The patient with phototoxicity has an exaggerated sunburn reaction, with or without vesicles, edema, and hyperpigmentation. Furocoumarins are heterocyclic aromatic compounds naturally found in the skin of citrus fruits, including limes. Psoralen, a compound resembling the naturally occurring furocoumarins, has been shown to produce photosensitivity reactions. In all cases of photosensitivity, rapid diagnosis and identification of the offending agent are fundamental in effecting control. In phototoxicity, the severity of symptoms depends on the concentration of exposures, and a variety of clinical presentations may be observed within an exposed group.
Further measures call for eliminating, or at least reducing, exposure to the offending agent.
Exposure to sunlight should be minimized, sunscreens should be used, and patient education should be emphasized. In July 1983, a neurologist in Georgia saw a patient who complained of shooting pains, muscle weakness, and numbness. Results of tests of plasma and red blood cell cholinesterase activity were within the normal range for all workers tested, including the most severely ill worker. These products contained 12 types of pesticides. Employees took no special precautions to avoid skin contact with these materials, except one animal groomer who wore gloves and a dust mask when working with certain dips.