based on US, UK, and European literature and guidelines. Specialist consultation (e.g., dermatology) is recommended to help guide therapy.

Cutaneous LP

Classical cutaneous LP may resolve spontaneously (6 months to 2 years). However, the following treatments may be used to alleviate symptoms and speed up resolution. There is some variation in 1st– and 2nd–line treatments between European and US literature.^[6,8]

Supportive care:^[6,8]

• Oral antihistamines Antihistamines Antihistamines are drugs that target histamine receptors, particularly H1 and H2 receptors. H1 antagonists are competitive and reversible inhibitors of H1 receptors. First-generation antihistamines cross the blood-brain barrier and can cause sedation. Antihistamines
• Topical antipruritics, as needed ( menthol Menthol A monoterpene cyclohexanol produced from mint oils. Pityriasis Rosea, camphor, doxepin Doxepin A dibenzoxepin tricyclic compound. It displays a range of pharmacological actions including maintaining adrenergic innervation. Its mechanism of action is not fully understood, but it appears to block reuptake of monoaminergic neurotransmitters into presynaptic terminals. It also possesses anticholinergic activity and modulates antagonism of histamine h(1)- and h(2)-receptors. Tricyclic Antidepressants topical local anesthetics Anesthetics Agents that are capable of inducing a total or partial loss of sensation, especially tactile sensation and pain. They may act to induce general anesthesia, in which an unconscious state is achieved, or may act locally to induce numbness or lack of sensation at a targeted site. Anesthesiology: History and Basic Concepts) 

1st–line treatment:^[5,8,10]

• Topical steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors (superpotent and potent):
  • Triamcinolone Triamcinolone A glucocorticoid given, as the free alcohol or in esterified form, orally, intramuscularly, by local injection, by inhalation, or applied topically in the management of various disorders in which corticosteroids are indicated. Glucocorticoids acetonide
  • Clobetasol Clobetasol A derivative of prednisolone with high glucocorticoid activity and low mineralocorticoid activity. Absorbed through the skin faster than fluocinonide, it is used topically in treatment of psoriasis but may cause marked adrenocortical suppression. Glucocorticoids propionate
  • Fluocinolone acetonide
  • Betamethasone Betamethasone A glucocorticoid given orally, parenterally, by local injection, by inhalation, or applied topically in the management of various disorders in which corticosteroids are indicated. Its lack of mineralocorticoid properties makes betamethasone particularly suitable for treating cerebral edema and congenital adrenal hyperplasia. Glucocorticoids dipropionate
• Intralesional injections:
  • May be helpful for:
    • Discrete lesions
    • Hypertrophic lesions
  • Option: triamcinolone Triamcinolone A glucocorticoid given, as the free alcohol or in esterified form, orally, intramuscularly, by local injection, by inhalation, or applied topically in the management of various disorders in which corticosteroids are indicated. Glucocorticoids

2nd–line treatment:^[5,6,8,10]

• For lesions unresponsive to 1st-line or for severe LP
• Can be used individually or in combination
• Systemic corticosteroids Corticosteroids Chorioretinitis:
  • Oral: prednisone Prednisone A synthetic anti-inflammatory glucocorticoid derived from cortisone. It is biologically inert and converted to prednisolone in the liver. Immunosuppressants
  • IM: triamcinolone Triamcinolone A glucocorticoid given, as the free alcohol or in esterified form, orally, intramuscularly, by local injection, by inhalation, or applied topically in the management of various disorders in which corticosteroids are indicated. Glucocorticoids 
• Oral retinoids Retinoids Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of carotenoids found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products. Fat-soluble Vitamins and their Deficiencies:
  • Options:
    • Acitretin
    • Isotretinoin
  • Teratogenic
• Phototherapy Phototherapy Treatment of disease by exposure to light, especially by variously concentrated light rays or specific wavelengths. Hyperbilirubinemia of the Newborn:
  • Options:
    • Broad or narrowband ultraviolet B (UVB)
    • Psoralen Psoralen Melanoma plus ultraviolet A (UVA)
  • UVB is preferred over UVA (potential increased risk of skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions cancer with long-term use)

