Allergic Contact Dermatitis

Definition

Contact dermatitis is inflammation of the skin. It happens due to contact of an external substance with the skin.

The inflammation is caused by an allergy or irritation as a result of substances found in the workplace that come into direct contact with the skin. This document explains allergic contact dermatitis.

Causes

Usually these substances cause no trouble for most people, and may not even be noticed the first time the person is exposed. Substances that cause contact dermatitis in many people include "poisonous" plants such as poison ivy, certain foods, some metals, cleaning solutions, detergents, cosmetics, perfumes, industrial chemicals, and latex rubber.

Nearly 3,000 chemical agents are capable of causing allergic contact dermatitis. Nickel, chrome, and mercury are the most common metals that cause contact dermatitis:

Neomycin, which is found in antibiotic creams, is the most common cause of medication contact dermatitis. Penicillin, sulfa medications, and local anesthetics, such as novocaine or paraben, are other possible causes.

Symptoms

The dermatitis usually shows redness, swelling and water blisters, from tiny to large. The blisters may break, forming crusts and scales. Untreated, the skin may darken and become leathery and cracked. Allergic contact dermatitis can be difficult to distinguish from other rashes, especially after it been present for a while. The reaction is generally confined to the site of contact with the allergen, although occasionally it may extend outside the contact area or it may spread all over your body.

Touching the rash or blister fluid cannot spread contact dermatitis to other people or to other parts of the body that did not make contact with the substance.

Treatment

To treat contact dermatitis, we should avoid contact with the substance that irritates your skin. Over-the-counter medications such as calamine lotion, antihistamines and ointments usually will relieve your discomfort.

Avoidance often resolves the dermatitis but if this is difficult or if the dermatitis is long standing, you will need drug treatments. Corticosteroids in the form of creams and ointments can be applied to the affected area to reduce the inflammation. Antihistamine treatments can sometimes help with redness and itching, particularly with urticaria. If possible protective clothing such as aprons and gloves should be properly selected. Not all protective clothing resists all substances. Manufacturers' specifications should be followed.