Molluscum Contagiosum

What Is Molluscum Contagiosum?

Molluscum contagiosum (MC) is a common skin infection caused by a virus. It occurs worldwide and primarily affects children and young adults. The skin lesions characteristically appear as raised, rounded bumps that are white, pink, or flesh-colored. Transmission of the virus occurs by direct person-to-person contact or via contact with infected objects. It is frequently diagnosed by a health-care provider based on its characteristic appearance, although testing may be needed in cases of uncertainty. MC is a benign, self-limited infection in healthy individuals, and treatment is not always required. However, certain people (for example, those with weakened immune systems) frequently require treatment as the skin lesions may be more persistent and widespread. Maintaining good personal hygiene and avoiding direct contact with infected individuals can help prevent this viral skin infection. MC generally carries an excellent prognosis.

What Is the Cause of Molluscum Contagiosum?

Molluscum contagiosum is caused by the molluscum contagiosum virus (MCV), a member of the poxvirus family. Four types (I-IV) of molluscum contagiosum virus have been identified, with MCV-I being the most common cause of infection. Humans are the only known reservoir for this virus. The molluscum contagiosum virus occurs worldwide, but it is more common in developing countries, especially those in the tropics. It is estimated to account for 1% of all skin disorders diagnosed in the United States. Molluscum contagiosum infection is most common in children and young adults, with males being affected more commonly than females. It is most common in children 1 to 10 years of age. Individuals with weakened immune systems (immunocompromised), such as those with AIDS, also have a higher incidence of infection. Atopic dermatitis is also thought to be a risk factor for the development of molluscum contagiosum.

Adult Skin Problems: Recognize These Skin Conditions?

What Is the Incubation Period for Molluscum Contagiosum?

The development of the skin lesions after the initial exposure to the virus (incubation period) typically occurs between two to seven weeks, though it may take up to six months in some individuals.

Is Molluscum Contagiosum Contagious?

Yes, molluscum contagiosum is contagious. Molluscum contagiosum is transmitted by either direct person-to-person contact or through contact with contaminated objects, such as shared clothing, towels, washcloths, and toys. This route of transmission is most common in children. In adults, molluscum contagiosum is often acquired through sexual contact. Molluscum contagiosum has also been reported to spread between individuals using the same gym equipment. Furthermore, if an infected person touches the lesions and then touches another part of his or her body, it can cause spread to that area (known as autoinoculation). If the face is involved, shaving may cause it to spread.

Outbreaks have been reported in

  • swimming pools, saunas, and steam baths,
  • wrestling matches,
  • during surgery, by a surgeon with a hand lesion (sore), and
  • getting tattoos (rare).

How Long Is Molluscum Contagiosum Contagious?

Molluscum contagiosum is contagious until all of the skin lesions have disappeared. Because the virus affects only the top layer of the skin, once the lesions have gone away completely, it is not possible to transmit the virus to others. Unlike the herpes virus, molluscum contagiosum does not remain dormant in your body once the rash has disappeared.

What Are Symptoms and Signs of Molluscum Contagiosum?

The molluscum contagiosum rash begins as tiny painless papules (small raised bumps), each measuring about 2-5 mm in diameter.

  • The lesions typically appear as dome-shaped papules that have a waxy, smooth, or pearly surface. They are either white, pink or flesh-colored, and with time, the center develops a dimple (umbilication), which can contain a white, cheesy substance. This core may be squeezed out easily. There may be redness and scaling at the edges of a lesion from inflammation or from scratching.
  • Lesions may be located on almost any area of the skin. They are usually grouped in one or two areas, but they may be widely spread as well. In children, they commonly occur on the face, trunk, and limbs. Adults often get lesions on the genital area, the lower abdomen, the buttocks, and the inner thigh. Usually, fewer than 20 lesions appear, but several hundred are possible.
  • The lesions do not affect the palms or soles and only rarely affect the mucous membranes of the mouth.
  • Usually, there is no itching or tenderness, and there are no generalized symptoms such as fever, nausea, or weakness.
  • People with weakened immune systems can develop widespread large lesions that can be persistent and rapidly spreading. These lesions often appear on the face, and they can come together (coalesce) to form giant lesions. Individuals with a weakened immune system include patients with AIDS, cancer, or those taking medications such as steroids or those undergoing cancer chemotherapy that cause impairment of the body's defense mechanisms.
  • Though cases of severe molluscum contagiosum may indicate underlying infection with the HIV virus, the vast majority of people who develop molluscum contagiosum have no such serious underlying medical problem.

