Sun allergy and itchy skin: what to know

Polymorphic light eruption is an immune response to ultraviolet exposure. It can cause itching, prickling, redness, small bumps, or clustered patches, usually on exposed areas such as the chest, arms, neck, or legs. Symptoms may begin after time in the sun rather than immediately and can last after going indoors. Heat rash, insect bites, eczema, contact dermatitis, and some medicines can produce similar itch, so the distribution and timing matter.

Cover the affected area, move into shade, and use a cool damp cloth for short periods. Keep nails short and press or pat rather than scratch, since broken skin can become infected. Choose loose clothing and a fragrance-free moisturiser; avoid new creams, exfoliants, and fragranced products until the skin is calm. A clinician may recommend a suitable anti-inflammatory treatment. Read more about [Sun Sensitivity](/symptoms/sun-sensitivity/).

Seek medical advice if itch is severe, keeps you awake, spreads beyond exposed skin, or returns with each exposure. Prompt care is needed for painful blisters, pus, rapidly increasing warmth or redness, fever, facial swelling, breathing difficulty, or eye symptoms. A rash that does not improve after sun avoidance may have a different cause and should be examined.

Ask whether the pattern is consistent with polymorphic light eruption, whether a medicine or skin product could be contributing, and what you can use safely on the affected area. For repeated flares, ask whether supervised [Narrowband UVB Phototherapy](/treatments/medical-dermatology/narrowband-uvb-phototherapy/) is suitable and how to use [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/) correctly.