When are topical corticosteroids recommended for sun allergy?

Polymorphic light eruption can appear after light exposure as itchy bumps, red patches or small blisters on areas that were uncovered. The appearance can vary between people and between episodes. A topical corticosteroid reduces inflammation during a flare; it does not prevent every future episode. A rash after sunlight can also have other explanations, including a product or medicine reaction, so the history of exposure is useful.

Cover the affected skin, seek shade and follow the sun-protection plan recommended for you. Use the prescribed corticosteroid in the amount and pattern advised, taking extra care with the face, folds and other thin skin. Avoid scratching, hot showers and fragranced products while the skin is reactive. Keep notes about timing, body areas, products and medicines around each episode. Read more in [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/).

Arrange a review if the rash appears on covered skin, becomes widespread, forms large blisters, recurs despite careful protection or does not settle as expected. Seek urgent help for breathing difficulty, facial swelling, fever, severe pain or extensive blistering.

Ask whether the pattern fits polymorphic light eruption, how to protect your skin during future exposure, whether medicines or products are contributing, and when a flare needs reassessment.