Molluscum contagiosum is a common and contagious viral skin infection. It causes raised, pearl-like nodules or papules on the skin.
These papules are called molluscum bodies, Mollusca, or condyloma subcutaneum. The condition is known as molluscipoxvirus.
Molluscum contagiosum virus (MCV) mostly affects children under the age of 15 years.
The papules are generally painless, and they do not itch. They can affect any area of skin, but especially the trunk of the body, arms, and legs. According to the Centers for Disease Control and Prevention (CDC), they mostly heal without intervention within 6 to 12 months, and they do not leave scars. In some cases, however, it may take up to 4 years to resolve.
No one knows how many people develop molluscum contagiosum because many people do not seek medical advice.
Treatment can stop MCV from spreading, but it is not generally necessary because the condition normally improves without intervention.
Image credit: Bray, D., 2011
Molluscum on the inner elbow
Image credit: Van Herk, E., 2005
Molluscum on child’s torso
Image credit: Eug, 2012
The MCV virus causes bumps on the skin.
For most people, symptoms only appear on the skin. After initial infection, it can take from 7 days to 6 months for symptoms to emerge.
The American Academy of Dermatology notes that it often takes 7 weeks for the bumps to appear.
The papules appear as small, firm, flesh-colored, dome-shaped, pearly, wart-like spots on the skin.
They are typically 1 to 5 millimeters (mm) in diameter with a dimpled center. These Mollusca tend to develop on any part of the skin that is not usually covered, such as the arms, face, and hands. They can also occur on the chest and stomach.
Sexually transmitted Mollusca generally appear on the genitalia, groin, lower abdomen, and inner thighs. They usually develop in small clusters and remain on the top layer of skin, but they can spread to other parts of the body.
Some Mollusca have a small white dot with pus, and they release a thick, white fluid when they burst. The dimpled part may bleed.
Most people will have up to 20 papules, but some may have over 100. If there are many, or if they are more than 5 mm across, medical advice should be sought because this may mean there is a problem with the immune system.
After about 6 to 12 weeks, the Mollusca will crust over and then heal. A tiny patch of lighter skin or a pitted mark may remain, but there will not usually be any scars.
For a year or more, new Mollusca may continue to form in other parts of the body as old ones crust over and heal. Once they disappear completely, they are highly unlikely to come back.
In rare cases, the Mollusca may persist for years.
MCV can spread through close, direct contact with an infected person, normally through skin-to-skin contact, for instance, via sexual activity. It can also spread to different parts of the body, and to other people if they touch contaminated objects, such as towels.
Most people are resistant to the virus, and they are unlikely to become infected unless their immune system is compromised.
The virus is contagious until the bumps are gone.
Among children, MCV is common, but because it is benign and self-limiting, there is no need to miss days of school.
Although anyone can get molluscum contagiosum, some people are more at risk, including:
- children under 10 years of age
- people in tropical climates
- people involved in contact sports where skin-on-skin contact is more common
- anyone with a weak immune system
- individuals with atopic dermatitis
Laser treatment is one option.
Medical advice is not always necessary, as the condition is self-limiting. If the individual has large lesions on the face or neck, an existing skin condition, or concerns about spreading the virus, treatment may be advised.
Treatment options include:
Curettage: This involves scraping the papule away using a curet, a spoon-shaped instrument with a sharp edge, possibly under local anesthetic.
Cryotherapy: This uses pressurized liquid spray to freeze the papule. Each lesion is frozen for up to 10 seconds, or until a layer of ice forms over the spot and surrounding skin. Sometimes several sessions are needed.
Diathermy: This uses a heated electrical device to burn off the Mollusca under a local anesthetic.
Laser therapy: This uses intense, narrow beams of light to treat MCV.
Chemical treatment: The doctor dips a sharp metal instrument into either podophyllin or phenol and then pricks each Mollusca. These eventually burst and empty out their contents. Chemical treatment can cause scarring and is said to be uncomfortable.
If dermatitis or eczema develops around the papules, the doctor may recommend a hydrocortisone cream, an ointment to relieve any itching, or a prescription topical steroid. These are applied to the areas of dermatitis and not to the papules.
Anyone with a weakened immune system will need specialist treatment, depending on the extent of the MCV and the reason for the weakened immune system.
MCV does not stay dormant in the body, and it does not reappear. When it is gone, it is unlikely to return, unless there is a new infection.
Although the papules are not usually painful or itchy, other conditions can develop.
Eczema can appear around the Mollusca in some cases, causing itching, swelling, and sometimes pain. Eczema can lead to scratching, and this can increase the risk of infection and spreading of the virus, as well as slowing down the healing process.
Picking or scratching the bumps can also lead to bacterial infection and itching. The doctor may prescribe antibiotics.
Complications are more likely to affect people with a weakened immune system. This can be because of HIV, chemotherapy, or the use of certain medications.
Scarring may remain as small patches of paler skin or tiny indents. If infection occurs, scarring is more likely.
Eye complications, such as conjunctivitis or keratitis, can occur if MCV is around the eyes. They will be referred to an eye specialist.
Washing hands thoroughly, especially after using the toilet or before cooking, is important for preventing MCV.
A number of precautions can help to stem the spread of MCV.
- Practice good hand hygiene, especially if there is someone with MCV in the household.
- Cover the Mollusca if there is a risk of other people having skin-to-skin contact.
- Avoid contact sports, such as judo, wrestling, or rugby.
- Do not touch, scratch, or rub the papules. After touching them, the individual should wash their hands at once with warm water and soap.
- Do not shave over affected areas of skin, because this can encourage the infection to spread.
- Do not share personal items, such as clothing, towels, flannels, and hairbrushes with a person who has MCV.
An adult with MCV should avoid physical contact until the Mollusca have completely gone. Condoms do not provide total protection from MCV spread, as the virus can pass between areas of skin that are not covered by a condom.
In swimming pools, MCV is most likely transmitted through items that are touched outside the pool, such as towels and diving boards, rather than in the chlorinated water. Papules should be covered with watertight bandages before swimming.
Overall, molluscum contagiosum is not a serious complaint. In general, it will disappear on its own within 6 to 12 months. However, as with any condition, measures should be taken to prevent spread. Also, if symptoms appear to be worsening, it is important to see a doctor.