[Bullous drug reaction after pembrolizumab administration: two case reports].

Severe, blistering, adverse drug reactions involving the skin include Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Allopurinol, anticonvulsants, sulphonamide antibiotics and non-steroidal anti-inflammatory drugs in the oxicam class have been repeatedly described as triggers. Increasingly, immunotherapies are also coming into focus as triggers of severe skin reactions. Two patients with bullous skin symptoms after administration of the checkpoint inhibitor pembrolizumab are presented. As the clinical picture does not always allow an unequivocal classification, a histological assessment is often indispensable.