dermatites

Dermatitis, sometimes rendered as dermatites in certain languages, refers to a group of inflammatory conditions of the skin. The conditions share features of redness (erythema), swelling, itch, and variable involvement of blisters, crusts, or scaling. They are usually localized to exposed areas or flexural creases, though distribution varies with type.

Common forms include irritant contact dermatitis, allergic contact dermatitis, atopic dermatitis (eczema), seborrheic dermatitis, dyshidrotic dermatitis, nummular dermatitis, and stasis dermatitis. Each type has distinct triggers and patterns of involvement, but they can overlap.

Symptoms typically include pruritus, burning or pain, and may progress to oozing, crusting, or thickened skin in chronic cases. Acute flares often show redness and swelling, while chronic disease can lead to rough, lichenified patches.

Causes vary by type. Irritant dermatitis results from direct chemical damage; allergic dermatitis arises from immune sensitization to substances such as nickel, fragrances, or preservatives. Atopic dermatitis has a hereditary component and is associated with other atopic disorders. Seborrheic dermatitis relates to sebaceous gland activity and yeast involvement, particularly in scalp and facial areas.

Diagnosis relies on history and examination; patch testing helps identify relevant allergens; skin biopsy is rarely required.

Management emphasizes trigger avoidance and skin barrier care with emollients. Anti-inflammatory treatment includes topical corticosteroids and calcineurin inhibitors. For infections or severe flares, systemic medications or antibiotics may be used; phototherapy may help some cases.

Prognosis varies by type and individual; many forms are chronic with recurrent flares. In children, dermatitis often improves with age, though atopic dermatitis can persist in a subset. Long-term control focuses on daily skin care and avoidance of triggers.