Skin Rashes, Bumps, and Lumps

See pictures of common skin problems, such as ingrown hairs, cysts, warts, molluscum contagiosum, and folliculitis. Plus, get tips on treatment of these various skin conditions.

When Should Someone Seek Medical Care for Molluscum Contagiosum?

  • See your health-care professional if you develop a rash suggestive of molluscum contagiosum in order to confirm the diagnosis and to discuss treatment options, if deemed necessary.
  • Sometimes the lesions can become irritated, inflamed, and secondarily infected by bacteria. If this occurs, consult a health-care professional to discuss the need for antibiotics.
  • Lesions involving the eyelids may be associated with conjunctivitis (pinkeye) and require special treatment.

What Specialists Treat Molluscum Contagiosum?

Molluscum contagiosum can generally be diagnosed and treated by your primary-care physician, such as a family physician, internist, or pediatrician. In select cases, a dermatologist or infectious-disease specialist may be consulted.

What Exams and Tests Diagnose Molluscum Contagiosum?

  • Your health-care professional can usually diagnose molluscum contagiosum based solely on its distinctive appearance. In the majority of cases, no testing is necessary.
  • If the diagnosis is uncertain or in certain cases involving individuals with a weakened immune system, a skin biopsy may be performed by your health-care professional to confirm the diagnosis. Characteristic "molluscum bodies" will be seen under the microscope in the affected skin.
  • Conditions that can mimic molluscum contagiosum include some skin cancers, warts, and other skin infections.
Adult Skin Problems: Recognize These Skin Conditions?

What Are Home Remedies for Molluscum Contagiosum?

In healthy individuals, molluscum contagiosum is a benign, self-limiting condition that will typically resolve spontaneously on its own with expectant management. It can take anywhere between six to 12 months for the lesions to disappear on their own, though in rare cases it can take up to four years. Once the diagnosis of molluscum contagiosum is made, initial treatment measures at home should be directed at preventing the spread of the virus to other individuals. Also, scratching the lesions should be avoided to prevent the spread of the virus to other parts of the body and to prevent potential secondary bacterial skin infections.

What Are Treatments for Molluscum Contagiosum?

Treatment for molluscum contagiosum is not always necessary, as the lesions typically disappear and heal without scarring in healthy individuals. Especially in young children, the decision to treat a minor self-limiting condition must be weighed against the potential physical pain and psychological hardship associated with some treatment procedures. However, in certain clinical situations, treatment for molluscum contagiosum may be considered and undertaken. The different treatment options, as well as the associated risks and benefits, should be discussed with your health-care professional. They will recommend the most effective treatment approach based on your age, the location and number of lesions, and the presence of any underlying medical problems. In general, treatment is aimed at preventing transmission and autoinoculation, and some individuals also elect to undergo treatment because of cosmetic concerns or for persistent lesions. Those individuals with a weakened immune system often do not have an extremely effective response to therapy, and a long-term response is often difficult to achieve.

There are several different treatment options available for molluscum contagiosum. Some procedures may require multiple treatments and multiple office visits, and the potential side effects will vary with the procedure, but may include pain, skin irritation, blistering, skin pigmentation changes, and scarring. The following procedures can be performed in the office by your health-care professional:

  • Curettage: the use of a small instrument to scrape and remove the lesions from the skin
  • Cryotherapy: the use of liquid nitrogen to freeze and eliminate the lesions

What Medications Treat Molluscum Contagiosum?

There are a variety of topical medications that can be used to treat molluscum contagiosum. The particular agent chosen will depend on various factors. Your health-care professional may use any of the following topical agents, which are applied directly to the lesions:

  • Trichloroacetic acid
  • Salicylic acid
  • Potassium hydroxide
  • Tretinoin cream
  • Cantharidin
  • Imiquimod cream

Cimetidine, the anti-ulcer and anti-heartburn oral medication, has been used in younger children for the treatment of molluscum contagiosum as an alternative to other more potentially painful therapies. Its overall effectiveness has been questioned.

