What is contact dermatitis?

Contact dermatitis is an inflammation of the skin that happens when a substance touches the skin. It can occur in one area and spread to other areas.

How does it occur?

Contact dermatitis occurs when the skin touches a substance that irritates the skin or causes an allergic reaction. Common causes of contact dermatitis from irritants are soaps, detergents, solvents, waxes, polishes, and hand cleaners. Common causes of contact dermatitis from allergic reactions are hair dyes, jewelry, fingernail polish, and deodorants. Some of the other substances that might cause contact dermatitis are rubber, nickel, and poison ivy.

What are the symptoms?

The symptoms of contact dermatitis include:

• swelling

• redness of the skin

• blisters that may break open and ooze, crust, or scale, possibly causing a secondary infection.

How is it diagnosed?

The doctor will ask you what substances you have been exposed to recently. The doctor may use a patch test to determine if you are allergic to a certain substance.

In a patch test chemicals are applied to the skin to see if a reaction occurs. Some substances used in the test include the chemicals found in hair dyes, perfume fragrances in cosmetics, and jewelry.

How is it treated?

If the substance that caused your reaction is identified, you and the doctor will discuss ways you can avoid contact with the substance.

If the doctor cannot identify the substance that caused the contact dermatitis, he or she will suggest that you limit contact with soap, detergent, bleach, and solvents, and that you wash thoroughly after any contact with these substances. The doctor may also suggest wearing rubber gloves and using hypoallergenic cosmetics.

If you react to a number of substances, you can take oatmeal baths. (Special oatmeal is available in drug stores.)

The doctor may prescribe a special cream or ointment for dermatitis. If your skin itches, the doctor may prescribe an antihistamine.

How long will the effects last?

Untreated and uncomplicated cases may last up to 14 days, or as long as there is contact with the substance that irritates your skin.

How can I take care of myself?

Follow the instructions the doctor gives you. In addition, you can:

• Avoid further irritating the area of skin where you have contact dermatitis.

• Avoid further contact with the substance that appears to cause the dermatitis.

• Put moist towels on the areas of skin with dermatitis.

If the affected area is too large to cover with compresses, take three or four baths in lukewarm water every day. Don't wash with soap. Sometimes it is soothing to mix cornstarch and water into a paste and add it to the tub water.

How can I help prevent contact dermatitis?

If you know what substance caused the dermatitis, make sure that the substance is not one of the ingredients in the cosmetic, cleaning, or other products that you use.

If you are allergic to nickel, find out what metal is in jewelry before you wear it.

Whether or not you know what substances give you contact dermatitis, it may be helpful to:

• Learn to recognize poison oak, poison ivy, and ragweed, and avoid contact with them.

• Use hypoallergenic cosmetics.

• Wash any exposed area immediately and thoroughly.

• Pat your skin dry instead of rubbing it.

• Try to avoid using solvents and chemicals, and wear heavy gloves when you must use them.

• Use a dishwasher, or wear rubber gloves to wash dishes.