Patients with sunburn have an inflammatory response to ultraviolet (UV) radiation and may present with minimal discomfort or extreme pain with extensive blistering. A tender, warm erythema is seen in sun-exposed areas; vesiculation may occur, representing a second-degree burn. Exogenous photosensitivity results from the topical application or ingestion of an agent that increases the skin's sensitivity when exposed to UV light. Topically applied furocoumarins (lime juice, various fragrances, figs, celery, parsnips), PABA esters (sunscreen), and topical psoralens can cause photosensitivity at the site of application. Numerous medications, including sulfonamides, thiazides, furosemide fluoroquinolones, tetracyclines, cause photosensitivity eruptions which involves all sun-exposed areas. The exogenous photoeruption looks similar to a severe sunburn reaction, often with blistering.