Rash, Age 12 and Older - Topic Overview
Healthy skin provides a barrier between the inside of the body and
the outside environment. A rash means some change has affected the skin.
Rashes are generally caused by skin irritation, which can have many
causes. A rash is generally a minor problem that may go away with home
treatment. In some cases a rash does not go away or the skin may become so
irritated that medical care is needed.
In adults and older
children, rashes are often caused by contact with a substance that irritates
the skin (contact dermatitis). The rash usually starts within 48
hours after contact with the irritating substance. Contact dermatitis may cause
mild redness of the skin or a rash of small red bumps. A more severe reaction
may cause swelling, redness, and larger blisters. The location of the rash may
give you a clue about the cause.
Contact dermatitis does not always
occur the first time you are in contact with the irritating substance (allergen). After you have had a reaction to the
substance, a rash can occur in response to even very small amounts of the
substance. Contact dermatitis is not serious, but it is often very itchy.
Common causes of contact dermatitis include:
- Poisonous plants, such as
poison ivy, oak, or sumac.
detergents, shampoos, perfumes, cosmetics, or lotions.
- Jewelry or
- New tools, toys, appliances, or other
Latex. Allergy to natural rubber latex affects people
who are exposed to rubber products on a regular basis, especially health care
workers, rubber industry workers, and people who have had multiple surgeries.
Latex allergies can cause a severe reaction.
Rashes may occur with viral infections, such as
herpes zoster; fungal infections, such as a yeast
infection (Candida albicans); bacterial infections, such
sexually transmitted infections (STIs). Rashes may also
occur as a symptom of a more serious disease, such as liver disease, kidney
disease, or some types of cancer.
Rashes may also appear
after exposure to an insect or a parasite, such as the
scabies mite. You may develop a rash when you travel
to a rural area or go hiking or camping in the woods.