Health Library Molluscum ContagiosumFrom Healthwise

What is molluscum contagiosum?

Molluscum contagiosum is a viral infection of the skin that causes small pearly or flesh-colored bumps. The bumps may be clear, and the center is often indented (umbilicated). The virus is easily spread (contagious) but is not harmful. However, in people with impaired immune systems, such as HIV infection, there may be a lot of bumps, which can be unattractive.

What are the symptoms?

The small, round, indented bumps are usually about 3 mm (0.1 in.) to 5 mm (0.2 in.) in size (a little smaller than a pencil eraser). The bumps are painless. They may appear alone or in groups. They are most often found on the trunk, face, eyelids or genital area. In children, bumps usually appear on the trunk, face, and arms. In sexually active teenagers and young adults, the bumps are usually located in the genital area.¹ The bumps may become inflamed and turn red as part of the body's natural immune system response as it fights the virus.

The incubation period—the time from exposure to the virus until the bumps appear—is usually 2 to 7 weeks but can be up to 6 months.²

In people who have an impaired immune system, such as HIV infection, symptoms of molluscum contagiosum are more severe.

How does molluscum contagiosum spread?

The virus commonly spreads through skin-to-skin contact. This includes sexual contact or touching or scratching the bumps and then touching the skin. Handling objects that have the virus on them, such as a towel, can also result in infection. The virus can spread from one part of the body to another or to other people. The virus can be spread among children at day care or at school. Molluscum contagiosum is contagious until the bumps are gone—which, if untreated, may be up to 6 months or longer.

Molluscum contagiosum in a child's genital area is common, usually because the child infects the area through scratching. However, if other factors are present, sexual abuse may be considered.

How is molluscum contagiosum diagnosed?

Molluscum contagiosum is usually diagnosed during a physical examination. If the diagnosis is unclear and other conditions are suspected, your health professional may take a sample of the bump to examine (biopsy). If an adult has bumps in his or her genital area, the health professional may check for other sexually transmitted diseases, such as genital herpes.

How is it treated?

In healthy people, treatment for molluscum contagiosum may not be necessary because individual bumps usually go away on their own in 2 to 4 months, although it may take longer. Some people choose to remove the bumps because they are embarrassed by them, or to keep them from spreading to other people. Health professionals usually recommend treating bumps located in the genital area to prevent them from spreading.

If needed, treatment choices include:

• Removing the viral material in the center by scraping the center briskly (curettage).
• Freezing the skin growth (cryotherapy).
• Putting medication on the skin (topical medication).
• Taking medication by mouth (oral medication).

Who is affected by molluscum contagiosum?

Molluscum contagiosum is most common in children. It is typically seen in children age 2 to 12.^{3, 4} In teens and young adults, molluscum contagiosum is primarily a sexually transmitted disease. However, it is also found among wrestlers, swimmers, gymnasts, masseurs, and people who use steam rooms and saunas.

Molluscum contagiosum is more common in warm, humid climates with crowded living conditions than in mild climates.

Frequently Asked Questions

Symptoms of molluscum contagiosum include bumps that are:

• Small, round, and often indented in the center.
• Usually pearly and flesh-colored. The bumps may be either clear or red and inflamed.
• Usually about 3 mm (0.1 in.) to 5 mm (0.2 in.) in size (a little smaller than a pencil eraser).
• Sometimes filled with a thick white material.
• Alone or in a group. They are often seen in groups (from a few to 20 or 30) in one or two areas.
• Most often found on the trunk, face, eyelids, or genital area in temperate climates and on extremities in the tropics. In children, bumps usually appear on the trunk, face, and arms. In sexually active adolescents and young adults, the bumps are usually located in the genital area.
• Sometimes itchy.
• Painless.

Bumps usually go away on their own in 2 to 4 months, although they may last longer.

Bumps may develop along with eczema, and you may not notice the bumps as much as the eczema.

Molluscum contagiosum in people who have an impaired immune system, such as HIV infection, can be more serious. The bumps are widespread and:

• Can be large—up to 15 mm (0.6 in.) in size.
• Appear in large numbers. For example, there can be 100 or more bumps on the face.
• Are aggravated by shaving.
• Do not usually go away on their own.
• Are hard to treat.
• Can mimic other serious diseases of people with HIV infection (such as deep fungal infection).

Conditions that may appear similar to molluscum contagiosum include warts, chickenpox, genital warts, basal cell skin cancer, and lichen planus.

Molluscum contagiosum is usually diagnosed during a physical examination. If you have bumps in your genital area, your health professional may check for other sexually transmitted diseases, such as genital herpes. Some health professionals may consider testing for human immunodeficiency virus (HIV) if you are at risk for the condition and you have bumps on your face or other symptoms of a severe case of molluscum contagiosum.

A biopsy may be done if the diagnosis is unclear and other conditions are suspected.

Treatment for molluscum contagiosum is not always necessary because most bumps will go away within 2 to 4 months, although they may last longer. However, if bumps are visible or embarrassing, or in order to prevent their spread, you may want them removed. Removal or other treatment is recommended for bumps in the genital area.