Other potential treatments:^[5,8,10] 

• Vitamin derivatives:
  • Topical calcipotriol ( vitamin D Vitamin D A vitamin that includes both cholecalciferols and ergocalciferols, which have the common effect of preventing or curing rickets in animals. It can also be viewed as a hormone since it can be formed in skin by action of ultraviolet rays upon the precursors, 7-dehydrocholesterol and ergosterol, and acts on vitamin D receptors to regulate calcium in opposition to parathyroid hormone. Fat-soluble Vitamins and their Deficiencies)
  • Alitretinoin ( vitamin A Vitamin A Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of carotenoids found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products. Fat-soluble Vitamins and their Deficiencies)
• Antibiotics:
  • Metronidazole Metronidazole A nitroimidazole used to treat amebiasis; vaginitis; trichomonas infections; giardiasis; anaerobic bacteria; and treponemal infections. Pyogenic Liver Abscess
  • Trimethoprim Trimethoprim The sulfonamides are a class of antimicrobial drugs inhibiting folic acid synthesize in pathogens. The prototypical drug in the class is sulfamethoxazole. Although not technically sulfonamides, trimethoprim, dapsone, and pyrimethamine are also important antimicrobial agents inhibiting folic acid synthesis. The agents are often combined with sulfonamides, resulting in a synergistic effect. Sulfonamides and Trimethoprim– sulfamethoxazole Sulfamethoxazole A bacteriostatic antibacterial agent that interferes with folic acid synthesis in susceptible bacteria. Its broad spectrum of activity has been limited by the development of resistance. Sulfonamides and Trimethoprim
  • Tetracycline Tetracycline A naphthacene antibiotic that inhibits amino Acyl tRNA binding during protein synthesis. Drug-Induced Liver Injury 
  • Doxycycline
• Antimalarial: hydroxychloroquine Hydroxychloroquine A chemotherapeutic agent that acts against erythrocytic forms of malarial parasites. Hydroxychloroquine appears to concentrate in food vacuoles of affected protozoa. It inhibits plasmodial heme polymerase. Immunosuppressants
• Antifungals:
  • Itraconazole Itraconazole A triazole antifungal agent that inhibits cytochrome p-450-dependent enzymes required for ergosterol synthesis. Azoles 
  • Terbinafine Terbinafine In addition to the 3 other major classes of antifungal agents (azoles, polyenes, and echinocandins), several other clinically important antifungal agents are used, including flucytosine, griseofulvin, and terbinafine. Terbinafine acts within the stratum corneum of the skin and are used to treat dermatophyte infections of the skin, hair, and nails. Flucytosine, Griseofulvin, and Terbinafine 
  • Griseofulvin Griseofulvin In addition to the 3 other major classes of antifungal agents (azoles, polyenes, and echinocandins), several other clinically important antifungal agents are used, including flucytosine, griseofulvin, and terbinafine. Griseofulvin acts within the stratum corneum of the skin and are used to treat dermatophyte infections of the skin, hair, and nails. Flucytosine, Griseofulvin, and Terbinafine 
• Immunomodulators/ immunosuppressants Immunosuppressants Immunosuppressants are a class of drugs widely used in the management of autoimmune conditions and organ transplant rejection. The general effect is dampening of the immune response. Immunosuppressants:
  • Mycophenolate Mycophenolate Immunosuppressants mofetil
  • Azathioprine Azathioprine An immunosuppressive agent used in combination with cyclophosphamide and hydroxychloroquine in the treatment of rheumatoid arthritis. According to the fourth annual report on carcinogens, this substance has been listed as a known carcinogen. Immunosuppressants 
  • Methotrexate Methotrexate An antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of tetrahydrofolate dehydrogenase and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA. Antimetabolite Chemotherapy
  • Cyclophosphamide Cyclophosphamide Precursor of an alkylating nitrogen mustard antineoplastic and immunosuppressive agent that must be activated in the liver to form the active aldophosphamide. It has been used in the treatment of lymphoma and leukemia. Its side effect, alopecia, has been used for defleecing sheep. Cyclophosphamide may also cause sterility, birth defects, mutations, and cancer. Immunosuppressants
  • Thalidomide Thalidomide A piperidinyl isoindole originally introduced as a non-barbiturate hypnotic, but withdrawn from the market due to teratogenic effects. It has been reintroduced and used for a number of immunological and inflammatory disorders. Thalidomide displays immunosuppressive and anti-angiogenic activity. It inhibits release of tumor necrosis factor-alpha from monocytes, and modulates other cytokine action. Immunosuppressants
  • Adalimumab Adalimumab A humanized monoclonal antibody that binds specifically to tnf-alpha and blocks its interaction with endogenous tnf receptors to modulate inflammation. It is used in the treatment of rheumatoid arthritis; psoriatic arthritis; Crohn’s disease and ulcerative colitis. Disease-Modifying Antirheumatic Drugs (DMARDs)
  • Interferon-alfa 2b (HCV-induced)
  • Apremilast Apremilast Phosphodiesterase Inhibitors
  • Ustekinumab Ustekinumab A humanized monoclonal antibody that binds to il-12 and il-23 and is used as a dermatologic agent in the treatment of patients with plaque psoriasis who have not responded to other therapies. Immunosuppressants
• Miscellaneous:
  • Low-molecular-weight heparin 
  • Photodynamic therapy Photodynamic Therapy Actinic Keratosis
  • Extracorporeal photochemotherapy
  • Nd-YAG laser, low-dose 308-nm excimer laser

