Dermatitis is an
inflammation, or irritation, of the skin resulting from such causes as bacteria, fungi, parasites, and foreign substances called allergens. It can arise directly from skin contact with external agents or as a result of disorders elsewhere in the body. The symptoms of
Dermatitis include itching, burning, redness, blistering, or edema (swelling). Scratching may result in secondary bacterial infection.
Skin-contact dermatitis includes primary irritant,
allergic, and
photochemical dermatitis. Primary irritant dermatitis is the most common type and is caused by the direct toxicity of certain
chemicals that come in contact with the skin. Allergic dermatitis involves the immune mechanism and requires prior sensitization of an individual to agents such as cosmetics, chemicals, plants, drugs, or costume jewelry. Photochemical dermatitis occurs when an individual with photosensitizing chemicals on his skin is exposed to light.
Atopic dermatitis, or eczema, is a chronic inflammation that appears to run in families with a history of asthma and hay fever. Stasis dermatitis (eczema of the legs) is found in elderly people suffering from vascular disease, which results in poor circulation.