Sun allergies are very common, especially among young women and people with fair skin. The most common form of sun allergy is Polymorphus Light Eruption (often abbreviated to PLE). Typical symptoms include a bumpy and irritating rash and skin redness, but you may also get blisters and pustules. Symptoms tend to develop a day or two after being in the sun and are normally on the underside of the arms and the chest − facial skin can be affected, but this is less common.
Other sun allergies include Acne Aestevalis (more commonly known as Mallorca acne). The symptoms of Acne Aestevalis closely resemble those of PLE. It typically effects women between 25 and 40 who experienced acne during puberty.
You can read about these allergies as well as how to care for allergy-prone skin in sun allergies: PLE and others.