How to treat sun allergy

Polymorphic light eruption is an inflammatory response that can appear after sunlight, often as itchy bumps, patches, or small blisters on exposed skin. The timing may be delayed, so a flare can become noticeable after the outdoor activity has ended. Similar-looking eruptions can be caused by medicines, cosmetics, eczema, heat, or contact allergy. A clinician may examine the rash, review your products and medicines, and decide whether further testing is useful. Treatment works best when the trigger and the diagnosis are considered together.

During a flare, move into shade, cover the area, and avoid scratching or hot water. Use a gentle cleanser and a plain moisturiser if it does not sting. Sun protection includes clothing, shade, and sunscreen on uncovered skin; apply and reapply it as directed. A dermatologist may prescribe a topical corticosteroid to reduce inflammation for a defined course. If flares recur with seasonal exposure, supervised narrowband UVB phototherapy may be an option for selected patients. Keep a diary of exposure, symptoms, medicines, and products to help identify a pattern.

Book an appointment for a first episode, frequent recurrence, persistent dark or light marks, or symptoms that do not improve after exposure is reduced. Obtain urgent help for breathing difficulty, swelling of the lips or tongue, widespread blistering, skin peeling, fever, severe pain, or eye involvement. Avoid using leftover steroid creams, combination creams, or unlabelled lightening products without guidance.

Ask which diagnosis is most likely, whether a medicine or product could be triggering the reaction, and how long any prescribed cream should be used. Discuss a prevention plan for travel or outdoor work, the role of phototherapy, and what changes would mean you need an earlier review.