Eczema

For a lay person:

Eczema is a common condition that makes the skin dry, itchy and inflamed. The most common type, atopic eczema, often starts in childhood and is linked to asthma and hay fever. It tends to flare and settle, and can be triggered by soaps, heat, stress or allergens.

For a trained medical person:

Atopic dermatitis results from skin barrier dysfunction (including filaggrin mutations) and type 2 immune inflammation, with other forms including contact, seborrhoeic and discoid eczema. Diagnosis is clinical, with patch testing for suspected allergic contact dermatitis. Management is emollients and trigger avoidance, topical corticosteroids or calcineurin inhibitors for flares, and phototherapy, systemic immunosuppressants or biologics for severe disease.

In Chinese medicine:

Liu and Tseng's textbook differentiates this condition into these patterns: Damp-Heat Excess; Concomitant Wind and Damp; Wind-Damp-Heat; Damaged Yin and Residual Damp. Treatment follows the pattern a patient presents with, not the Western diagnosis alone.

When to get help: See a doctor for eczema that is weeping, crusted or very painful, or with fever, as this can mean infection; eczema herpeticum (clustered blisters and feeling unwell) needs same-day care. Some oral Chinese herbal remedies for eczema have caused liver injury or been found to contain undeclared steroids.