Fragrances are the greatest offenders. There are more than 5,000 basic fragrances, encompassing far more than cologne or perfume. Countless skin care products, soaps, shampoos, lipsticks, sunscreens and lotions contain fragrance. Some people are sensitive to the fragrance chemical used in these various products. Others are sensitive to chemical preservatives in cosmetics (to keep skin care products from spoiling) as well as antioxidants, sunscreen ingredients and other inactive ingredients.

Fragrance-free products can be safely used by those with a fragrance allergy, but even products labeled "unscented" may not be allergen-free as they may contain a masking fragrance added to cover up the chemical smell. "There are very few truly preservative-free products," warns dermatologist Anthony F. Fransway, M.D., of Fort Myers, Fla. "Most cosmetic items have an aqueous base or compartment in which bacterial and fungal overgrowth and spoilage may occur. Once a preservative allergy is identified through specific testing, cosmetics free of the offending agent may be identified and used safely."

The face, lips, eyes, ears, and neck are the most common locations for cosmetic allergy. Additionally, hands can be affected by moisturizers or nail products. Adverse reactions include irritant contact dermatitis, which produces burning, stinging, itching and redness. The most common skin irritants are bath soaps, detergents, antiperspirants, astringents, eye makeup, moisturizers, permanent hair solutions and shampoos.

Dermatologists recommend that people who experience allergic contact dermatitis follow these steps and consult a dermatologist for specific patch testing once the skin reaction is clear:

• For clothing care, double rinse all detergents and avoid all fabric softeners.
• Try to wear pure, untreated cotton.
• Avoid permanent press or cotton blends. Silk and polyester are acceptable.
• Wash all new clothing items five times before wearing.
• Use only fragrance-free soaps, body cleansers, shampoos and conditioners.
• Avoid all perfumes, colognes, and after-shaves.
• Do not use any fingernail care products or hair spray.