Contact dermatitis is a skin reaction that occurs after you have been exposed to a substance that either irritates your skin or triggers an allergic response. If your skin condition is caused by contact with an irritating or harsh substance, you have primary irritant contact dermatitis. If your skin condition is an allergic reaction to a substance, you have allergic contact dermatitis. The symptoms and treatment of both types of contact dermatitis are similar.
Fluid-filled bumps or blisters, tenderness and redness of the skin often occur with contact dermatitis. You may also notice oozing cracks or fissures in the reddened, irritated skin areas. Usually, these symptoms will occur only in the areas that actually came into contact with the irritant or allergen. The affected areas will probably itch and burn.
This condition is not contagious. If you and a friend handle a primary irritant, you will both get a reaction. And if a friend wears something that you are sensitive to and the two of you are in close contact, you may also develop a skin reaction. However, in neither case did you "get" the condition from your friend.
WHAT CAUSES IT?
Step one - to determine the cause of your skin reaction, do some detective work. If your rash has begun recently, it is helpful to identify what you are doing differently. Have you changed laundry detergents or bath soaps? Are you using a new kind of perfume or aftershave? Are you wearing new shoes? The most common culprits are laundry detergents, fabric softeners, perfumed soaps, perfumes, colognes, makeup, latex gloves, smoke, irritant plants (i.e., poison ivy, poison sumac, poison oak), dyes and nickel. Nickel may be used in bra stays, hairpins, eyelash curlers, eyeglass frames, necklace clasps, zippers, garter clasps, thimbles, watchbands, insecticides, fungicides, jewelry and more.
Step two - note exactly which parts of your body are involved. Foot involvement may indicate an allergy to foot powder, leather tanning agents, shoe glue, foot inserts or buckles. Earlobes are usually irritated by earrings that contain nickel. A reaction around your eyes signals a response to airborne irritants (i.e., plants, pollen, sprays), fingernail polish or cosmetics. Mouth irritations are often caused by toothpaste, lip balm or mouthwash. Your neck may be sensitive to cosmetics, perfume or aftershave (especially if you have also been exposed to sunlight). Your underarm area may be irritated by antiperspirants, deodorants, clothing or fabrics (especially wool). Detergents are often implicated if your hands are affected. If you handle oil or tars, fiberglass, rubber compounds, latex gloves, clothing dyes, chemical finishes, adhesive tape, soaps, detergents, bleaches, cleansers, acids (including vinegar and antiseptics) or metal salts, any part of your body that contacts such substances can develop a skin reaction.
Step three - if you are unable to determine which substance is causing the problem, there are two schemes that may be used to identify the source of your skin reaction. (1) You can eliminate contact with all suspected items until your rash clears. Then, you can gradually reintroduce one article at a time to test for reaction. This method reduces your risk of further irritation and allows you to determine exactly which article is at fault. (2) A second method is to have your medical practitioner do a "patch test." This test exposes small amounts of your skin to the substances suspected of causing the reaction.
This test can give fast results, but may not isolate exactly which article is causing your difficulty (i.e., a positive patch test reaction to wool may implicate a sweater that actually does not contact the skin, when the actual culprit is your underarm deodorant). Since they are not done at McKinley, patients are referred to a dermatologist or allergist for "patch tests."
WHAT CAN I DO?
The severity of your response to a substance can be worsened by several factors including: poor health, damaged skin, repeated friction of the object against your skin (i.e., performing an aerobic routine on wool carpet), perfuse perspiration, frequent exposure to the irritating agent, and the strength or potency of the substance. If you are unable to totally avoid the substance causing your reaction, changing any one of these factors may improve your condition.
However, the best treatment for contact dermatitis is to avoid the substance causing the reaction until your lesions heal and the culprit can be identified. Here are seven comfort measures that can help you feel better:
If the irritated areas itch, apply cool, damp compresses. Do not scratch them.
Avoid hot water. Decrease the number of showers and baths you take.
Avoid soaps, detergents and overheated rooms.
If dryness of your irritated areas is a problem, use a low alcohol content "unscented" emollient (i.e., Aquaphor, Eucerin, Vaseline or Acid Mantle).
DO NOT put alcohol or antiseptic lotions on your lesions.
If your medical practitioner recommends a corticosteroid cream, use only the amount prescribed (more is not better).
If your medical practitioner prescribes oral steroids (i.e., Prednisone), take your daily dose exactly as prescribed.
Cecil's Textbook of Medicine, 21st Ed., 2000, page 2277