dermatitis

Dermatitis is a general term for inflammatory conditions of the skin, typically characterized by itching, redness, swelling, and sometimes vesicles, crusting, or scaling. It encompasses several subtypes, with atopic dermatitis, contact dermatitis, seborrheic dermatitis, and stasis dermatitis among the most common. The underlying problem often involves skin barrier dysfunction and dysregulated inflammatory responses.

Atopic dermatitis is a chronic, relapsing condition usually beginning in childhood and often associated with a personal or family history of atopy such as asthma or hay fever. It causes intensely itchy, dry skin that may run in flares. Contact dermatitis results from exposure to irritants or allergens and presents as a localized rash at the exposure site. Allergic contact dermatitis is a type IV hypersensitivity reaction, with triggers including nickel, fragrances, latex, and certain plants.

Seborrheic dermatitis presents with greasy scales and redness, commonly on the scalp, face, and chest. Its exact cause is not fully understood but may involve Malassezia yeast and inflammatory processes. Stasis dermatitis occurs in people with chronic venous insufficiency, typically on the legs, and is associated with swelling and brownish discolouration.

Diagnosis is usually clinical, based on history and examination. Patch testing or skin biopsy may be used to identify specific allergens or exclude other conditions. Management focuses on identifying and avoiding triggers, maintaining skin hydration with emollients, and reducing inflammation with topical corticosteroids or calcineurin inhibitors. Severe or stubborn cases may require phototherapy or systemic treatments such as dupilumab in atopic dermatitis.

Prognosis varies by subtype and severity but many forms are manageable with ongoing care. Dermatitis is common worldwide and can be associated with lifestyle and environmental factors.