Molluscum Contagiosum

Overview

Epidemiology

• 1% of all diagnosed 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 disorders
• Usually presents in children < 5 years of age or adolescents
• Increased 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 in hot, humid climates
• Slight predominance in boys
• More common in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with:
  • HIV HIV Anti-HIV Drugs
  • Atopic dermatitis Dermatitis Any inflammation of the skin. Atopic Dermatitis (Eczema)

Etiology and transmission

• Molluscum contagiosum 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 (MCV) is a double-stranded, linear, DNA DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). DNA Types and Structure poxvirus.
• Transmission:
  • Exposure to infected individuals (skin-to-skin contact):
    • Sexually transmitted
    • Peripartum
  • Fomites Fomites Inanimate objects that carry pathogenic microorganisms and thus can serve as the source of infection. Microorganisms typically survive on fomites for minutes or hours. Common fomites include clothing, tissue paper, hairbrushes, and cooking and eating utensils. Adenovirus (e.g., towels, toys, razors)
  • Autoinoculation (scraping)

Pathophysiology

• Incubation Incubation The amount time between exposure to an infectious agent and becoming symptomatic. Rabies Virus period from 2 weeks to 6 months
• 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 infects only 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 → localized to 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
• Inhibits innate immunity Innate immunity The capacity of a normal organism to remain unaffected by microorganisms and their toxins. It results from the presence of naturally occurring anti-infective agents, constitutional factors such as body temperature and immediate acting immune cells such as natural killer cells. Innate Immunity: Phagocytes and Antigen Presentation via antiviral Antiviral Antivirals for Hepatitis B protein production → persistent infection

Histopathology

• Hyperkeratosis Hyperkeratosis Ichthyosis Vulgaris (thickened 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)
• Epidermal proliferation into the 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
• Henderson-Paterson bodies: inclusions visible in the 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 of the basal, spinous, and granular layers of the 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

Clinical Presentation and Diagnosis

Clinical presentation of lesions

• Usually no systemic symptoms
• Dermatological features:
  • Shape and color:
    • Dome shaped
    • Pearly papules
    • Flesh colored
    • 2–6 mm MM Multiple myeloma (MM) is a malignant condition of plasma cells (activated B lymphocytes) primarily seen in the elderly. Monoclonal proliferation of plasma cells results in cytokine-driven osteoclastic activity and excessive secretion of IgG antibodies. Multiple Myeloma in diameter
    • Central umbilication
  • Usually multiple and occur in clusters
  • Rarely associated with pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema) or tenderness
  • Distribution:
    • Children: 
      • Face
      • Trunk
      • Axilla Axilla The axilla is a pyramid-shaped space located between the upper thorax and the arm. The axilla has a base, an apex, and 4 walls (anterior, medial, lateral, posterior). The base of the pyramid is made up of the axillary skin. The apex is the axillary inlet, located between the 1st rib, superior border of the scapula, and clavicle. Axilla and Brachial Plexus: Anatomy
      • Antecubital fossa
      • Popliteal fossa Popliteal fossa The popliteal fossa or the “knee pit” is a diamond-shaped, fat-filled, shallow depression on the posterior aspect of the knee joint. The popliteal fossa is located at the dorsal aspect of the knee and contains an increased number of lymph nodes as well as structures of the neurovascular system that travel from the thigh to the lower leg. Popliteal Fossa: Anatomy
    • Adults: 
      • Anogenital area
      • Abdomen
      • Thighs
    • Palms and soles not involved
• Immunocompromised immunocompromised A human or animal whose immunologic mechanism is deficient because of an immunodeficiency disorder or other disease or as the result of the administration of immunosuppressive drugs or radiation. Gastroenteritis individuals may have widespread/diffuse eruptions.

