Bullous dermatosis among patients with chronic renal failure of high dose frusemide

Twelve of 56 patients with chronic renal failure, all treated with frusemide (Lasix) in daily doses of 0.5-2 g, developed bullae in areas exposed to light. In most cases the bullae developed during summer months and disappeared later in the year whether the frusemide treatment was continued or not. In two patients the eruption reappeared when treatment was resumed. Disturbance of the porphyrin metabolism was not found, neither could a change in the frusemide metabolism be demonstrated. Tissue typing and blood groups showed no difference from the average population. It is concluded that the condition presumably is a photo reaction due to the frusemide treatment but it cannot be said whether it is allergic or toxic.