What should you know about sun rays allergy?

Polymorphic light eruption is a delayed skin reaction to ultraviolet light. Small bumps, patches or blisters may develop on areas exposed to the sun, such as the arms, chest or neck. Itching or burning can be more noticeable than pain. The rash may occur after the first strong sun exposure following a period with little sunlight, and it can return with later exposure. It is different from ordinary sunburn, which more often causes tender, uniformly red skin after too much ultraviolet exposure. A medicine or an underlying condition can also make skin more sensitive to light, so a clinician may review your medicines and examine the rash before confirming the cause.

Limit direct sun while the rash settles. Wear tightly woven clothing, a broad-brimmed hat and sunscreen labelled broad spectrum, and reapply it as directed. Seek shade and remember that ultraviolet light can reach you through windows or reflected from pale surfaces. Cool compresses may calm itching; avoid scratching, fragranced products and deliberate tanning. A pharmacist or dermatologist may suggest an appropriate anti-itch treatment or a short course of a topical corticosteroid. If flares recur, supervised light treatment such as narrowband UVB phototherapy may help the skin gradually adapt, but it should be planned and monitored by a qualified clinician.

Arrange a dermatology assessment if the rash is recurring, spreading, severe, leaving marks, or not settling after you avoid sunlight. Seek urgent help for swelling of the lips, tongue or throat, breathing difficulty, faintness, or widespread raised itchy welts, because these can signal a serious allergic reaction. Prompt medical review is also appropriate when blisters are extensive, the skin is very painful, you have fever, or the eyes are involved. Take a list of medicines and photos showing when the rash appeared; the timing and distribution can help distinguish sun allergy from other light-sensitive conditions.

Ask: Could this be polymorphic light eruption or another cause of light sensitivity? Which medicines, skincare products or illnesses should be reviewed? What level of sun protection is suitable for my daily routine? Should I use a prescribed cream during a flare, and how should it be applied? Would supervised phototherapy be appropriate if the rash keeps returning?