Molluscum contagiosum is infection of the skin by a poxvirus that causes pink or white, dome-shaped, and smooth or waxy bumps.
The bumps are usually less than 1/4 inch (about 0.2 to 0.5 centimeters) in diameter, shaped like a dome, and have a tiny dimple in the center. The virus that causes molluscum is contagious. It spreads by direct contact with skin (for example, wrestling) or objects such as towels or sponges that have been touched by an infected person. The virus can probably be spread in water such as in pools, baths, or saunas. This infection is common among children. Genital lesions are often transmitted sexually in adults. Infection can be more widespread among people who have a weakened immune system such as those with HIV/AIDS or who use corticosteroids by mouth or receive cancer chemotherapy.
Molluscum contagiosum can infect any part of the skin except the palms of the hands and soles of the feet. The infection is typically chronic. In children, the bumps occur most commonly on the face, trunk, arms, and legs. In adults, the bumps occur most commonly on the penis, vulva, or around the pubic bone. The bumps usually are not itchy or painful and may be discovered only coincidentally during a physical examination. However, the bumps can become very inflamed (resembling a boil) and itchy as the body fights off the virus. This inflammation may indicate that the bumps will soon disappear.
Most growths disappear spontaneously in 1 to 2 years, but they can remain for 2 to 3 years. People with growths in the groin that were presumably acquired sexually should be treated to prevent spread of the infection. Otherwise, no treatment is needed unless the growths are disfiguring or otherwise bothersome. The growths can be treated by freezing (cryotherapy), burning with a laser or electric current, or removing their core with a needle or sharp scraping instrument (curette). Sometimes doctors apply trichloroacetic acid, podophyllin resin, or cantharidin to the bumps. Others prescribe tretinoin or imiquimod cream. These creams are applied for weeks or months.
Children do not need to be excluded from school or day care. However, their bumps should be covered to reduce the risk of spread to others.
Last full review/revision August 2014 by James G. H. Dinulos, MD