Oral LP 

Similar to cutaneous LP, recommendations for 1st and 2nd-line therapies vary depending on the literature source.

1st-line treatment:^[5,6,8,10] 

• Topical corticosteroids Corticosteroids Chorioretinitis:
  • Betamethasone Betamethasone A glucocorticoid given orally, parenterally, by local injection, by inhalation, or applied topically in the management of various disorders in which corticosteroids are indicated. Its lack of mineralocorticoid properties makes betamethasone particularly suitable for treating cerebral edema and congenital adrenal hyperplasia. Glucocorticoids valerate
  • Fluocinonide Fluocinonide Glucocorticoids
  • Clobetasol Clobetasol A derivative of prednisolone with high glucocorticoid activity and low mineralocorticoid activity. Absorbed through the skin faster than fluocinonide, it is used topically in treatment of psoriasis but may cause marked adrenocortical suppression. Glucocorticoids propionate 0.05%
  • Triamcinolone Triamcinolone A glucocorticoid given, as the free alcohol or in esterified form, orally, intramuscularly, by local injection, by inhalation, or applied topically in the management of various disorders in which corticosteroids are indicated. Glucocorticoids
  • Fluticasone Fluticasone A steroid with glucocorticoid receptor activity that is used to manage the symptoms of asthma; allergic rhinitis, and atopic dermatitis. Glucocorticoids
• Systemic corticosteroids Corticosteroids Chorioretinitis:
  • Can be used alone or in combination with topical therapy
  • Used for severe, widespread, or erosive lesions
  • Options:
    • Prednisone Prednisone A synthetic anti-inflammatory glucocorticoid derived from cortisone. It is biologically inert and converted to prednisolone in the liver. Immunosuppressants
    • Methylprednisolone Methylprednisolone A prednisolone derivative with similar anti-inflammatory action. Immunosuppressants

2nd-line treatment (for severe or refractory LP):^[5,8,10] 

• Retinoids Retinoids Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of carotenoids found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products. Fat-soluble Vitamins and their Deficiencies:
  • Acitretin
  • Isotretinoin
• Hydroxychloroquine Hydroxychloroquine A chemotherapeutic agent that acts against erythrocytic forms of malarial parasites. Hydroxychloroquine appears to concentrate in food vacuoles of affected protozoa. It inhibits plasmodial heme polymerase. Immunosuppressants
• Topical calcineurin inhibitors Calcineurin Inhibitors Compounds that inhibit or block the phosphatase activity of calcineurin. Immunosuppressants:
  • Not recommended by the US FDA, but European guidelines do support its use
  • Options:
    • Tacrolimus Tacrolimus A macrolide isolated from the culture broth of a strain of streptomyces tsukubaensis that has strong immunosuppressive activity in vivo and prevents the activation of T-lymphocytes in response to antigenic or mitogenic stimulation in vitro. Immunosuppressants
    • Pimecrolimus Pimecrolimus Immunosuppressants

