How common is sun sensitivity in sun allergy?

Polymorphic light eruption usually causes an itchy rash after skin receives more sunlight than it has recently experienced. Small bumps, patches, or blister-like spots can occur on the chest, arms, neck, or lower legs. The face may be less affected in some people. The rash can vary in appearance, which is why the term polymorphic is used.

Episodes often follow a change in light exposure, such as the first brighter days of a season or a sunny trip. The timing, distribution, and repeated pattern are more useful than the presence of any single spot. Other light-sensitive conditions can look similar and need separate assessment.

Increase sun exposure gradually, use shade and protective clothing, and apply a broad-spectrum sunscreen to exposed skin. Avoid deliberate tanning while the rash is active. A clinician may recommend a treatment for itching or inflammation after examining the rash and checking your medicines and skin products. Photographing an episode can help if it fades before your visit.

Obtain urgent help for breathing difficulty, swelling of the face or throat, faintness, widespread blistering, severe skin pain, peeling, fever, or sores involving the eyes or mouth. Book a clinical assessment for a first episode, repeated flares, a rash that does not settle, or symptoms appearing on covered skin.

Ask whether your rash fits polymorphic light eruption, how to protect your skin during outdoor activities, whether any medicine increases light sensitivity, and what to use for itch. Ask when it is safe to resume normal outdoor exposure.