Symptoms
Symptoms of contact dermatitis may vary slightly, depending on the cause:
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ICD - In mild cases, there may be only mild redness of the skin. However, more severe cases may cause skin swelling, blistering or even ulceration. Symptoms usually begin immediately after exposure to the harmful substance, and they are limited to areas of the skin that have been touched, splashed, covered by or immersed in the irritant. For example, a janitor may develop symptoms on his hands after washing the floor with a strong detergent, while a factory worker may develop ICD on her face after an industrial solvent splashes upward.
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ACD - When contact dermatitis is caused by an allergic reaction, it usually causes skin redness, blistering and severe itching. Because ACD is a form of delayed hypersensitivity, these skin symptoms may not appear for several hours after exposure to the allergen. As in ICD, the distribution and pattern of the skin reaction may provide clues to the cause of the skin problem. For example, poison ivy usually appears as a pattern of tiny lines or streaks in places where plant leaves have brushed against the skin. Allergies to metal jewelry often cause rings of skin inflammation around the neck and wrist. An allergy to laundry detergent may cause symptoms that are limited to clothed areas of the body. An allergy to tanning chemicals in leather will affect parts of the feet that are covered by shoes.
If symptoms of ICD or ACD are not treated, and the skin continues to be exposed to the substance that is triggering the skin reaction, contact dermatitis may become a chronic (long-lasting) condition. In chronic contact dermatitis, the skin eventually becomes thick, scaly and dry, with pigment changes and areas of hair loss.
