What is Molluscum Contagiosum?
Molluscum contagiosum is a common skin infection in children, with an increasing incidence. It causes bumps that are flesh colored with a dimple or white “plug” on the top. The bumps are small, about 2-5 millimeters in diameter (occasionally larger). They can become red and inflamed, especially as the body begins to fight off the virus or if it becomes secondarily infected with bacteria.
What do they look like?
This is a picture taken from a phone, but there are many high quality pictures on DermNetNZ .
What does it feel like?
The rash usually does not itch, hurt, or cause other symptoms, but may bother kids due to location on the body or if they do not like the physical appearance of them. Treatment is recommended only if the child is bothered by the wart, since they generally do not cause other problems and treatments may not be tolerated by the child.
Is this common?
Molluscum is very common in young children but generally harmless other than irritation if it is in an area that gets rubbed frequently, such as on the inner thigh.
What Causes Molluscum Contagiosum?
Molluscum is caused by the molluscum contagiosum virus, from the poxvirus family.
It is spread through direct skin to skin contact and contact with contaminated objects or from warm water (such as bathing together or using a hot tub).
The incubation period is 2-6 weeks.
It can spread from person to person and from one part of a person to another part on the same body by direct contact or rubbing. It can also be spread through warm water (bathing or hot tubs).
It can infect any skin and sometimes mucus membranes (lips, eyelid). If the lesions are on the eyelid an ophthalmologist needs to be involved in treatment.
What can prevent the spread of the virus?
- Avoid touching, rubbing or scratching the bumps.
- Don't share your clothing, towels, hairbrushes, razors or other personal items.
- Cover the lesions with bandaides, especially if contact with another person is anticipated, such as during contact sports.
What is the Treatment?
Treatment for molluscum is not always needed. Molluscum contagiosum is self resolving if given time (6 months to 3 years).
There are also many treatment options with some benefit. Do not attempt treating lesions on the genitals, eyelids or near the eyes at home. These are best treated professionally.
These warts may lead to scarring, regardless of treatment type.
Molluscum often looks infected before resolution. This is referred to as BOTE, the "Beginning Of The End ." Many kids are prescribed antibiotics unnecessarily at this time. Unless there are other signs of infection, such as fever, it is okay to watch the area without antibiotics.
The most common treatments involve either physically destroying the lesions or by boosting the body's immune response against the virus.
- "Popping” the lesions can remove the central core. It can lead to spread of the virus, so must be done cautiously. It may lead to scarring. We do NOT recommend this.
- Duct tape method: Cover the lesions with duct tape overnight and remove it in the morning for several weeks. This is a well-tolerated treatment by many children (except in areas with too much hair). This irritates the wart virus and helps remove the plug without spreading the virus as easily as popping might. We do recommend this option for those who tolerate the tape.
- Apply a small amount of cider vinegar to each lesion with a cotton tipped swab (ie Qtip) once daily. This may be combined with the duct tape method. Some people believe this works because vinegar is acidic, but studies have not been done. Since these bumps are known to self-resolve, we do not know if this is a beneficial treatment or if people see the bumps go away because they would have anyway unless studies are done.
- Freeze with liquid nitrogen, but this is often not well tolerated due to pain. This might also induce scarring. We do not recommend this.
- Cantharidin (aka beetle juice) can be applied to each wart in our office, up to 30 at a time. This causes a blister to form, destroying the wart. It can cause pain when the blister forms but is generally more tolerated than freezing. Scarring may occur. It cannot be done on the face, genitals, or between the buttocks. Check with your insurance company to see if they cover wart treatments. We use the CPT code 17110, destruction of warts (up to 14), or 17111 (for 15+).
- Prescription creams that stimulate the immune response work for many of these warts, can be used on the face or genitalia/buttocks, and are generally well tolerated by children. The downside is high cost for most prescription plans.
- Acne medications have been used by patients when they misdiagnose these bumps as acne, and some have reported that it works. These are generally inexpensive, available over the counter, and well tolerated. They would be considered "off label" use because they have not been studied for this purpose. They can be applied to the bumps overnight and washed off in the morning. You can combine this with duct tape. This may take weeks to months to be effective. (But remember the lesions may simply go away in this time frame, and without studies we do not know if these work faster.)
- Tretinoin can be applied several nights per week for a few months.
- Benzoyl peroxide can be applied to the areas several nights per week for several months. Remember that Benzoyl peroxide can bleach the clothes, so wear overnight with a white shirt and wash off in the morning! You may also cover it with duct tape overnight.
- The oral medicine cimetidine has been used for treatment of molluscum in small children. This medicine is available in liquid form only by prescription but is over the counter for those who swallow pills. As with all medications, cimetidine may cause mild side effects, but is generally well tolerated and is taken twice daily for 2 months.
Adapted from the CDC's website
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- Cantharidin is the only FDA approved treatment of molluscum. It is a topical chemical treatment approved for use in adults and children ages 2 and older and must be administered by a health care professional.
- Oral cimetidine has been used as an alternative treatment for small children who are either afraid of the pain associated with cryotherapy, curettage, and laser therapy or because the possibility of scarring is to be avoided. While cimetidine is safe, painless, and well tolerated, facial mollusca do not respond as well as lesions elsewhere on the body.
- Podophyllotoxin cream (0.5%) is reliable as a home therapy for adults but is not recommended for pregnant women because of presumed toxicity to the fetus. Each lesion must be treated individually as the therapeutic effect is localized.
- Other options for topical therapy include iodine and salicylic acid, potassium hydroxide, tretinoin, and imiquimod (T cell modifier). These treatments must be prescribed by a health care professional.
Although molluscum contagiosum is annoying, easily spread, and sometimes uncomfortable, it does not cause serious disease in most children. No treatment is 100% effective, and many children simply prefer to have the rash rather than the treatments. It is okay to leave these untreated and they will go away over time- 6 months to 3 years.
