Phytophotodermatitis is a common phototoxic dermal reaction caused by the interaction between certain plants, sunlight, and human skin. The causal agents in plants have been identified as furocoumarins, which are photoactive compounds. Although the plants causing phytophotodermatitis vary, in the United States phytophotodermatitis most commonly occurs following exposure to plants belonging to the Rutaceae and Umbelliferae families.