Question:

A 4-year old girl presented with multiple skin coloured papules on her left chest wall for six months. The skin lesions were non-itchy and non-tender. On closer examination the skin papules have a smooth shiny surface, and some of them have an umbilicated centre.

Molluscum contagiosum is a self-limiting viral infection of the skin and mucous membrane characterized by pearly umbilicated papules. The skin lesions are smooth, skin coloured, white or slightly pink asymptomatic papules, some have a central depression on their surface. When present this 'umbilication' is an important diagnostic sign.

The virus is a large DNA pox virus. It is common in children under five years old and is contagious. Swimming pools, communal bathing facilities and close contact between children at play are the usual sources of transmission. The lesions may occur anywhere on the body, particularly on the face and neck. In adults, lesions often occur on genitalia or lower abdomen due to sexual transmission.

An individual lesion lasts about two months. Lesions undergoing spontaneous resolution often become acutely inflamed. The outbreak resolves spontaneously within a year and does not usually recur. Since the lesions are harmless and involute spontaneously, some doctors tend to leave these alone in children whom treatment is unappreciated. However the lesions remain a source of infection and many parents press for treatment. For adults with genital lesions, these may be treated with liquid nitrogen, or curettage and iodine from wooden applicator stick. The patient and their sexual partners should be screened for other sexually transmitted diseases.