Everyone will burn if exposed to enough ultraviolet radiation from the sun or other sources. However, some people burn particularly easily or develop exaggerated skin reactions to sunlight. Doctors call this condition photosensitivity. For some people, consuming certain medications or plant products—or rubbing them on their skin—can cause photosensitivity. Similar reactions are seen in diseases such as some forms of porphyria (a group of usually hereditary metabolic disorders) or lupus. In another condition, called polymorphous light eruptions (PLEs), dramatic rashes can develop after fairly limited sun exposure.

The most important step toward treating photosensitivity is to identify whether an external substance is causing the reaction, and then eliminate it if possible. Antibiotics are among the most common photosensitizing drugs. Many other natural substances can also cause this reaction. Another commonsense step is to use sunscreen and wear protective clothing, or simply to stay out of the sun.

Some types of photosensitivity may respond to specific treatments such as oral beta-carotene, steroids, or other medications.