Dermatitis is a skin condition caused by contact with something that irritates the skin or causes an allergic reaction. It usually occurs where the irritant touches the skin, but not always. The physical symptoms of dermatitis include: redness, scaling, flaking, blistering, weeping, cracking or swelling. The symptoms may be accompanied by itching and pain. The symptoms can be so bad that the sufferer is unable to work. Detected and treated in its early stages dermatitis can be arrested and good recovery made. However, failure to seek early advice and treatment can lead to severe long term skin problems and sensitivity to a wide range of substances. There are three main types of dermatitis; irritant contact dermatitis, allergic contact dermatitis and contact urticaria. Irritant contact dermatitis can occur soon after contact with a strong irritant, or over a longer period from repeated contact with weaker irritants. These irritants can be chemical, biological, mechanical or physical. Allergic contact dermatitis occurs when the sufferer develops an allergy to a substance. ‘Sensitisation’ is likely to be permanent and further skin contact with that substance will lead to another episode of dermatitis. Urticaria is an acute reaction which occurs within minutes of a sensitizing material, organic or inorganic, touching the skin. The rash usually disappears within a few hours and in most cases it has completely gone within twenty-four hours. Materials which commonly cause dermatitis include: solvents, oils, soaps, detergents, bleach, hairdressing and beauty products, rubber, latex, and plants. See also; Occupational Health Assessment.