Sun allergy in winter: what to know

Polymorphic light eruption may develop when skin encounters sunlight after a period of limited exposure. Cooler air does not remove ultraviolet light, and reflected light from snow, water, or pale surfaces can reach the face, hands, and other exposed areas. The rash may be itchy, red, raised, or made of small spots and can be mistaken for dry winter skin, eczema, or irritation from clothing. The pattern and timing help a clinician distinguish these possibilities.

Cover exposed skin with closely woven clothing, gloves, and a hat, and apply broad-spectrum sunscreen to uncovered areas even on cool or cloudy days. Reapply according to the product directions, particularly after sweating or washing. Use a bland moisturiser if cold air has made the skin dry, and stop any product that stings or causes a new rash. If flares repeat each winter, ask about a prevention plan and see [Sun Sensitivity](/symptoms/sun-sensitivity/).

Arrange medical review for a rash that spreads quickly, blisters, becomes painful, forms crusts, or fails to settle after avoiding direct exposure. Seek urgent help for facial swelling with breathing difficulty, widespread blistering, fever, eye pain, or vision changes. A recurring seasonal rash also deserves assessment because medicines, contact reactions, and other light-sensitive conditions can resemble sun allergy.

Ask which parts of your winter routine may be exposing your skin, whether a medicine increases light sensitivity, and how to protect skin during outdoor trips. If episodes are frequent, ask whether [Narrowband UVB Phototherapy](/treatments/medical-dermatology/narrowband-uvb-phototherapy/) could be considered under supervision, and when [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/) might be appropriate.