Other potential options:^[5,8]

• Sulfasalazine Sulfasalazine A drug that is used in the management of inflammatory bowel diseases. Its activity is generally considered to lie in its metabolic breakdown product, 5-aminosalicylic acid released in the colon. Sulfonamides and Trimethoprim
• Azathioprine Azathioprine An immunosuppressive agent used in combination with cyclophosphamide and hydroxychloroquine in the treatment of rheumatoid arthritis. According to the fourth annual report on carcinogens, this substance has been listed as a known carcinogen. Immunosuppressants
• Cyclosporine Cyclosporine A cyclic undecapeptide from an extract of soil fungi. It is a powerful immunosupressant with a specific action on T-lymphocytes. It is used for the prophylaxis of graft rejection in organ and tissue transplantation. Immunosuppressants
• Methotrexate Methotrexate An antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of tetrahydrofolate dehydrogenase and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA. Antimetabolite Chemotherapy
• Mycophenolate Mycophenolate Immunosuppressants mofetil 
• TNF-a inhibitors (alefacept, adalimumab Adalimumab A humanized monoclonal antibody that binds specifically to tnf-alpha and blocks its interaction with endogenous tnf receptors to modulate inflammation. It is used in the treatment of rheumatoid arthritis; psoriatic arthritis; Crohn’s disease and ulcerative colitis. Disease-Modifying Antirheumatic Drugs (DMARDs), etanercept Etanercept A recombinant version of soluble human tnf receptor fused to an IgG Fc fragment that binds specifically to tumor necrosis factor and inhibits its binding with endogenous tnf receptors. It prevents the inflammatory effect of tnf and is used to treat rheumatoid arthritis; psoriatic arthritis and ankylosing spondylitis. Immunosuppressants)

Genital LP

Disease course can vary, with papulosquamous genital LP being self-limited. However, vulvovaginal LP is typically difficult to control. Additionally, erosive lesions can lead to scarring Scarring Inflammation.

Symptomatic treatment:^[8]

• Topical anesthetics Anesthetics Agents that are capable of inducing a total or partial loss of sensation, especially tactile sensation and pain. They may act to induce general anesthesia, in which an unconscious state is achieved, or may act locally to induce numbness or lack of sensation at a targeted site. Anesthesiology: History and Basic Concepts
• Sedating antihistamines Antihistamines Antihistamines are drugs that target histamine receptors, particularly H1 and H2 receptors. H1 antagonists are competitive and reversible inhibitors of H1 receptors. First-generation antihistamines cross the blood-brain barrier and can cause sedation. Antihistamines
• Low-dose tricyclic antidepressants Tricyclic antidepressants Tricyclic antidepressants (TCAs) are a class of medications used in the management of mood disorders, primarily depression. These agents, named after their 3-ring chemical structure, act via reuptake inhibition of neurotransmitters (particularly norepinephrine and serotonin) in the brain. Tricyclic Antidepressants
• Anticonvulsants

1st line treatment:^{[5,8,10–12,15]}

• High-potency topical corticosteroids Corticosteroids Chorioretinitis:
  • Clobetasol Clobetasol A derivative of prednisolone with high glucocorticoid activity and low mineralocorticoid activity. Absorbed through the skin faster than fluocinonide, it is used topically in treatment of psoriasis but may cause marked adrenocortical suppression. Glucocorticoids propionate 0.05%
  • Betamethasone Betamethasone A glucocorticoid given orally, parenterally, by local injection, by inhalation, or applied topically in the management of various disorders in which corticosteroids are indicated. Its lack of mineralocorticoid properties makes betamethasone particularly suitable for treating cerebral edema and congenital adrenal hyperplasia. Glucocorticoids dipropionate 0.05%
  • Fluocinonide Fluocinonide Glucocorticoids 0.05%
  • Hydrocortisone Hydrocortisone The main glucocorticoid secreted by the adrenal cortex. Its synthetic counterpart is used, either as an injection or topically, in the treatment of inflammation, allergy, collagen diseases, asthma, adrenocortical deficiency, shock, and some neoplastic conditions. Immunosuppressants 25 mg rectal suppository, inserted in the vagina Vagina The vagina is the female genital canal, extending from the vulva externally to the cervix uteri internally. The structures have sexual, reproductive, and urinary functions and a rich blood supply, mainly arising from the internal iliac artery. Vagina, Vulva, and Pelvic Floor: Anatomy, 1–2 times daily
• Wean to lower-potency or frequency application of corticosteroids Corticosteroids Chorioretinitis when possible

