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Viral Exanthem

What is Viral Exanthem

Doctors use the term “viral exanthem” for any one of a number of common rashes that children can get when they have infections with certain viruses. Measles and chicken pox are examples of what used to be the best-known viral rashes. Fortunately, both of these fairly serious diseases, along with German measles, are mostly history because of vaccines. Today, the diagnosis of a “viral exanthem” usually means just that your doctor recognizes that your child’s rash is the result of infection with a common and usually harmless virus.

Viral rashes can have many different appearances. Very often they are just a widespread, red rash with tiny raised bumps almost like goose bumps. Sometimes they look like mosquito bites or other larger, red bumps on the skin. Some viral rashes itch, while others don’t seem to bother the child at all. In most (but not all) cases, children will have other signs of viral infection, such as a fever, runny nose, sore throat, or cough. A few kinds of viral rashes have very specific appearances. For example, in “Fifth Disease,” a young child may develop bright red cheeks. In “Roseola” children can develop a bright red rash over much of their body about a day after an unusually high fever. In “hand, foot, and mouth” disease, children get tiny red bumps on their palms, soles, and in the back of their throats. You can read our Aftercare Instruction on Hand, Foot, and Mouth disease. In most cases, though, we never find out which kind of virus caused a rash. The good news about all the viral rashes is that they go away on their own, without any specific treatment.

What is the biggest concern?

Most parents’ biggest concern is their child’s appearance and comfort. Viral rashes on the face can be frightening to parents, and they often wonder if the rash is a sign of something more serious. Doctors are usually mainly concerned to be sure that the rash isn’t a sign of a more serious condition. Your doctor can usually rule out serious problems just by examining your child and listening to your description of the illness. If your doctor develops concerns about something more serious going on, s/he may want to do some blood tests. Most of the time, however, doctors choose to wait a few days before doing much testing, because most viral rashes just go away on their own.

Viral Exanthem Treatment

Like most diseases that viruses cause, doctors don’t have any particular medicine that will make a viral rash go away faster. In fact, there are a few viral rashes that can get markedly worse if the child takes antibiotics. Your doctor will probably simply want you to watch your child over the next few days. The most likely result is that the rash will clear up on its own, and that will be the end of it.

Skin lotions, creams, and salves do not help with viral rashes. Some children like to get a lukewarm bath, especially if they have itching skin. Please try to avoid using harsh, adult soaps with fragrances or deodorant. These can damage children’s skin. You can also give your child diphenhydramine (dye-fen-hi-drah-meen; Benadryl® and many others) for itching. The main side effect of diphenhydramine is drowsiness, which is actually often helpful to a child whose itching is making him or her frantic.

You can use acetaminophen (Tylenol®) or ibuprofen (Advil® or Motrin®) to control fever in children over 3 months. Check with your doctor about using it in younger babies. Fever is not dangerous, but it can make the child uncomfortable. If your child seems comfortable there is no reason to give any medication just for fever. Please read our Aftercare Instructions about Fever.

When should I be worried?

Viral rashes are not dangerous. Very rarely the viruses that cause them can produce more serious conditions. Sometimes, what seemed at first to be a viral rash turns out to be a different skin rash. Here are some things to watch for while you are waiting for the rash to improve:

  • Continued high fever for more than 48 hours after the rash develops
  • New complaints such as headache, stiff neck, or abdominal pain
  • A worsening cough or difficulty breathing
  • Large circular marks or marks that look like “targets” on the skin
  • Bumps or wheals that appear like “hives,” with a purplish color
  • Aching or swollen joints
  • Red eyes
  • Sores in the mouth, on the tongue, or on the gums
  • A flat red or purplish rash that does not blanch (lose its color) when you press on it
  • Extreme fussiness or irritability, or lethargy (too sleepy)

If any of these occur, please be sure to call your doctor’s office right away. If your child has any of the items listed above in bold print, please go directly to the emergency room.

Other points of concern

By the time the rash appears on your child’s body, s/he has already probably spread the virus to other children. Not all children who get a viral infection will develop a rash. Your doctor will advise you about how long you should keep your child home from school or daycare.

In very rare cases the virus that caused the rash can cause serious effects days or weeks after the rash is gone. Some of the summer time viruses can cause a mild form of meningitis (inflammation of the brain and spinal cord coverings). This “viral meningitis” is not dangerous, but it is very painful, and it is important to be sure it is not the more dangerous meningitis from a bacterial infection. Signs of meningitis include a severe headache, stiff neck, discomfort in bright light, and vomiting, along with high fever.

In even rarer cases, the virus can cause the child’s immune system to damage the heart muscle. This condition, called “myocarditis,” may develop up to three weeks after the rash is gone. Symptoms of myocarditis include chest pain, difficulty breathing, extreme tiredness, and often a persistent cough, all lasting for more than a day or two, and all getting worse with time. Myocarditis is a very rare complication of viral infections.

Other Conditions that Might Be Present with Viral Exanthem

There are a few more serious conditions that can start out looking like viral rashes. It is usually clear within about 72 hours that something unusual is happening, however. Here are brief descriptions of a few of these conditions:

  • Infection with the bacterial germ called N. meningitidis can cause a high fever, severe headache, and a rash that starts off like tiny, flat red marks that don’t change color when pressed. The rash often spreads rapidly and turns dark purple. Children with this infection can become gravely ill within hours. Rapid treatment with antibiotics is life-saving. This condition is most common in toddlers and teens, but it is still very rare. A new vaccine came out in 2005 that may help to prevent this disease.
  • Rocky Mountain Spotted Fever causes tiny red spots on the palms and soles, and occasionally elsewhere. People with Rocky Mountain Spotted Fever also have severe headaches and often abdominal pain. This disease is the result of a bite from a tick that carries the infecting germ. The treatment is antibiotics.
  • Kawasaki Syndrome is a condition in younger children that includes a skin rash, red eyes, mouth sores or swollen tongue, swollen glands in the neck, and/or firm swelling of the hands and feet, along with fever. Doctors still do not know the cause of Kawasaki Syndrome – it may turn out to be a virus. Most children recover completely from it. About five percent can have some damage to blood vessels in the heart, so careful follow up is needed.
  • Erythema multiforme (air-a-theme-a mull-tee-form-ee), or EM, is a rash that spreads rapidly over the body. It usually starts as large red bumps that may become ring-shaped or resemble “targets” on the skin. Sometimes it itches. Children with EM usually don’t feel very well. In more severe cases, EM can cause sores in the mouth, red eyes, and peeling skin. It can even cause internal organ damage. Doctors don’t know exactly what causes EM – it may be a reaction to a medication or to a viral infection.