Skin rashes

The skin is frequently the gateway to diagnosis. Many visits to my office are for evaluation of a rash. So here are a few common ones to know about.

Roseola: This is a common viral infection, mostly children under 2 years of age. The child has a high fever off and on for several days (often very high, 104 degrees). Usually around day 3 or 4 the fever suddenly goes away and the child breaks out in a reddish spotty rash on the body, arms, legs, and even face. The rash signals the end of the illness, although the child is usually still crabby for another day or two. The illness is contagious mainly in the early part when fever is present and not contagious once the rash has broken out.  Treatment is conservative, fever management, hydration, support. Usually this is a one-time illness.

Hand/Foot/and Mouth disease: This is an illness caused by a virus called Coxsackie A16 (named after a town in upstate New York). The illness usually includes fever and the rash appears like little blisters on the hands, feet, and in the throat (if you can get a look in there). In younger children the rash is prominent in the diaper area and legs as well.  Again, being a viral infection, treatment is conservative. Contagion decreases as the child feels better and the fever and rash goes away.

Scarlet Fever: Yes, there is still scarlet fever around. Scarlet fever is an illness caused by a strep throat infection. This particular strain of strep produces a toxin which produces a characteristic rash. The rash is a fine red sandpaper rash, especially in the armpits and the groin area, but also on the body, but not on the face. Children with scarlet fever often complain of headache and stomach-ache as well. In the pre-antibiotic era there were strains of strep which caused very serious and dangerous illness, but in the modern era this illness is generally not serious. It is a bacterial infection and can be treated with antibiotics. The rash goes away with treatment, usually it lasts about a week.

Chicken Pox: Although we have been vaccinating against chicken pox since 1995, there are still many cases around. Chicken pox is a classic childhood illness. It is a respiratory virus, so before the rash breaks out, typically a child has a cold, cough, and perhaps some fever. The rash is actually small individual bumps, starting up around the head and neck (they are usually in the scalp) and progressing over many days to the rest of the body. Some of the bumps will actually look like a blister with clear fluid inside sitting on a little red base. They are itchy and they gradually scab over as the days go by. The incubation period is 10-21 days (the time between being exposed to the virus and the day the illness starts). Treatment is conservative (fever management, and for the itching use colloidal oatmeal bath/Aveeno, Bendadryl liquid or pills when appropriate).

Fifth’s Disease: This is a fairly common viral infection, mainly in school age children.  There is usually little if any fever. The rash starts on the face and cheeks--it is sometimes called slapped-cheek disease from its appearance. The rash progresses onto the arms and legs and to a lesser extent the body. On the arms and legs it has a lacy serpent like appearance. It is generally a mild illness with minimal itchiness, and the rash last a couple of weeks. It is caused by a human parvovirus. That may be of importance because if a pregnant woman gets infected with this virus in her first trimester the baby can be injured by this virus. Once again, treatment is conservative.

Eczema: This is the most common rash I see every day. Eczema is a dry, itchy, scaly rash, most common in the front of the elbow, behind the knee, around the wrists and ankles, but it can occur anywhere. It is very common in babies. In many children it may represent a sign of allergy as it is sometimes called atopic or allergic dermatitis. One common feature in eczema is the tendency of the skin to dry out and dehydrate, so moisturizing lotions are often very helpful. We prescribe a variety of cortisone type creams and ointments for this condition as well. Diet may play a role on occasion. Eczema can make a child very uncomfortable.

Hives: Hives or urticaria are another very common skin problem, and very often they are a sign of some type of allergic reaction. Hives are a raised, welt-like rash. They can be very small or can be large areas of raised welted skin. They are usually very itchy.  Hives represent activity underneath the skin in the blood vessels, so creams and ointments aren’t usually helpful, and more likely you will need something like Benadryl by mouth to relieve the itching or on occasion you may need systemic cortisone. Although allergy to a food or substance may cause some cases of hives, the majority of hives in children are likely caused by a viral infection.