2nd-line treatment:^[8,10,11,12]

• Topical calcineurin inhibitors Calcineurin Inhibitors Compounds that inhibit or block the phosphatase activity of calcineurin. Immunosuppressants:
  • May be considered in LP recalcitrant to topical steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors
  • Options:
    • Tacrolimus Tacrolimus A macrolide isolated from the culture broth of a strain of streptomyces tsukubaensis that has strong immunosuppressive activity in vivo and prevents the activation of T-lymphocytes in response to antigenic or mitogenic stimulation in vitro. Immunosuppressants 0.1% ointment
    • Pimecrolimus Pimecrolimus Immunosuppressants 1% cream

Other potential options:^{[5,8,11,12,15]}

• Oral corticosteroids Corticosteroids Chorioretinitis:
  • High-dose preferred for severe, recalcitrant disease.
  • Taper gradually
• Other immunomodulators ( mycophenolate Mycophenolate Immunosuppressants mofetil, hydroxychloroquine Hydroxychloroquine A chemotherapeutic agent that acts against erythrocytic forms of malarial parasites. Hydroxychloroquine appears to concentrate in food vacuoles of affected protozoa. It inhibits plasmodial heme polymerase. Immunosuppressants, and methotrexate Methotrexate An antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of tetrahydrofolate dehydrogenase and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA. Antimetabolite Chemotherapy have some use in severe flares)
• Acitretin may be helpful in hypertrophic disease.
• Surgery:
  • May be necessary to restore sexual function (vulval and vaginal adhesions)
  • Contraindicated in active disease

Nail LP

Nail LP can be difficult to treat, and the goal is to limit Limit A value (e.g., pressure or time) that should not be exceeded and which is specified by the operator to protect the lung Invasive Mechanical Ventilation scarring Scarring Inflammation. Relapse Relapse Relapsing Fever is common.

1st line treatment:^[5,8,10,16]

• Intralesional corticosteroids Intralesional Corticosteroids Hypertrophic and Keloid Scars: triamcinolone Triamcinolone A glucocorticoid given, as the free alcohol or in esterified form, orally, intramuscularly, by local injection, by inhalation, or applied topically in the management of various disorders in which corticosteroids are indicated. Glucocorticoids
  • Preferred by some groups^[16]
  • Painful
• Topical steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors (super potent and potent):
  • Limited drug penetration Penetration X-rays
  • Not recommended in the US^[16]

2nd-line treatment:^[8,10,16]

• Systemic corticosteroids Corticosteroids Chorioretinitis:
  • Oral or IM
  • May also be used as an adjunct to 1st-line therapy
• Cyclosporine Cyclosporine A cyclic undecapeptide from an extract of soil fungi. It is a powerful immunosupressant with a specific action on T-lymphocytes. It is used for the prophylaxis of graft rejection in organ and tissue transplantation. Immunosuppressants
• Azathioprine Azathioprine An immunosuppressive agent used in combination with cyclophosphamide and hydroxychloroquine in the treatment of rheumatoid arthritis. According to the fourth annual report on carcinogens, this substance has been listed as a known carcinogen. Immunosuppressants

Lichen planopilaris Lichen Planopilaris Lichen Planus (scalp)

Management of lichen planopilaris Lichen Planopilaris Lichen Planus can be difficult. 

