About This Condition
People with photosensitivity have an immunological response to light, usually sunlight. They typically break out in a rash when exposed to sunlight; how much exposure it takes to cause a reaction varies from person to person. Several conditions, such as erythropoietic protoporphyria and polymorphous light eruption, share the common symptom of hypersensitivity to light—also typically sunlight.
People taking certain prescription drugs (sulfonamides, tetracycline, and thiazide diuretics) or herbs (St. John’s wort, for example) and those with systemic lupus erythematosus have increased susceptibility to adverse effects from sun exposure.
Symptoms may include a pink or red skin rash with blotchy blisters, scaly patches, or raised spots on areas directly exposed to the sun. The affected area may itch or burn, and the rash may last for several days. In some people, the reaction to sunlight gradually becomes less with subsequent exposures.
Other treatment includes the avoidance of direct sunlight and the use of sunscreen. In addition, individuals should avoid medications and substances that are known to cause photosensitivity.