[Mollusca contagiosa. From paediatric dermatology to sexually transmitted infection]

Molluscum contagiosum (MC) is a common cutaneous infection caused by the molluscipox virus (MCV) and can affect both children and adults. Molluscum contagiosum is relatively frequent in children aged 1-5 years old and can be localized almost anywhere on the body, but in adults it is regarded as a sexually transmitted infection (STI). MCV can be transmitted directly from person to person or by autoinoculation. MC in adults characteristically involves the genital area but extragenital appearance can be more typically seen in patients with immunosuppressive conditions, especially in HIV/AIDS. The onset of MC in HIV-positive individuals can be regarded as a part of the immune reconstitution inflammatory syndrome (IRIS). MC probably affects both sexes equally in children, whereas it seems that in adults the incidence is more prevalent in males. Therapy is controversial but may be considerably beneficial in preventing transmission or autoinoculation. At present there is no aetiological treatment of MC and most treatment options are mechanical sometimes causing discomfort or are not sufficiently evidence-based. Attention should be given to the extragenital site of involvement in adults and HIV testing should be recommended. Both children and adults with MC should be educated to avoid scratching and skin contact with others to prevent transmission and autoinoculation. Adult patients with MC should be carefully screened for other STIs and appropriately counseled.