Most workplace skin disease comes from what touches the skin
Contact dermatitis accounts for somewhere between 90 and 95 percent of occupational skin disorders. Four in five cases come not from allergy but from plain irritation, as water, soap, solvents and detergents wear down the outer skin cells, while allergic reactions can wait a day or more before the rash appears.
The condition is inflammation of the skin's surface layers, the epidermis and the upper dermis, triggered by a chemical or physical agent. It can bring dryness, itching, a red rash, bumps, blisters or swelling. It is neither contagious nor dangerous to life, though it can be miserable, and the rash can linger for days or weeks. Symptoms persisting beyond six weeks, because exposure continues or the skin fails to recover, mark it as chronic.
There are two main routes. Irritant contact dermatitis, around 80 percent of cases, arises when repeated exposure directly injures skin cells and provokes an immune response. The rash appears straight away, tends to hurt more than it itches, leaves skin dry and cracked, and usually stays within the area actually touched, most often the hands. Allergic contact dermatitis requires an earlier sensitising exposure and involves delayed hypersensitivity: the rash typically emerges 24 to 72 hours later, itches more, may spread further, and produces small fluid blisters. Patch testing can support that diagnosis. In a third variant, phototoxic dermatitis, sunlight activates the offending substance.
Timing separates it from hives. Contact urticaria erupts within minutes of exposure and can vanish within hours, while contact dermatitis builds slowly and clears only once contact with the trigger stops. Irritants can even travel through the air and settle on exposed skin.
Allergy of this kind is surprisingly common. Pooled research suggests that up to a fifth of the general population reacts to patch tests for everyday environmental allergens. Rates are lower in people under 18 and higher in women than in men.
Source: Contact dermatitis
