What should you know about skin allergy when exposed to sun?

A sun allergy, often called polymorphic light eruption, is an abnormal skin reaction to ultraviolet light. It may appear hours or days after sun exposure on the chest, arms, or other uncovered areas. The rash can be red, raised, spotty, or blistered, and it may itch or burn. Some medicines, cosmetics, or plant substances can make skin more light-sensitive, so the trigger is not always sunlight alone.

Limit direct sun while the rash is active, use shade and protective clothing, and choose a broad-spectrum sunscreen that your skin tolerates. Avoid scratching and pause newly introduced fragranced products until the cause is clearer. A clinician may recommend a short course of topical corticosteroids for inflammation or, for selected recurring cases, supervised narrowband UVB phototherapy to help the skin adapt. Keep a note of timing, products, medicines, and the body areas affected.

Arrange a dermatology review if the rash keeps returning, spreads despite sun avoidance, blisters, leaves marks, or interferes with sleep. Seek urgent help for swelling of the lips or tongue, trouble breathing, faintness, extensive blistering, or skin pain with fever. These features can signal a more serious reaction than a local sun-triggered rash.

Ask whether the pattern fits sun sensitivity, whether any medicine or skincare product could be contributing, and which sunscreen ingredients are suitable for you. You can also ask how to manage a flare and whether testing or preventive treatment is appropriate.