Molluscum contagiosum is a common viral skin infection cause by a poxvirus. It is a common self-limited condition in children but can also affect adults. Its presents as small, firm, dome-shaped, pearly, umbilicated bumps that range in size from 1 to 6 mm. As they resolve, they may become inflamed and crusted. Molluscum contagiosum is a harmless virus but it may persist for months or occasionally for a couple of years. Rarely, tiny pit-like scars, may form after it heals. Molluscum frequently induces dermatitis in the affected or distant areas of the skin, especially in those with a history of eczema.

How do you catch molluscum contagiosum?

Molluscum contagiosum is spread from person to person (especially children) by direct skin contact. Sexual contact is a more common cause for transmission in adults.

People can get molluscum by sharing towels and clothing. Wrestlers and gymnasts may get it from touching infected mats. Skin-to-skin contact also spreads the virus.

What is the treatment for molluscum contagiosum?

There is no single perfect treatment of molluscum contagiosum since we are currently unable to kill the virus. In many cases the condition will ultimately self-resolve, however treatment may be requested when there are numerous or cosmetically significant lesions.

Medical treatments include:

  • Destructive therapies as curettage, cryotherapy, or cantharidin
  • Topical imiquimod, tretinoin, or cidofovir creams
  • Systemic therapy with cimetidine or cidofovir is indicated in those with widespread disease or immunodeficiency (as in HIV-infected patients)

What to expect after cantharidin treatment?

Cantharidin is a phosphodiesterase inhibitor that causes blister formation in the skin. It was originally derived from a blister beetle, but now is synthetically produced. It is often viewed to be a treatment of choice in young children as the treatment application is painless and effective.

Rinse the medication within 4-6 hours after application or sooner if blister formation is noted. Several hours after application, mild discomfort occasionally occurs. If needed, over-the-counter pain medication as acetaminophen or ibuprofen may help with discomfort.

One day after application, a small blister often forms. If the blister is large and uncomfortable, draining with a sterilized needle may reduce pain. Otherwise in 2-4 days the blister will crust or drain spontaneously leaving a shallow erosion. Apply Vaseline twice daily to the treated lesions to help with healing. Residual skin discoloration (lightening or darkening) may be seen in darker skin types. Scarring is rare.