Healthy skin is a barrier between the inside of the body and the
outside environment. A rash means some change has affected the skin. A rash is
generally a minor problem or is part of an illness that will go away on its
own. A rash may be caused by contact with a substance outside the body, such as
poison ivy (contact dermatitis), or by other more serious
illnesses, such as
scarlet fever (strep throat with rash).
Generalized rashes over the whole body that are caused
by viruses are more common in babies and young children than in adults. A rash
may be caused by a viral illness if the child also has a cold, a cough, or
diarrhea, or is in a day care setting where he or she is with other children
with viral illnesses. Most rashes caused by viruses are not serious and usually
go away over a few days to a week. Home treatment is often all that is needed
to treat these rashes.
After a child has had a rash caused by a
virus, his or her body generally builds an immunity to that virus. This
immunity protects the child from getting that specific viral illness and rash
again. Common rashes caused by viruses include:
- Chickenpox (varicella). This rash is a
common, contagious illness caused by a type of herpes virus.
- Fifth disease. This facial rash looks like the cheeks
have been slapped. It also causes a lacy, pink rash on the arms and legs,
torso, and buttocks.
- Roseola (roseola infantum). This rash
occurs about 3 days after a high fever.
- Unknown virus. Sometimes
the specific virus that causes a rash is never known.
Localized rashes which affect one area of the body
have many different causes and may go away with home treatment. Common
localized rashes that occur during childhood include:
- Diaper rash. This rash is caused by
rubbing, moisture, chemicals, or bacteria in the baby's urine or stool;
substances in disposable diapers; or soaps used to wash cloth
- Impetigo . This bacterial skin infection is caused by
strep or staph
- Heat rash (prickly heat) . This rash often results from
a well-meaning parent dressing his or her baby too warmly, but it can happen to
any baby in very hot weather.
- Cold sores.
These are sometimes called fever blisters. Cold sores are clusters of small
blisters on the lip and outer edge of the mouth caused by the herpes simplex
- Contact dermatitis . This rash is caused by contact
with a substance, such as food, soap, or lotion, that causes an
allergic reaction. Most contact dermatitis is mild and
goes away when your child's skin no longer comes in contact with the
- Cradle cap. Cradle
cap is an oily, yellow scaling or crusting on a baby's scalp. It is common in
babies and is easily treated.
Cradle cap is not a part of any illness and does not mean that a baby is not
being well cared for.