Treatment varies depending on your age and health and the location of the bumps. There has been little research on how well any of the treatments work, or how they compare to each other.⁵

Nonprescription treatment includes:

• Salicylic acid. You apply this nonprescription medication directly to the bumps. It is usually not painful and is often regarded as the first treatment to try.⁴

Self-administered prescription medication includes:

• Imiquimod, a form of immunotherapy. Immunotherapy triggers your immune system to fight the virus causing the skin growth. Imiquimod is applied 3 times per week, left on the skin for 6 to 10 hours, and washed off. A course may last from 4 to 16 weeks. Small studies have indicated that it is successful about 80% of the time.⁶
• Topical medications such as podofilox (Condylox) and tretinoin (Avita, Renova). These medications are put directly on the bumps. Podofilox is more often used in the treatment of genital warts.

Treatment by your health professional includes:

• Curettage. The viral material in the center of the bump is scraped out. A local or topical anesthetic can be used to numb the area. A small scraping instrument called a curette is used to quickly remove the bumps. This procedure is very effective and not too painful. It may cause scarring.
• Topical medications. Your health professional applies a chemical to the bumps. This destroys the top layers of the skin, allowing a new layer to form. When the chemical is applied, you may feel a burning sensation. Side effects may include mild scarring. How often and how long the chemical is applied will vary. Chemicals used include trichloroacetic acid, podophyllin resin, potassium hydroxide, and cantharidin. Trichloroacetic acid is often used in people with a weak immune system. Cantharidin causes the bumps to blister and go away. It may cause pain as the blister develops. Cantharidin is considered safe and effective.⁷
• Cryotherapy. The bump is frozen with liquid nitrogen. A local anesthetic may be used to numb the area. The liquid nitrogen is sprayed or applied with a cotton-tip applicator for 5 or more seconds. This procedure usually is not too painful, is not as likely as curettage to cause scarring, and usually is effective. More than one treatment is often necessary.
• Laser surgery. Bumps can be removed through laser surgery.

Treatment for children

Treatment is not always necessary for children because molluscum contagiosum usually goes away on its own. Whether to treat depends on many factors. For example, if a bump is near a child's eye, it may be treated to prevent conjunctivitis—or it may not be treated, to avoid possible eye damage. Pain caused by treatment and the potential for scarring are important considerations when deciding about treatment for children.

Although it is acceptable to leave molluscum contagiosum untreated, treatment helps to prevent the spread of the virus to other parts of the body or to other people.

Initial treatment options for children include cryotherapy, curettage, and topical medication.

Treatment in the genital area

Molluscum contagiosum in the genital area is often treated to prevent spreading through sexual activity. Common treatment procedures include cryotherapy, curettage, or imiquimod.

Treatment for people with other medical conditions

If you have molluscum contagiosum and an impaired immune system, treatment will usually be recommended to help prevent the spread and severity of the bumps, but they are often difficult to treat. The main treatment options are cryotherapy, curettage, oral medication, or topical medications. Treatments for widespread, difficult-to-treat cases include laser therapy and trichloroacetic acid.

Home treatment for molluscum contagiosum involves taking care of the bumps if they have been treated and preventing them from spreading to other parts of your body or to others.

If the bumps have been treated, it is important to keep the area clean and protected. Ask your health professional for specific instructions.

To prevent molluscum contagiosum from spreading:

• Try not to scratch. Put a piece of tape or a bandage over any bumps.
• Avoid contact sports, swimming pools, and shared baths and towels.
• If bumps are on the face, avoid shaving.
• If bumps are on the genital area, avoid sexual activity.

Organizations

• Genital Warts (Human Papillomavirus)
• Skin Cancer, Melanoma
• Skin Changes
• Warts and Plantar Warts

Citations

1. Landau JW (2002). Warts and molluscum contagiosum. In FD Burg et al., eds., Gellis and Kagan's Current Pediatric Therapy, pp. 873–874. Philadelphia: W.B. Saunders.

2. American Academy of Pediatrics (2003). Molluscum contagiosum. In LK Pickering, ed., Red Book: 2003 Report of the Committee on Infectious Diseases, 26th ed., pp. 437–438. Elk Grove Village, IL: American Academy of Pediatrics.

3. Braue A, et al. (2005). Epidemiology and impact of childhood molluscum contagiosum: A case series and critical review of the literature. Pediatric Dermatology, 22(4): 287–294.

4. Sladden MJ, Johnston GA (2004). Common skin infections in children. BMJ, 329(7457): 95–99.

5. Stulberg DL, Hutchinson AG (2003). Molluscum contagiosum and warts. American Family Physician, 67(6): 1233–1240.

6. Tyring SK (2003). Molluscum contagiosum: The importance of early diagnosis and treatment. American Journal of Obstetrics and Gynecology, 189(3 Suppl): S12–S16.

7. Habif TP (2004). Molluscum contagiosum. In Clinical Dermatology: A Color Guide to Diagnosis and Therapy, 4th ed., pp. 344–345. Philadelphia: Mosby.

Other Works Consulted

• Lowy DR, Androphy EJ (2003). Molluscum contagiosum. In IM Freedberg et al., eds., Fitzpatrick's Dermatology in General Medicine, 6th ed., vol. 2, pp. 2114–2117. New York: McGraw-Hill.

Author:	Robin Parks, MS	Last Updated: January 12, 2007
Medical Review:	Patrice Burgess, MD - Family Medicine Adam Husney, MD - Family Medicine Alexander H. Murray, MD, FRCPC - Dermatology
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