Pityriasis Rosea

Epidemiology and Etiology

Epidemiology

• Incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency: 0.5%–2%
• Sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria: women > men
• Common age group: 15–30 years
• Seasonal variation: more common in winter and spring (in temperate climates)

Etiology

• Idiopathic Idiopathic Dermatomyositis
• Possibly infectious; has been associated with:
  • HHV-6 HHV-6 Human herpesvirus (HHV)-6 and HHV-7 are similar double-stranded DNA viruses belonging to the Herpesviridae family. Human herpesviruses are ubiquitous and infections are commonly contracted during childhood. Human Herpesvirus 6 and 7
  • HHV-7 HHV-7 Human herpesvirus (HHV)-6 and HHV-7 are similar double-stranded DNA viruses belonging to the Herpesviridae family. Human herpesviruses are ubiquitous and infections are commonly contracted during childhood. Human Herpesvirus 6 and 7
  • HHV-8
  • Influenza Influenza Influenza viruses are members of the Orthomyxoviridae family and the causative organisms of influenza, a highly contagious febrile respiratory disease. There are 3 primary influenza viruses (A, B, and C) and various subtypes, which are classified based on their virulent surface antigens, hemagglutinin (HA) and neuraminidase (NA). Influenza typically presents with a fever, myalgia, headache, and symptoms of an upper respiratory infection. Influenza Viruses/Influenza (H1N1)

Clinical Presentation

Prodrome Prodrome Symptoms that appear 24–48 hours prior to migraine onset. Migraine Headache

• Occurs in a minority of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship a week prior to appearance of cutaneous lesions
• Symptoms:
  • Malaise Malaise Tick-borne Encephalitis Virus 
  • Headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess
  • Fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever  
  • Arthralgia Arthralgia Pain in the joint. Rheumatic Fever
  • Sore throat Sore throat Pharyngitis is an inflammation of the back of the throat (pharynx). Pharyngitis is usually caused by an upper respiratory tract infection, which is viral in most cases. It typically results in a sore throat and fever. Other symptoms may include a runny nose, cough, headache, and hoarseness. Pharyngitis

Cutaneous eruption

Primary:

• Called the “herald” or  “mother” patch Patch Nonpalpable lesion > 1 cm in diameter Generalized and Localized Rashes
• Single lesion
• Round or oval 
• 2–5 cm in diameter
• Well-defined borders
• Pink or salmon-colored 
• Collarette Collarette Blepharitis scaling:
  • Fine scaling that remains attached near the border
  • Scale Scale Dermatologic Examination lifts up near the center of the lesion.
  • Center may appear wrinkled.
• Located on: 
  • Back
  • Chest 
  • Neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess

Secondary:

• Occurs within 1–2 weeks after the herald patch Patch Nonpalpable lesion > 1 cm in diameter Generalized and Localized Rashes 
• Same features as the herald patch Patch Nonpalpable lesion > 1 cm in diameter Generalized and Localized Rashes, except:
  • Smaller (< 1.5 cm)
  • Appears in crops
  • Symmetrical Symmetrical Dermatologic Examination
  • Bilateral 
• Located on: 
  • Back
  • Chest
  • Extremities
• “Christmas tree” distribution 
  • Term used to describe the rash Rash Rocky Mountain Spotted Fever’s appearance on the back
  • Due to the lesions’ orientation Orientation Awareness of oneself in relation to time, place and person. Psychiatric Assessment along 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 tension lines (Langer’s lines)
• Pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema) usually present (severe in 25% of cases)
• Usually resolves spontaneously in 6–8 weeks: 
  • Generally leaves few residual cutaneous changes
  • Postinflammatory hyperpigmentation Postinflammatory Hyperpigmentation Acne Vulgaris is common in dark-skinned patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship.

Diagnosis and Management

Diagnosis

Pityriasis rosea is a clinical diagnosis. The following tests may be used if the diagnosis is not clear.

• Skin biopsy Skin Biopsy Secondary Skin Lesions:
  • Rarely needed
  • Findings:
    • Superficial perivascular infiltrate ( 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 and histiocytes Histiocytes Macrophages found in the tissues, as opposed to those found in the blood (monocytes) or serous cavities (serous membrane). Chronic Granulomatous Disease)
    • Focal parakeratosis Parakeratosis Persistence of the nuclei of the keratinocytes into the stratum corneum of the skin. This is a normal state only in the epithelium of true mucous membranes in the mouth and vagina. Actinic Keratosis
• KOH examination of scales Scales Dry or greasy masses of keratin that represent thickened stratum corneum. Secondary Skin Lesions → rule out tinea corporis Tinea corporis Dermatophytes/Tinea Infections 
• Rapid plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products reagin and VDRL VDRL Treponema tests → rule out secondary syphilis Secondary Syphilis Syphilis

Management

Pityriasis rosea is a self-limiting Self-Limiting Meningitis in Children condition; therefore, usually no treatment is required. 

