Molluscum contagiosum
See also in: External and Internal Eye,AnogenitalAlerts and Notices
Synopsis
Molluscum contagiosum is a viral skin infection caused by a DNA poxvirus. It manifests as smooth, firm papules with central umbilication. Molluscum contagiosum may be spread by direct skin-skin contact (most often in children), via fomites (eg, towel, gym equipment), via autoinoculation, or via sexual transmission in adults.
In adults, molluscum contagiosum is commonly found on the mons pubis, the genitalia, perineum, inner thighs, and lower abdomen. The distribution in children is on the trunk and extremities. In underlying immunodeficiency, such as HIV disease, molluscum may be widespread or large, atypical papules and/or plaques may be seen.
Many cases are asymptomatic, but there can be surrounding irritation and pruritus.
In the immunocompetent host, the disease tends to be self-limited, but papules may persist for several months and up to 2 years before disappearing.
Immunosuppressed patients and those with HIV disease / AIDS are at particular risk of molluscum contagiosum infection, with a prevalence of 5%-18%. The number of lesions is inversely correlated with the CD4 count, and the presence of molluscum contagiosum lesions can actually indicate an AIDS diagnosis. Molluscum contagiosum has also been reported in association with several other immunosuppressed states including malignancies, severe combined immunodeficiency, organ and bone marrow transplants, and chemotherapy recipients. Sarcoidosis and atopic dermatitis also predispose patients to molluscum contagiosum infections, most likely due to abnormal T-cell immunity.
Codes
ICD10CM:B08.1 – Molluscum contagiosum
SNOMEDCT:
40070004 – Molluscum contagiosum
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Differential Diagnosis & Pitfalls
- Herpes simplex virus infection
- Flat warts
- Sebaceous hyperplasia
- Milia
- Nevus
- Lobular capillary hemangioma (pyogenic granuloma)
- Lichen planus
- Basal cell carcinoma
- Keratoacanthomas
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Last Reviewed:05/05/2021
Last Updated:05/05/2021
Last Updated:05/05/2021
Patient Information for Molluscum contagiosum
Overview
Molluscum contagiosum is a common viral infection of the skin. Although it typically goes away after several months, some cases can last a few years. Molluscum can spread to surrounding skin by scratching or rubbing (self-inoculation), and it can be spread to others by skin-to-skin contact or handling contaminated objects such as towels, clothing, and gym equipment. Poor hygiene and warm, moist climates encourage the spread of molluscum. Use of public or school swimming pools is also associated with infections.Who’s At Risk
Adults and teens are often infected by molluscum through sexual contact and tend to have genital lesions. Children ages 2-5 years are most commonly infected by close nonsexual contact, and lesions appear on the face, neck, arms, underarms, and hands (but usually not the palms). Individuals with eczema (atopic dermatitis) or a compromised immune system may be more susceptible to molluscum infection.Signs & Symptoms
In adults, the genital, stomach, buttock, and inner thigh areas are more often affected, as intimate contact with someone infected is the typical source of infection. Men are more often affected than women. Adults with a compromised immune system (such as those with HIV) may have severe, extensive infection.One or more small (1-6 mm) pink, white, or skin-colored, smooth papules (firm bumps), often with a tiny dot or depression in the center, occur in clusters and sometimes in a straight line from scratching (self-inoculation). In darker skin colors, the molluscum contagiosum lesions may appear skin-colored or purplish. In patients with an immune system deficiency, bumps can be larger than a thumbnail.
The infection can be considered:
- Mild – fewer than 10 lesions.
- Moderate – 10-50 lesions.
- Severe – more than 50 lesions.
Self-Care Guidelines
Treatment of mild molluscum infection is often not required, as these infections go away on their own. Care should be taken not to scratch or shave the affected areas to help avoid spreading them to other parts of the body. Keep the affected areas covered to avoid transmission of the virus to other people, and avoid sharing clothing, towels, and bedding with others.When to Seek Medical Care
In the case of moderate and severe infection when there is a concern of spread or concern about appearance, seek medical care. Consult a health professional if there is any new skin growth that you do not recognize.Treatments
- Removal with freezing (cryosurgery), scraping (curettage), or burning (electrocautery)
- Application of medications in office that cause a blistering reaction
- Prescription of a cream with either tretinoin (Retin-A) or imiquimod (Aldara, Zyclara), a prescription product also used to treat warts
Molluscum contagiosum
See also in: External and Internal Eye,Anogenital