What should you know about mild solar urticaria?

Solar urticaria is a form of hives triggered by ultraviolet or visible light. It may produce raised, itchy welts, redness, burning, or swelling on exposed skin, often soon after exposure. Areas covered by clothing may be spared, although the pattern can vary. The reaction usually differs from sunburn because it develops quickly and may improve after the light is removed. Medicines, skincare products, and other light-sensitive conditions can create similar symptoms, so a clinician may need the timing and exposure history to identify the cause.

Move into shade or indoors when symptoms begin and cover exposed skin with tightly woven clothing, a wide-brimmed hat, and suitable sunscreen. Test new skincare or medicines with a clinician if you suspect they increase light sensitivity; do not stop prescribed medicine without advice. Photograph a flare and record the light source, exposed areas, timing, and symptoms. A dermatologist may discuss Antihistamine Treatment to reduce itch and hives. Oral Corticosteroid Treatment is not a self-directed option and may be considered only when a clinician feels it is appropriate.

Arrange medical assessment if reactions recur, spread beyond exposed skin, last longer than expected, or interfere with ordinary outdoor activity. Seek urgent help for swelling of the lips, tongue, throat, or face; wheezing; faintness; vomiting; or trouble breathing, as these can signal a serious allergic reaction. Widespread swelling deserves prompt assessment even if breathing is currently normal.

Which type of light appears to trigger my hives? Could a medicine or product be contributing? What protection should I use outdoors? Is an antihistamine suitable for me? What symptoms mean I should use emergency services?