What should you know about light photosensitivity?

Photosensitivity can cause redness, warmth, itching, burning, a rash, or blistering after sunlight or another light source. The reaction may occur soon after exposure or later, and it can affect areas that receive light. Some medicines, skincare ingredients, and health conditions can make skin more reactive. A clinician may distinguish an allergy-like reaction from direct light injury and consider whether a Drug Rash is involved. The appearance of Sun Sensitivity is not enough to identify the cause.

Move out of direct light, cover exposed skin with closely woven clothing, use shade, and follow sunscreen directions on unaffected skin. Cool compresses may soothe warmth; avoid rubbing, fragranced products, tanning devices, and new active ingredients until the skin settles. Make a list of medicines, supplements, and topical products, including anything started recently. Do not stop a prescribed medicine without advice; contact the prescriber to review possible triggers and safer alternatives. A clinician can recommend suitable treatment for the reaction.

Seek medical advice if the reaction is recurring, spreading, blistering, or not settling after avoiding light. Prompt review is sensible when a new medicine is followed by a widespread rash, facial swelling, fever, or marked skin tenderness. Get urgent help for trouble breathing, swelling of the lips or tongue, faintness, severe blistering, eye pain, or signs of dehydration. Do not wait for another exposure to test whether the reaction returns.

Ask which light sources and products may be triggering the reaction, whether any medicine needs review, how to protect your skin at work or outdoors, and what symptoms require urgent help. Ask whether you need testing, how long to avoid a suspected trigger, and which cleanser, moisturiser, or treatment is suitable while the skin heals.