The dangers of herbalism.

Case report A 30 year old man of Indian extraction presented at a dermatology clinic with a six month history of photosensitivity. After being exposed to summer sunshine in London in the middle of the day he would develop erythema and itching of the hands and ears the same evening and blistering the following day. He had had extensive vitiligo for 20 years, but the photosensitivity also affected normally pigmented skin. He denied having a history of photosensitivity and said that he was not taking any drugs. He had slight postinflammatory hyperpigmentation at the site of a recent blister and vitiligo but no milia or scarring. Because he drank a moderate amount of alcohol we measured the urinary porphyrin concentration to exclude porphyria cutanea tarda, but this yielded negative results. Tests for antinuclear antibody yielded weakly positive results. He then told us that during the previous six months he had been taking a herbal infusion as a self treatment for vitiligo. This had not had much effect on the depigmentation but seemed to be related to his photosensitivity. We advised him to stop taking the infusion and three months later he had had no problems with photosensitivity until the week before, when he had taken the infusion again and sat out in the sun, whereupon the blistering had recurred.