1st-line treatment:^[5,8,10]

• Ultrapotent, potent, or mild topical corticosteroids Corticosteroids Chorioretinitis
• Intralesional corticosteroids Intralesional Corticosteroids Hypertrophic and Keloid Scars: triamcinolone Triamcinolone A glucocorticoid given, as the free alcohol or in esterified form, orally, intramuscularly, by local injection, by inhalation, or applied topically in the management of various disorders in which corticosteroids are indicated. Glucocorticoids

2nd-line treatment:^[5,8,10]

• Systemic corticosteroids Corticosteroids Chorioretinitis for:
  • Severe disease
  • Rapidly progressive disease
  • Disease leading to scarring Scarring Inflammation
• Oral retinoids Retinoids Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of carotenoids found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products. Fat-soluble Vitamins and their Deficiencies: may be particularly helpful in LP with perifollicular hyperkeratosis Hyperkeratosis Ichthyosis Vulgaris

Other potential treatments:^[8,10]

• Tetracyclines Tetracyclines Tetracyclines are a class of broad-spectrum antibiotics indicated for a wide variety of bacterial infections. These medications bind the 30S ribosomal subunit to inhibit protein synthesis of bacteria. Tetracyclines cover gram-positive and gram-negative organisms, as well as atypical bacteria such as chlamydia, mycoplasma, spirochetes, and even protozoa. Tetracyclines
• Hydroxychloroquine Hydroxychloroquine A chemotherapeutic agent that acts against erythrocytic forms of malarial parasites. Hydroxychloroquine appears to concentrate in food vacuoles of affected protozoa. It inhibits plasmodial heme polymerase. Immunosuppressants
• Cyclosporine Cyclosporine A cyclic undecapeptide from an extract of soil fungi. It is a powerful immunosupressant with a specific action on T-lymphocytes. It is used for the prophylaxis of graft rejection in organ and tissue transplantation. Immunosuppressants
• Mycophenolate Mycophenolate Immunosuppressants mofetil
• Azathioprine Azathioprine An immunosuppressive agent used in combination with cyclophosphamide and hydroxychloroquine in the treatment of rheumatoid arthritis. According to the fourth annual report on carcinogens, this substance has been listed as a known carcinogen. Immunosuppressants

