Last Updated: February 26, 2018

Molluscum Contagiosum

Overview

Molluscum contagiosum is a common viral skin infection that causes benign lesions or “bumps” on the skin. The lesions are white, pink or flesh colored, and have a dip in the center. They are pearly in appearance, firm to the touch and range in size from two millimeters (i.e., pinhead) to five millimeters (i.e., pencil eraser) in diameter. Molluscum contagiosum is a contagious disease and can spread through direct contact with the skin of an infected person, or a contaminated surface.

photo of molluscum contagiosum bumps

Molluscum contagiosum is mostly observed in children, but can affect adults, in particular those with a compromised immune system. The lesions form anywhere on the body, but are uncommon on the palms of the hands or the soles of the feet. While the average person may see 10-20 lesions, the number increases significantly (more than 100) in those with compromised immunity, for example HIV/AIDS patients.

In otherwise healthy individuals, the disease clears up within 6-12 months. Topical treatment or surgical removal of the lesions may be recommended in order to prevent spread of the virus. Picking or surgical removal of the lesions may leave scars. Open lesions also carry the risk of secondary infection by bacteria.

Causes and Risk Factors

Molluscum contagiosum is caused by a poxvirus, the family of large DNA viruses that include smallpox and monkeypox. This virus lives in the skin lesions and can spread in two ways:

  1. Skin-to-skin contact: Direct contact with lesions allows the virus to transmit to a new individual. Sexual contact is the primary route of transmission in teens and adults. Children often pick up the virus through contact with other children in a childcare setting. Scratching and breaking the lesions increases transmission and can spread the virus to skin on other parts of the body (self-re-infection). It is not yet clear whether intact lesions can transmit virus.
  2. Contact with an infected surface: Direct contact with infected clothing, toys, bed linens, towels, mats and other personal items can transmit the molluscum contagiosum virus. Sharing of contaminated towels is the likely reason why swimming sports have a high risk of disease transmission.

Risk factors for molluscum contagiosum include the following:

Symptoms

Painless bumps on the skin’s surface are the main symptom associated with molluscum contagiosum. In children, they are found in all areas of the body, including the face, neck, armpits, arms and tops of the hands. In adults, the virus is commonly transmitted via sexual contact and is often found on the genitals, thighs and lower abdomen. The bumps appear roughly seven weeks following exposure to the virus and display the following features:

Diagnosis and Treatment

Molluscum contagiosum is diagnosed by visual inspection of the lesions. If necessary, a scraping from the lesion is analyzed by microscopy to verify the diagnosis.

The molluscum contagiosum lesions usually clear on their own over the course of 6-12 months, at which point the patient is no longer contagious. Intervention is rarely used in pediatric patients due to the risk of adverse reactions. However, in adults and those with compromised immune systems, the lesions are often treated in order to prevent further spread. The treatment options depend on the patient’s overall health and the frequency and location of lesions.

Prevention

Infection with molluscum contagiosum does not provide immunity to future re-infection. The following are effective ways to prevent transmission of molluscum contagiosum.

Sources

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Authored by: Tina Shahian, PhD