Severe phototoxic reaction to laser treatment in a patient taking St John's Wort.

Potential patients in the developed world are increasingly turning to treatment with herbs. One of the most popular herbs taken for depression is St John's Wort, which contains the potential photosensitizer hypericin. 'Hypericism' is a term used to describe a state of skin sensitivity to visible light in animals following ingestion of hypericin-containing plants and feed. A patient who developed a severe phototoxic reaction to laser light at 532 nm and also an exaggerated and unexpectedly severe response to pulsed dye laser light at 585 nm is described. It subsequently transpired that the patient was taking St John's Wort at the time of laser treatment.