Contact Dermatitis

Contact dermatitis is a localized rash or irritation of the skin caused by contact with a foreign substance. Or a condition in which the skin becomes red, sore, or inflamed after direct contact with a substance.

Two kinds of contact dermatitis: 

Irritant dermatitis is the most common type. It's caused by contact with acids, alkaline materials such as soaps and detergents, fabric softeners, solvents, or other chemicals. The reaction usually looks like a burn.

Other irritants may include:

• Cement
• Hair dyes
• Long-term exposure to wet diapers
• Pesticides or weed killers
• Rubber gloves
• Shampoos

Allergic contact dermatitis is caused by exposure to a substance or material to which you have become extra sensitive or allergic.

Common allergens include:

• Adhesives, including those used for false eyelashes or toupees
• Antibiotics such as neomycin rubbed on the surface of the skin
• Balsam of Peru (used in many personal products and cosmetics, as well as in many foods and drinks)
• Fabrics and clothing
• Fragrances in perfumes, cosmetics, soaps, and moisturizers
• Nail polish, hair dyes, and permanent wave solutions
• Nickel or other metals (found in jewelry, watch straps, metal zips, bra hooks, buttons, pocketknives, lipstick holders, and powder compacts)
• Poison ivy, poison oak, poison sumac, and other plants
• Rubber or latex gloves or shoes

Although you may not have a reaction to a substance when you are first exposed to it, regular use can eventually cause sensitivity and a reaction to the product.

Some products cause a reaction only when the skin is also exposed to sunlight (photosensitivity). These include shaving lotions, sunscreens, sulfa ointments, some perfumes, coal tar products, and oil from the skin of a lime. A few airborne allergens, such as ragweed or insecticide spray, can cause contact dermatitis.

When Skin Damage Causes a Rash

Some rashes look like an allergic reaction but really aren’t because your immune system isn’t involved. Instead, you touched something that directly hurt your skin. The longer that thing stayed on your skin, the worse the reaction. It’s called irritant contact dermatitis.

If you have eczema, you’re more likely to get this kind of a rash.

Treating a Rash at Home

• Don’t touch the thing that caused the rash.
• If you can wash your skin with mild soap and cool water right after exposure, you may get rid of all or most of the problem substance. That will help reduce symptoms.
• For blisters, try applying cold moist compresses for 30 minutes three times a day.
• Oral antihistamines can help relieve itching.
• Don’t use an antihistamine lotion unless suggested by your doctor, because it sometimes can cause skin irritation or an allergic reaction.
• If the rash covers only a small area, a hydrocortisone cream may be all you need for relief.