Molluscum contagiosum is a viral skin infection caused by a DNA poxvirus. It manifests as smooth firm papules with a central umbilication. Molluscum contagiosum may be spread by direct contact (most often in children), autoinoculation, or via sexual transmission in adults. Molluscum contagiosum infections have also been associated with swimming pool facilities via fomites.
In adults, molluscum contagiosum is more commonly distributed on the mons pubis, the genitalia, perineum, inner thighs, and lower abdomen. The distribution in children is trunk and extremities. Consider underlying immunodeficiency, such as HIV disease, in patients with widespread disease or large, atypical papules and/or plaques.
Many cases are asymptomatic, but there can be surrounding irritation in association with pruritus. Molluscum may occur in tattoos.
Papules may persist for several months and up to 2 years before disappearing. In the immunocompetent host, the disease tends to be self-limited.
Immunosuppressed patients and those with human immunodeficiency virus (HIV) / 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 several immunosuppressed states including malignancies, severe combined immunodeficiency, transplant patients, and in those receiving chemotherapy. Sarcoidosis and atopic dermatitis also predispose patients to molluscum contagiosum infections, most likely due to abnormal T-cell immunity.
B08.1 – Molluscum contagiosum
40070004 – Molluscum contagiosum
- Herpes simplex
- Flat warts
- Sebaceous hyperplasia
- Lobular capillary hemangioma (pyogenic granuloma)
- Lichen planus
- Basal cell carcinoma