In severe cases the rash may cause blistering and hives. What is it? This is another allergic reaction caused when a chemical reacts with the sun in a way that causes an allergen - and therefore ...

"In many cases these are reversible reactions, so if the patient ... which causes tiny bumps or rashes to come and go with sun exposure, and chronic actinic dermatitis, which triggers year-round ...

is a condition in which the skin experiences adverse reactions to sun exposure. It typically shows up as an itchy, red rash, but a sun allergy can also cause pain, raised patches of skin ...