Bumps. Most parents become very concerned when they see any type of skin lesion on their child. However, due to their developing immune systems, kids are prone to developing a few very common skin infections that manifest themselves in the form of one or many skin bumps. One more easily recognized problem is warts. Most people can spot these very easily, and while multiple OTC remedies and medical therapies exist for these troublesome lesions, they can be quite frustrating to get rid of!
Another less commonly known, but just as prevalent eruption in kids is molluscum contagiosum. They are much less easily recognized and become quite numerous very quickly prompting a call to your family pediatrician or dermatologist.
Ranging in size from pinpoint to several millimeters, these lesions are caused by the molluscum contagiosum virus (MCV). MCV is a member of the Molluscipox genus of the Poxviridae family. There are two subtypes of this virus, MCV I and MCV II, but either subtype causes almost identical looking bumps on the skin. The lesions of MCV infection are usually pink, smooth, dome-shaped bumps. In the center of each, a small umbilication or “belly button” may or may not be seen.
When present in children, the infection can become very widespread. Usually starting in the body fold areas (like the underarm or crease of the elbow), frequent skin on skin contact “auto-innoculates” or infects the surrounding skin, spreading the infection very quickly. While the bumps may be numerous, they tend not to itch or hurt. 
The good news is MCV infection is usually self limited; the bad news is it may be present for a year or more with successive crops of lesions erupting every few weeks. Eventually, the child’s immune system will detect and fight the virus. When this happens, one or more of the lesions will look “infected” becoming red, swollen and tender. Eventually, the lesions begin to crust over and/or will just disappear.
When diagnosed in adults, the infection tends to be in the groin and is considered an STD. It is completely treatable and curable, but further testing for other STDs may be warranted. If an adult has a widespread eruption of MCV, causes of immune system dysfunction should be sought, such as HIV infection.
The virus is spread from person to person via skin on skin contact. So siblings should probably limit close physical play and may want to bathe separately. Although MCV infection is self limited, treatments are available and generally effective. One readily available option at the doctor’s office is liquid nitrogen cryotherapy. While a little uncomfortable, most children and adults will tolerate “freezing” each individual bump which causes it to blister slightly, scab and then heal. Several rounds of treatment may be needed as the lesions tend to spread easily and come in crops as noted above. Another destructive method of treatment is Cantharidin or cantharone. This liquid is derived from a “blister beetle” and when placed on the individual bumps will induce a contact dermatitis, similar to poison ivy, which then causes a blister with subsequent scabbing and healing. While some dermatologists still use this therapy, many do not as it has been taken of the market in the United States by the FDA due to concerns of severe blistering reactions to it. Some providers will curettage or “scrape” the individual bumps off the skin. While very effective, this treatment has the potential for unwanted scarring. There are a couple of prescription topical therapies for at home use that show promise for success. Unfortunately, no oral medications have been developed to treat MCV.
While worrisome in appearance, MCV infection is quite common, painless and generally benign. Most pediatricians will recommend a watch and wait approach. When lesions become extensive, or parents are very concerned, a visit to your dermatology provider can help sort out all treatment options and decide the best one for your child.
