Molluscum contagiosum: What is it? Causes, Symptoms, Diagnosis and Treatment


It is due to a poxvirus infection of the skin.

It is a benign infection of spontaneous and painless resolution that lasts for months and occasionally up to two years.

It is common in young children, where injuries occur anywhere on the body, including the genitals, especially in the folds of the skin.

In adults, it can be seen as a sexually acquired infection that affects the genitals, the pubic region, the lower abdomen, the upper part of the thighs and the buttocks.

In HIV infection and other immunosuppressive conditions, the lesions can be generalized and atypical.

Those patients with atopic dermatitis can also have disseminated molluscum.


Molluscum contagiosum is an infection caused by the Molluscipoxvirus virus that is a member of the smallpox virus family (Poxviridae).

This disease is transmitted due to direct contact with the skin of another infected person.


Molluscum contagiosum causes a small number of protuberances or raised dome-shaped nodules on the skin.

They are usually very small and have a pink or skin-colored color, bright and with a small hole in the center.

They occur more often on the face, but can develop anywhere on the body, except for the palms of the hands and the soles of the feet.

They are usually painless and can last from a few months to a few years.

Usually the incubation period lasts from 2 to 7 weeks, although it could eventually be longer, and may last up to a few months.


The doctor can usually make the diagnosis through a clinical examination of the lesions.

In case the diagnosis is not clear, the doctor may request a biopsy of the skin lesions.

The lesions are usually multiple and occur in groups, which present as firm papules, dome-shaped, smooth surface and central umbilication.

They are found in the keratinized skin, especially in the folds of the skin and in areas where there is hair, and can affect almost any part of the body.

The genital mollusc can be confused with ectopic sebaceous glands and patients can confuse lesions with genital warts.

Localized redness and pain may be due to a secondary bacterial infection.

Redness also occurs before natural resolution.

Approximately 10% of adults develop eczema around the lesions that resolves as the lesions recede.


The treatment is mainly for aesthetic reasons. Patients should be warned about the risks of autoinoculation and are advised not to shave or depilate the genital regions, to avoid further dissemination of lesions, secondary infections and scarring.

Frequently, it can be seen that the mollusk nodules disappear without any treatment.

This means that in children with only one or a few injuries, which are widely disseminated, no special care is necessary.

Among the treatments for the elimination of molluscs, can be cited as the most used:

  • The procedure of stepping with local anesthesia or curette, are destructive, but very aggressive treatments that can cause bleeding and scarring and are rarely performed due to pain problems and possible scarring.
  • Through the use of therapies with agents used to perform the chemical peel such as: 1% topical Cantaridine, potassium hydroxide at different concentrations, 3% podophyllin and trichloroacetic acid.
  • Cryotherapy with the use of liquid nitrogen, in this treatment liquid nitrogen is applied with cryospray until an ice halo surrounds the lesion. This treatment can be repeated weekly until resolution. This procedure is usually painful and causes residual pigmentations.

The use of medications such as: Cidofovir 0.3 to 3% gel or cream, applied once a day for 15 days, Imiquimod 5% cream applied moderately three times a week for sixteen weeks and Cimetidine in a dose of 40mg per kg of weight per day, 0.5% podophyllotoxin cream or paint twice a day for 3 days for 4 weeks. Podophyllotoxin and Imiquimod should be avoided during pregnancy and lactation.

Some treatments may shorten the course of the disease, but this should be balanced with possible side effects.

Other treatments induce local epidermal inflammation and several treatments can leave scars.

Molluscum infection resolves naturally, usually does not leave long-term sequelae, and therefore it is important that any therapy chosen be mild and have minimal side effects.