Differential Diagnosis

• Irritant contact dermatitis Contact dermatitis A type of acute or chronic skin reaction in which sensitivity is manifested by reactivity to materials or substances coming in contact with the skin. It may involve allergic or non-allergic mechanisms. Male Genitourinary Examination: skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions condition that results from exposure to a physical or chemical irritant. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship present with erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion, edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema, vesicles Vesicles Female Genitourinary Examination, and oozing that are limited to areas where the offending substance was present.
• Discoid lupus erythematosus Discoid Lupus Erythematosus Alopecia: a chronic autoimmune skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions condition characterized by erythematous scaly plaques that often result in inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation, scarring Scarring Inflammation, and atrophy Atrophy Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes. Cellular Adaptation on the face, neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess, ears, and scalp. The condition may occur with or without concurrent systemic lupus erythematosus Systemic lupus erythematosus Systemic lupus erythematosus (SLE) is a chronic autoimmune, inflammatory condition that causes immune-complex deposition in organs, resulting in systemic manifestations. Women, particularly those of African American descent, are more commonly affected. Systemic Lupus Erythematosus.
• Lichenoid drug eruption: the symmetric cutaneous eruption that appears as erythematous papules on the trunk and extremities after taking a drug. Wickham’s striae is usually not present. In most cases, the condition will spontaneously resolve with discontinuation of the offending drug.
• Eczema Eczema Atopic dermatitis, also known as eczema, is a chronic, relapsing, pruritic, inflammatory skin disease that occurs more frequently in children, although adults can also be affected. The condition is often associated with elevated serum levels of IgE and a personal or family history of atopy. Skin dryness, erythema, oozing, crusting, and lichenification are present. Atopic Dermatitis (Eczema) (seen in atopic dermatitis Dermatitis Any inflammation of the skin. Atopic Dermatitis (Eczema)): a chronic pruritic skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions condition commonly found in children. Eczema Eczema Atopic dermatitis, also known as eczema, is a chronic, relapsing, pruritic, inflammatory skin disease that occurs more frequently in children, although adults can also be affected. The condition is often associated with elevated serum levels of IgE and a personal or family history of atopy. Skin dryness, erythema, oozing, crusting, and lichenification are present. Atopic Dermatitis (Eczema) is associated with asthma Asthma Asthma is a chronic inflammatory respiratory condition characterized by bronchial hyperresponsiveness and airflow obstruction. The disease is believed to result from the complex interaction of host and environmental factors that increase disease predisposition, with inflammation causing symptoms and structural changes. Patients typically present with wheezing, cough, and dyspnea. Asthma. Lesions are dry, pruritic, red papules mainly located on the cheeks Cheeks The part of the face that is below the eye and to the side of the nose and mouth. Melasma or scalp (in infants) and flexural areas of extremities (older children). 
• Seborrheic dermatitis Dermatitis Any inflammation of the skin. Atopic Dermatitis (Eczema): a chronic inflammatory dermatosis characterized by the presence of greasy, red (inflamed) skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions lesions affecting the scalp (as dandruff Dandruff Excessive shedding of dry scaly material from the scalp in humans. Seborrheic Dermatitis), posterior aspect of the neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess, and the forehead Forehead The part of the face above the eyes. Melasma. The condition is linked to increased sebum Sebum The oily substance secreted by sebaceous glands. It is composed of keratin, fat, and cellular debris. Infectious Folliculitis production and possible colonization Colonization Bacteriology of the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions by fungi Fungi A kingdom of eukaryotic, heterotrophic organisms that live parasitically as saprobes, including mushrooms; yeasts; smuts, molds, etc. They reproduce either sexually or asexually, and have life cycles that range from simple to complex. Filamentous fungi, commonly known as molds, refer to those that grow as multicellular colonies. Mycology of the genus Malassezia Malassezia Malassezia is a lipophilic yeast commonly found on the skin surfaces of many animals, including humans. In the presence of certain environments or triggers, this fungus can cause pathologic diseases ranging from superficial skin conditions (tinea versicolor and dermatitis) to invasive disease (e.g., Malassezia folliculitis, catheter-associated fungemia, meningitis, and urinary tract infections). Malassezia Fungi.
• Pityriasis rosea Pityriasis rosea Pityriasis rosea is an acute, self-limited skin disease. The etiology is not known, and it commonly occurs in young adults. Patients initially present with a single, ovoid “herald patch.” This is followed by diffuse, pruritic, scaly, oval lesions over the trunk (often in a “Christmas tree” distribution on the back) and extremities. Pityriasis Rosea: skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions condition affecting mostly older children and young adults. Pityriasis rosea Pityriasis rosea Pityriasis rosea is an acute, self-limited skin disease. The etiology is not known, and it commonly occurs in young adults. Patients initially present with a single, ovoid “herald patch.” This is followed by diffuse, pruritic, scaly, oval lesions over the trunk (often in a “Christmas tree” distribution on the back) and extremities. Pityriasis Rosea begins with a single “herald” patch Patch Nonpalpable lesion > 1 cm in diameter Generalized and Localized Rashes on the chest, neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess, or back. This is followed by smaller pruritic salmon-colored oval plaques with scaling located on the trunk and extremities. The characteristic morphology is a “Christmas tree” pattern on the back.
• Plaque Plaque Primary Skin Lesions psoriasis Psoriasis Psoriasis is a common T-cell-mediated inflammatory skin condition. The etiology is unknown, but is thought to be due to genetic inheritance and environmental triggers. There are 4 major subtypes, with the most common form being chronic plaque psoriasis. Psoriasis: lesions are characterized by well-demarcated, erythematous, symmetrically distributed plaques with overlying silver scales Scales Dry or greasy masses of keratin that represent thickened stratum corneum. Secondary Skin Lesions involving the scalp and extensor surfaces (elbows and knees). 
• Lichen simplex chronicus Lichen Simplex Chronicus A benign vulvar skin disorder characterized by hyperkeratosis (thickening of the skin) that occurs secondary to chronic vulvar irritation Benign Vulvar Conditions: a form of neurodermatitis caused by the itch-scratch cycle, leading to plaques and thickened skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions. Locations affected are areas accessible to scratching. Management includes potent topical steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors.