Allergic contact dermatitis (ACD) is a form of contact dermatitis that is the manifestation of an allergic response caused by contact with a substance; the other type being irritant contact dermatitis (ICD).

Although less common than ICD, ACD is accepted to be the most prevalent form of immunotoxicity found in humans. By its allergic nature, this form of contact dermatitis is a hypersensitive reaction.

The symptoms of allergic contact dermatitis are very similar to the ones caused by irritant contact dermatitis. The first sign of allergic contact dermatitis is the presence of a rash or skin lesion at the site of exposure. Depending on the type of allergen causing it, the rash can ooze, drain or crust and it can become raw, scaled or thickened. Also, it is possible that the skin lesion does not take the form of a rash but it may include papules, blisters, vesicles or even a simple red area. The main difference between the rash caused by allergic contact dermatitis and the one caused by irritant contact dermatitis is that the first one tends to be confined to the area where the trigger touched the skin, whereas in the second case, the rash is more likely to be widespread on the skin. Another characteristic of the allergic contact dermatitis rash is that it usually appears after a day or two of exposure to the allergen, unlike the irritant contact dermatitis which appears immediately after contact with the trigger.

Other symptoms may include itching, skin redness or inflammation, localised swelling, and the area may become more tender or warm. If left untreated, the skin may darken and become leathery and cracked, with pain also present. Vedagram provides relief for contact dermatitis through Ayurveda in the best way.