Diagnosis

• Clinical diagnosis is sufficient.
• Histopathological analysis to confirm diagnosis
• Lesions in inguinal region Inguinal region Anterior Abdominal Wall: Anatomy → STD panel to rule out accompanying STIs STIs Sexually transmitted infections (STIs) or sexually transmitted diseases (STDs) 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)

Management

Treatment

• No treatment is necessary for healthy individuals as it is a self-limiting Self-Limiting Meningitis in Children disease.
• Patient education:
  • Complete resolution can take up to 1 year.
  • Avoid sharing towels and sheets, and do not shave across lesions.
  • Cover lesions with a tight bandage.
  • Practice safe sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria.
• Management for cosmetic reasons or to reduce transmission:
  • Physical removal (1st-line therapy):
    • Cryotherapy Cryotherapy A form of therapy consisting in the local or general use of cold. The selective destruction of tissue by extreme cold or freezing is cryosurgery. Chondrosarcoma (liquid nitrogen Nitrogen An element with the atomic symbol n, atomic number 7, and atomic weight [14. 00643; 14. 00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth’s atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells. Urea Cycle)
    • Curettage Curettage A scraping, usually of the interior of a cavity or tract, for removal of new growth or other abnormal tissue, or to obtain material for tissue diagnosis. It is performed with a curet (curette), a spoon-shaped instrument designed for that purpose. Benign Bone Tumors
    • Cantharidin (topical blistering agent to be applied only by a physician)
  • Topical treatment (applied by the patient):
    • Podophyllotoxin
    • Potassium Potassium An element in the alkali group of metals with an atomic symbol k, atomic number 19, and atomic weight 39. 10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the water-electrolyte balance. Hyperkalemia hydroxide/salicylic acid
    • Benzoyl peroxide
    • Tretinoin
    • Topical imiquimod Imiquimod A topically-applied aminoquinoline immune modulator that induces interferon production. It is used in the treatment of external genital and perianal warts, superficial carcinoma, basal cell; and actinic keratosis. Hypertrophic and Keloid Scars
    • Oral cimetidine Cimetidine A histamine congener, it competitively inhibits histamine binding to histamine h2 receptors. Cimetidine has a range of pharmacological actions. It inhibits gastric acid secretion, as well as pepsin and gastrin output. Antihistamines
• Immunocompromised immunocompromised A human or animal whose immunologic mechanism is deficient because of an immunodeficiency disorder or other disease or as the result of the administration of immunosuppressive drugs or radiation. Gastroenteritis patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship:
  • Antiretroviral therapy Antiretroviral therapy Antiretroviral therapy (ART) targets the replication cycle of the human immunodeficiency virus (HIV) and is classified based on the viral enzyme or mechanism that is inhibited. The goal of therapy is to suppress viral replication to reach the outcome of undetected viral load. Anti-HIV Drugs for patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with HIV HIV Anti-HIV Drugs
  • Interferon-alpha Interferon-alpha One of the type I interferons produced by peripheral blood leukocytes or lymphoblastoid cells. In addition to antiviral activity, it activates natural killer cells and B-lymphocytes, and down-regulates vascular endothelial growth factor expression through pi-3 kinase and mapk kinases signaling pathways. Interferons or cidofovir Cidofovir An acyclic nucleoside phosphonate that acts as a competitive inhibitor of viral DNA polymerases. It is used in the treatment of retinitis caused by cytomegalovirus infections and may also be useful for treating herpesvirus infections. Antivirals for Herpes Virus

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas

• Spontaneous resolution within 1 year in immunocompetent individuals
• Some cases may persist for 3‒5 years.

Complications

• Cellulitis Cellulitis Cellulitis is a common infection caused by bacteria that affects the dermis and subcutaneous tissue of the skin. It is frequently caused by Staphylococcus aureus and Streptococcus pyogenes. The skin infection presents as an erythematous and edematous area with warmth and tenderness. Cellulitis
• Conjunctivitis Conjunctivitis Conjunctivitis is a common inflammation of the bulbar and/or palpebral conjunctiva. It can be classified into infectious (mostly viral) and noninfectious conjunctivitis, which includes allergic causes. Patients commonly present with red eyes, increased tearing, burning, foreign body sensation, and photophobia. Conjunctivitis (if present on the eyelids Eyelids Each of the upper and lower folds of skin which cover the eye when closed. Blepharitis)
• Abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease
• Scarring Scarring Inflammation/ hypopigmentation Hypopigmentation A condition caused by a deficiency or a loss of melanin pigmentation in the epidermis, also known as hypomelanosis. Hypopigmentation can be localized or generalized, and may result from genetic defects, trauma, inflammation, or infections. Malassezia Fungi after cryotherapy Cryotherapy A form of therapy consisting in the local or general use of cold. The selective destruction of tissue by extreme cold or freezing is cryosurgery. Chondrosarcoma

