Molluscum contagiosum

  • Definition
    • Molluscum contagiosum is a viral skin infection that causes raised, pearl-like papules or nodules on the skin.

  • Causes
    • Molluscum contagiosum is caused by a virus that is a member of the poxvirus family. You can get the infection in different ways.

      This is a common infection in children and occurs when a child comes into direct contact with a lesion or an object that has the virus on it. The infection is most often seen on the face, neck, armpit, arms, and hands. But it may occur anywhere on the body, except the palms and soles.

      The virus can spread through contact with contaminated objects, such as towels, clothing, or toys.

      The virus also spreads by sexual contact. Early lesions on the genitals may be mistaken for herpes or warts. But unlike herpes, these lesions are painless.

      Persons with a weakened immune system (due to conditions such as HIV/AIDS) may have a rapidly spreading case of molluscum contagiosum.

  • Symptoms
    • The infection on the skin begins as a small, painless papule. It may become raised to a pearly, flesh-colored nodule. The papule often has a dimple in the center. Scratching or other irritation causes the virus to spread in a line or in groups, called crops.

      The papules are about 2 to 5 millimeters wide. Usually, there is no inflammation (swelling and redness) and no redness unless you have been digging or scratching at the lesions (abnormal areas on the skin).

      The skin lesion commonly has a central core or plug of white, cheesy or waxy material.

      In adults, the lesions are commonly seen on the genitals, abdomen, and inner thigh.

  • Exams and Tests
    • Diagnosis is based on the appearance of the lesion and can be confirmed by a skin biopsy. The health care provider will examine the lesion to rule out other disorders and to determine other underlying disorders.

  • Treatment
    • In people with a healthy immune system, the disorder usually goes away on its own over months to years. But the lesions can spread before they go away.

      Individual lesions may be removed surgically. This is done by scraping, de-coring, freezing, or through needle electrosurgery. Laser treatment may also be used. Surgical removal of individual lesions may result in scarring.

      Medicines, such as salicylic acid preparations used to remove warts, may be helpful. But these medicines can cause blistering that leads to temporary skin discoloration. Cantharidin, commonly called beetle juice, is the most common solution used to treat the lesions in the provider's office. Tretinoin cream or imiquimod cream may also be prescribed.

  • Outlook (Prognosis)
    • Molluscum contagiosum lesions may persist from a few months to a few years. They eventually disappear without scarring, unless there has been excessive scratching, which may leave marks.

      The lesions usually all disappear within 6 to 18 months. The disorder may persist in immunosuppressed people.

  • Possible Complications
    • Problems that can occur include any of the following:

      • Persistence, spread, or recurrence of lesions
      • Secondary bacterial skin infections
  • When to Contact a Medical Professional
    • Call for an appointment with your provider if:

      • You have a skin problem that looks like molluscum contagiosum
      • Molluscum contagiosum lesions persist or spread, or if new symptoms appear 
  • Prevention
    • Avoid direct contact with the skin lesions. Do not share towels or other personal items, such as razors and make-up, with other people.

      Avoiding sex can also prevent getting the molluscum virus and other STDs. You can also avoid STDs by having a monogamous sexual relationship with a partner known to be disease-free.

      Male and female condoms can't fully protect you, as the virus can be on areas not covered by the condom. Even so, condoms should still be used every time the disease status of a sexual partner is unknown. Condoms reduce your chances of getting or spreading STDs.

  • References
    • Damon IK. Other poxviruses that infect humans. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 136.

      Javed A, Coulson I. Molluscum contagiosum. In: Lebwohl MG, Heymann WR, Berth-Jones J, Coulson I, eds. Treatment of Skin Disease: Comprehensive Therapeutic Strategies. 4th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 149.