As previously noted, patients with weakened immune systems can be difficult and challenging to treat, and complete resolution of the skin lesions is often not possible. In addition to some of the treatments outlined above, various antiviral agents, such a cidofovir, ritonavir, and zidovudine, have been used with some success to treat severe molluscum contagiosum in some immunocompromised patients. For patients with AIDS, the most effective results are often achieved after the initiation of medications that target the HIV virus and boost the body's immune system.

How Can Someone Prevent Molluscum Contagiosum?

  • Because it can be spread by direct person-to-person contact, try to avoid direct skin contact with others who are infected. Affected individuals should cover the exposed lesions with clothing or a bandage to reduce the chance of transmission. It is not necessary to keep infected children out of school.
  • Avoid sharing personal items such as towels, washcloths, clothing, and razors. Avoiding contact with potentially infected objects such as gym equipment, mats, and benches is also recommended.
  • Because the rash can spread by autoinoculation (spread from one part of the body to another by touching the lesions), avoid scratching or picking at the lesions.
  • Because sexual transmission is common in adults, avoid sexual contact with infected people. Condoms may not be entirely effective in preventing the disease, as lesions may be on areas of skin not protected by condoms.

What Is the Prognosis for Molluscum Contagiosum?

The overall prognosis is excellent, as molluscum contagiosum is a self-limiting condition and spontaneous resolution is the rule for individuals who have intact immune systems. However, in immunocompromised individuals, the skin lesions can be much more persistent, widespread, and difficult to eradicate.

  • Individual lesions typically completely resolve within six to 12 months in healthy individuals, though they can sometimes be present for up to four years. In certain immunocompromised individuals, the lesions sometimes never resolve completely.
  • The development of new lesions by autoinoculation is common.
  • Some people may experience scarring, either from scratching, abrasion of the lesions, or from undergoing procedures to remove the lesions.
  • Secondary bacterial infection of the skin lesions is possible.
  • Even if you've had molluscum contagiosum previously, reinfection is still possible.
  • There is currently no vaccine available for molluscum contagiosum.
Adult Skin Problems: Recognize These Skin Conditions?

For More Information on Molluscum Contagiosum

Centers for Disease Control and Prevention, "Molluscum Contagiosum"
http://www.cdc.gov/poxvirus/molluscum-contagiosum/index.html

American Academy of Dermatology, "Molluscum Contagiosum"
https://www.aad.org/public/diseases/
contagious-skin-diseases/molluscum-contagiosum

Molluscum Contagiosum Pictures

Molluscum contagiosum consists of multiple smooth, pearly to flesh-colored lesions, each several millimeters in diameter. Note that some can become inflamed. Photo courtesy F. Fehl III, MD.
Molluscum contagiosum consists of multiple smooth, pearly to flesh-colored lesions, each several millimeters in diameter. Note that some can become inflamed. Photo courtesy F. Fehl III, MD.

A closer view demonstrates the central indentation that develops in the middle of the lesions with a white curdlike core. Photo courtesy F. Fehl III, MD.
A closer view demonstrates the central indentation that develops in the middle of the lesions with a white curdlike core. Photo courtesy F. Fehl III, MD.

The rash of molluscum contagiosum may be located on any area of the skin, including (as shown here) the face and neck. Photo courtesy F. Fehl III, MD.
The rash of molluscum contagiosum may be located on any area of the skin, including (as shown here) the face and neck. Photo courtesy F. Fehl III, MD.

Reviewed on 8/31/2017

REFERENCES:

American Academy of Dermatology. "Molluscum contagiosum." <https://www.aad.org/public/diseases/contagious-skin-diseases/molluscum-contagiosum>.

United States. Centers for Disease Control and Prevention. "Molluscum (Molluscum Contagiosum)." May 2015. <http://www.cdc.gov/poxvirus/molluscum-contagiosum/index.html>.

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