• General:
  • Reassurance Reassurance Clinician–Patient Relationship
  • Emollients
• Medical management:
  • Pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema): 
    • Topical corticosteroids Corticosteroids Chorioretinitis 
    • 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
    • Menthol
  • Severe symptoms: 
    • Acyclovir Acyclovir A guanosine analog that acts as an antimetabolite. Viruses are especially susceptible. Used especially against herpes. Herpes Zoster (Shingles) 
    • Ultraviolet light Ultraviolet light That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-uv or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-uv or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants. Bullous Pemphigoid and Pemphigus Vulgaris therapy

Complications

• In pregnant patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship (especially if occurring within the first 15 weeks):
  • Miscarriage Miscarriage Spontaneous abortion, also known as miscarriage, is the loss of a pregnancy before 20 weeks’ gestation. However, the layperson use of the term “abortion” is often intended to refer to induced termination of a pregnancy, whereas “miscarriage” is preferred for spontaneous loss. Spontaneous Abortion and spontaneous abortion Abortion Expulsion of the product of fertilization before completing the term of gestation and without deliberate interference. Spontaneous Abortion
  • Premature Premature Childbirth before 37 weeks of pregnancy (259 days from the first day of the mother’s last menstrual period, or 245 days after fertilization). Necrotizing Enterocolitis delivery
  • Neonatal hypotonia Hypotonia Duchenne Muscular Dystrophy 
• Bacterial superinfections are rare.

Differential Diagnosis

• Tinea corporis Tinea corporis Dermatophytes/Tinea Infections: a superficial fungal infection 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 that can affect the face, trunk, and extremities: The lesions of tinea corporis Tinea corporis Dermatophytes/Tinea Infections are characterized by peripheral scaling, central clearing, and erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion. The appearance may be similar to that of the herald patch Patch Nonpalpable lesion > 1 cm in diameter Generalized and Localized Rashes of pityriasis rosea. The diagnosis is usually clinical, though a KOH examination would show fungal hyphae Hyphae Microscopic threadlike filaments in fungi that are filled with a layer of protoplasm. Collectively, the hyphae make up the mycelium. Mycology. Management includes topical or oral antifungal Antifungal Azoles medications. 
• Tinea versicolor Tinea versicolor A common chronic, noninflammatory and usually symptomless disorder, characterized by the occurrence of multiple macular patches of all sizes and shapes, and varying in pigmentation from fawn-colored to brown. It is seen most frequently in hot, humid, tropical regions and is mostly caused by Malassezia furfur (formerly Pityrosporum orbiculare). Malassezia Fungi: a fungal 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 infection due to 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 furfur: Multiple scaly patches Patches Vitiligo of various colors (e.g., brown, salmon, pink, or white) can occur on the trunk, abdomen, neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess, and face. The diagnosis is clinical and is confirmed with KOH examination, which shows fungal hyphae Hyphae Microscopic threadlike filaments in fungi that are filled with a layer of protoplasm. Collectively, the hyphae make up the mycelium. Mycology and budding Budding Mycology. Management includes topical or oral antifungal Antifungal Azoles medications.
• Secondary syphilis Secondary Syphilis Syphilis: STI STI Sexually transmitted infections (STIs) are infections that spread either by vaginal intercourse, anal sex, or oral sex. Symptoms and signs may include vaginal discharge, penile discharge, dysuria, skin lesions (e.g., warts, ulcers) on or around the genitals, and pelvic pain. Some infections can lead to infertility and chronic debilitating disease. Sexually Transmitted Infections (STIs) caused by Treponema pallidum Treponema pallidum The causative agent of venereal and non-venereal syphilis as well as yaws. Treponema: Secondary syphilis Secondary Syphilis Syphilis presents after the primary stage ( chancre Chancre The primary sore of syphilis, a painless indurated, eroded papule, occurring at the site of entry of the infection. Syphilis) with a maculopapular Maculopapular Dermatologic Examination rash Rash Rocky Mountain Spotted Fever (including the palms and soles), fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, and lymphadenopathy Lymphadenopathy Lymphadenopathy is lymph node enlargement (> 1 cm) and is benign and self-limited in most patients. Etiologies include malignancy, infection, and autoimmune disorders, as well as iatrogenic causes such as the use of certain medications. Generalized lymphadenopathy often indicates underlying systemic disease. Lymphadenopathy. Systemic manifestations are common and are not seen in pityriasis rosea. The diagnosis is established through nontreponemal and treponemal testing. Penicillin Penicillin Rheumatic Fever G is the antibiotic of choice in management.
• Guttate psoriasis Guttate Psoriasis Psoriasis: variant of 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: Guttate psoriasis Guttate Psoriasis Psoriasis is an immune-mediated inflammatory 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. This form of 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 presents with small, salmon-colored papules that look like dewdrops on 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. The trunk and extremities are commonly involved. No herald patch Patch Nonpalpable lesion > 1 cm in diameter Generalized and Localized Rashes precedes this eruption. The diagnosis is clinical, and management includes topical corticosteroids Corticosteroids Chorioretinitis, calcitriol Calcitriol The physiologically active form of vitamin d. It is formed primarily in the kidney by enzymatic hydroxylation of 25-hydroxycholecalciferol (calcifediol). Its production is stimulated by low blood calcium levels and parathyroid hormone. Calcitriol increases intestinal absorption of calcium and phosphorus, and in concert with parathyroid hormone increases bone resorption. Parathyroid Glands: Anatomy, and phototherapy Phototherapy Treatment of disease by exposure to light, especially by variously concentrated light rays or specific wavelengths. Hyperbilirubinemia of the Newborn. 
• Atopic dermatitis Dermatitis Any inflammation of the skin. Atopic Dermatitis (Eczema): a chronic, relapsing, inflammatory 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: Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship present with pruritic, erythematous, thickened, scaly patches Patches Vitiligo that frequently affect flexural regions. This distribution and the chronicity of the condition differentiates atopic dermatitis Dermatitis Any inflammation of the skin. Atopic Dermatitis (Eczema) from pityriasis rosea. The diagnosis is clinical. Management focuses on avoiding potential triggers Triggers Hereditary Angioedema (C1 Esterase Inhibitor Deficiency), 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, and immunosuppressive therapy.