What is molluscum contagiosum?

Molluscum contagiosum is a skin infection caused by the virus Molluscum contagiosum. It produces benign raised bumps, or lesions, on the upper layers of your skin.

The small bumps are usually painless. They disappear on their own and rarely leave scars when they’re left untreated. The length of time the virus lasts varies for each person, but the bumps can remain from two months to four years.

Molluscum contagiosum is spread by direct contact with someone who has it or by touching an object contaminated with the virus, such as a towel or a piece of clothing.

Medication and surgical treatments are available, but treatment isn’t necessary in most cases. The virus can be more difficult to treat if you have a weakened immune system.

If you or your child comes into contact with the M. contagiosum virus, you may not see symptoms of infection for up to six months. The average incubation period is between two and seven weeks.

You may notice the appearance of a small group of painless lesions. These bumps can appear alone or in a patch of as many as 20. They’re usually:

  • very small, shiny, and smooth in appearance
  • flesh-colored, white, or pink
  • firm and shaped like a dome with a dent or dimple in the middle
  • filled with a central core of waxy material
  • between 2 to 5 millimeters in diameter, or between the size of the head of a pin and the size of an eraser on the top of a pencil
  • present anywhere except on the palms of your hands or the soles of your feet — specifically on the face, abdomen, torso, arms, and legs of children, or the inner thigh, genitals, and abdomen of adults

However, if you have a weakened immune system, you may have symptoms that are more significant. Lesions may be as large as 15 millimeters in diameter, which is about the size of a dime. The bumps appear more often on the face and are typically resistant to treatment.

You can get molluscum contagiosum by touching the lesions on the skin of a person who has this infection. Children can transmit the virus during normal play with other children.

Teens and adults are more likely to contract it through sexual contact. You can also become infected during contact sports that involve touching bare skin, such as wrestling or football.

The virus can survive on surfaces that have been touched by the skin of a person with molluscum contagiosum. So it’s possible to contract the virus by handling towels, clothing, toys, or other items that have been contaminated.

Sharing sports equipment that someone’s bare skin has touched can also cause the transfer of this virus. The virus can remain on the equipment to be transmitted to another person. This includes items such as baseball gloves, wrestling mats, and football helmets.

If you have molluscum contagiosum, you might spread the infection throughout your body. You can transfer the virus from one part of your body to another by touching, scratching, or shaving a bump and then touching another part of your body.

Anyone can get molluscum contagiosum, but certain groups of people are more likely to become infected than others. These groups include:

  • children between the ages of 1 and 10
  • people who live in tropical climates
  • people with weakened immune systems caused by factors such as organ transplants or cancer treatments
  • people who have atopic dermatitis, which is a common form of eczema that causes scaly and itchy rashes
  • people who participate in contact sports, such as wrestling or football, in which bare skin-to-skin contact is common

Because the skin bumps caused by molluscum contagiosum have a distinct appearance, your doctor often can diagnose the infection by merely looking at the affected area. A skin scraping or biopsy can confirm the diagnosis.

It’s usually unnecessary to treat molluscum contagiosum, but you should always have your doctor examine any skin lesions that last longer than a few days. A confirmed diagnosis of molluscum contagiosum will rule out other causes for the lesions, such as skin cancer, chickenpox, or warts.

In most cases, if you have a healthy immune system, it won’t be necessary to treat the lesions caused by molluscum contagiosum. The bumps will fade away without medical intervention.

However, some circumstances may justify treatment. You may be a candidate for treatment if:

  • your lesions are large and located on your face and neck
  • you have an existing skin disease such as atopic dermatitis
  • you have serious concerns about spreading the virus

The most effective treatments for molluscum contagiosum are performed by a doctor. These include cryotherapy, curettage, laser therapy, and topical therapy:

  • During cryotherapy, the doctor freezes each bump with liquid nitrogen.
  • During curettage, the doctor pierces the bump and scrapes it off the skin with a small tool.
  • During laser therapy, the doctor uses a laser to destroy each bump.
  • During topical therapy, the doctor applies creams containing acids or chemicals to the bumps to induce peeling of the top layers of the skin.

In some cases, these techniques can be painful and cause scarring. Anesthesia may also be necessary.

Since these methods involve treating each bump, a procedure may require more than one session. If you have many large bumps, additional treatment may be necessary every three to six weeks until the bumps disappear. New bumps may appear as the existing ones are treated.

In some cases, your doctor may prescribe the following medications:

  • trichloroacetic acid
  • topical podophyllotoxin cream (Condylox)
  • cantharidin (Cantharone), which is obtained from the blister beetle and applied by your doctor
  • imiquimod (Aldara)

If you’re pregnant, planning to become pregnant, or breastfeeding, let your doctor know about your condition before taking these medications or any others.

If your immune system is weakened by a disease such as HIV or by drugs such as those used for treating cancer, it may be necessary to treat molluscum contagiosum. Successful treatment is more difficult for people with weakened immune systems than it is for those with healthy immune systems.

Antiretroviral therapy is the most effective treatment for people with HIV if they contract molluscum contagiosum because it can work to strengthen the immune system to fight the virus.

It’s important to talk to your doctor before attempting any treatments for molluscum contagiosum.

A molluscum contagiosum infection will usually go away on its own if your immune system is healthy. Typically, this happens gradually within 6 to 12 months and without scarring. However, for some, it may take from a few months up to a few years for the bumps to disappear. The infection can be more persistent and last even longer for people with immune system problems.

Once the lesions fade, the M. contagiosum virus is no longer present in your body. When this happens, you can’t spread the virus to others or to other parts of your body. You’ll see more bumps only if you become infected again.

Unlike with chickenpox, if you’ve had molluscum contagiosum once, you’re not protected against being infected again.

The best way to prevent getting molluscum contagiosum is to avoid touching the skin of another person who has the infection. Following these suggestions can also help you prevent the spread of the infection:

  • Practice effective hand washing with warm water and soap.
  • Instruct children in proper hand-washing techniques since they’re more likely to use touch in play and interaction with others.
  • Avoid sharing personal items. This includes towels, clothing, hairbrushes, or bar soaps.
  • Avoid using shared sports gear that may have come in direct contact with someone else’s bare skin.
  • Avoid picking at or touching areas of your skin where the bumps exist.
  • Keep the bumps clean and covered to prevent yourself or others from touching them and spreading the virus.
  • Avoid shaving or using electrolysis where the bumps are located.
  • Avoid sexual contact if you have bumps in the genital area.