Molluscum contagiosum is a virus that causes characteristic pearly lesions on 
the surface of the skin. Small clusters of mollusca are a nuisance rather than a 
serious health problem. However, the mollusca can be more widespread and 
disfiguring in people with impaired cell-mediated immunity. Molluscum 
contagiosum virus is common in children. In adults it can also be contracted 
during sexual activity and might indicate a need for diagnostic testing for 
other, more serious sexually transmitted infections in young, sexually active 
adults.