Differential Diagnosis

• Basal cell Basal Cell Erythema Multiforme carcinoma: pearly 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 that may present as ulceration Ulceration Corneal Abrasions, Erosion, and Ulcers and mimic the lesions of molluscum contagiosum. Basal cell Basal Cell Erythema Multiforme carcinoma is common in the elderly. Lesions are found in sun-exposed areas. A biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma may be necessary to differentiate between basal cell Basal Cell Erythema Multiforme carcinoma and molluscum contagiosum.
• Condyloma Condyloma Sexually transmitted form of anogenital warty growth caused by the human papillomaviruses. Male Genitourinary Examination acuminatum: flesh-colored pedunculate lesions secondary to HPV HPV Human papillomavirus (HPV) is a nonenveloped, circular, double-stranded DNA virus belonging to the Papillomaviridae family. Humans are the only reservoir, and transmission occurs through close skin-to-skin or sexual contact. Human papillomaviruses infect basal epithelial cells and can affect cell-regulatory proteins to result in cell proliferation. Papillomavirus (HPV) infection. Lesions are mainly present in the anogenital region. Condyloma Condyloma Sexually transmitted form of anogenital warty growth caused by the human papillomaviruses. Male Genitourinary Examination acuminatum is usually sexually transmitted and can be prevented via vaccination Vaccination Vaccination is the administration of a substance to induce the immune system to develop protection against a disease. Unlike passive immunization, which involves the administration of pre-performed antibodies, active immunization constitutes the administration of a vaccine to stimulate the body to produce its own antibodies. Vaccination. Treatment of lesions is similar to the approach used to treat molluscum contagiosum.
• Condylomata lata Condylomata Lata Syphilis: smooth flesh-like lesions appearing gray or white, located in the vaginal, penile, or anal area, occurring secondary to a syphilis Syphilis Syphilis is a bacterial infection caused by the spirochete Treponema pallidum pallidum (T. p. pallidum), which is usually spread through sexual contact. Syphilis has 4 clinical stages: primary, secondary, latent, and tertiary. Syphilis infection. Condylomata lata Condylomata Lata Syphilis is an 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) and the treatment for primary syphilis Primary Syphilis Syphilis is with antibiotics. Treatment of lesions in condylomata lata Condylomata Lata Syphilis is similar to the approach used to treat the lesions in molluscum contagiosum. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship should be examined for other STIs STIs Sexually transmitted infections (STIs) or sexually transmitted diseases (STDs) 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).
• Herpes: a painful condition with ulcerating lesions caused by HSV HSV Herpes simplex virus (HSV) is a double-stranded DNA virus belonging to the family Herpesviridae. Herpes simplex virus commonly causes recurrent infections involving the skin and mucosal surfaces, including the mouth, lips, eyes, and genitals. Herpes Simplex Virus 1 and 2 that presents with systemic symptoms. Lesions are more pustular, blistering, and erythematous than those occurring in molluscum contagiosum. Treatment is supportive as infection cannot be completely eradicated. Outbreaks Outbreaks Sudden increase in the incidence of a disease. The concept includes epidemics and pandemics. Influenza Viruses/Influenza are treated with acyclovir Acyclovir A guanosine analog that acts as an antimetabolite. Viruses are especially susceptible. Used especially against herpes. Herpes Zoster (Shingles).
• Varicella zoster: an infection caused by the Varicella zoster 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. Flesh-colored lesions with central umbilication present with systemic manifestations of 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 coryza Coryza Inflammation of the nasal mucosa, the mucous membrane lining the nasal cavities. Rhinitis. The lesions are extremely pruritic. Varicella-zoster infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease are self limiting and of short duration, and are typically treated only with supportive care in immunocompetent individuals. Infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease can be prevented by vaccination Vaccination Vaccination is the administration of a substance to induce the immune system to develop protection against a disease. Unlike passive immunization, which involves the administration of pre-performed antibodies, active immunization constitutes the administration of a vaccine to stimulate the body to produce its own antibodies. Vaccination.