Molluscum contagiosum is a common painless and usually harmless viral infection of the skin. Although it is painless and usually goes away after several months, some cases can last a few years. Molluscum can spread to surrounding skin by scratching or rubbing and can spread to others by skin-to-skin contact or handling contaminated objects such as towels, toys, and clothing. Poor hygiene and warm, moist climates encourage the spread of molluscum. Use of public or school swimming pools is associated with childhood infections.
Who's At Risk
Adults and teens are more often infected by molluscum through sexual contact and tend to have genital lesions. Children from age 1–5 are most commonly affected with lesions appearing on the face, neck, arms, armpits, and hands (but usually not the palms). Patients with eczema may be more severely affected by molluscum.
Signs and Symptoms
In adults, the genital, stomach, buttock, and inner thigh areas are more often affected as intimate contact with another is the typical source of infection. Men are more often affected than women. Adults with defective immune systems (such as with HIV) may have severe, extensive infection.
One or more small (1–5 mm) pink, white, or skin-colored, smooth, dome-shaped bumps, often with a tiny dot or depression in the center, occur in clusters and sometimes in a straight line from scratching and self-inoculation. In patients with a defective immune system, bumps can be larger than a nickel.
- Mild – under 10 spots
- Moderate – 10–50 spots
- Severe – over 50 spots
Treatment in mild infections is often not required, as molluscum infections goes away on their own. Care should be taken to not scratch or shave the areas. Keep the area covered to avoid transmission of the virus, and avoid sharing clothing, towels, and beds with others. Over-the-counter medications used to treat warts (with salicylic acid) may be helpful in removing the bumps, although these treatments can also be irritating.
When to Seek Medical Care
When there is a moderate or severe infection and there is a concern of spread or concern about appearance, seek medical care.
Treatments Your Physician May Prescribe
- Removal with freezing (cryosurgery), scraping (curettage), burning (electrocautery), or a laser
- Application of chemicals (a strong acid or alkali) or Cantharone (an extract from a blister beetle)
- Prescription of a cream with either tretinoin (derived from vitamin A) or imiquimod (a prescription product also used to treat warts, another type of viral infection)
Bolognia, Jean L., ed. Dermatology
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Freedberg, Irwin M., ed. Fitzpatrick's Dermatology in General Medicine
ed. pp.1861, 2114-2116, 2332. New York: McGraw-Hill, 2003.