Molluscum contagiosum is a viral infection that produces small, painless blisters that may, at first, resemble genital warts. It may cause serious complications in people with immunodeficiency disorders (e.g., HIV/AIDS).
Incidence and Prevalence of Molluscum
Molluscum contagiosum accounts for fewer than 3 percent of STDs in the United States. It usually occurs in people 20 to 40 years old.
Causes of Molluscum
The disease is most often spread through direct skin-to-skin contact. Transmission through shared items (e.g., towels, gym equipment) occurs infrequently in adults. Scratching, picking, or breaking the blisters can spread the infection to other areas of the body. Molluscum contagiosum also is spread through sexual contact and commonly affects the pubic area, groin, thighs, buttocks, and external genitalia.
Infected children often spread the disease by scratching the blisters and touching one another; blisters usually appear on the face. Salivary transmission occurs among young children.
Signs and Symptoms of Molluscum
Blisters, or papules, usually appear about 6 weeks after exposure but may appear within 1 week. They form at the location where the virus entered the body, usually on the genitals, thighs, or lower abdomen. A person with a weakened immune system may experience outbreaks on the face or scalp. The blisters are waxy and raised, with a dimple on top. They can be flesh-colored, white, pink, yellow, or clear. Single papules may appear first, then multiply to form clusters that sometimes resemble genital warts. Itching is common, but pain is rare. A few patients experience red, scaly skin around the blisters.
Individual blisters may resolve on their own in about 2 months, but an outbreak can last 6 months to 3 years.
The blisters are distinctive, so diagnosis is typically made by observation. Doctors confirm the diagnosis with a biopsy and microscopic examination of biopsied tissue. Often, a physician removes ("unroofs") the top of a blister and push out its core. Molluscum contagiosum blisters have a characteristic white core and bleed following unroofing.
Treatment for Molluscum
Although the virus remains in the body, a healthy person's immune system usually controls outbreaks and suppresses blister formation. Outbreaks can recur, and they are usually associated with a weakened immune system. There is no specific treatment. Blisters may be removed surgically by cutting, burning, chemical destruction, or freezing with liquid nitrogen. These procedures are done in the office under local anesthetic. Retinoids (e.g., Retin A), an acne treatment, also may be used. Increased sun sensitivity is a common side effect.