[Delayed allergic reaction to Chlorambucil (Leukeran). Case report and literature review]

A 63-year-old man developed a mild hemorrhagic diathesis which led to the diagnosis of chronic lymphatic leukemia. Treatment with prednisone and chlorambucil was initiated. During the first 10 day-cycle (10 mg chlorambucil and 100 mg prednisone) no side effects were noted. On the 8th day of second cycle (10 mg chlorambucil and 25 mg prednisone) the patient noticed fever, tiredness, myalgia, pruritus and erythema on the skin. The third cycle (10 mg chlorambucil alone) hat to be stopped on the second day due to the development of myalgia, generalized erythroderma with exfoliation and edema of the face and arms. In the patch-test with chlorambucil, a strongly positive (histologically verified) allergic reaction was noted. A lymphocyte stimulation test (detecting in vitro lymphocytes sensitized to chlorambucil) was also positive. These findings, together with the marked clinical reaction to chlorambucil alone, led to the diagnosis of a delayed hypersensitivity reaction to chlorambucil. Such well documented allergic reactions to chlorambucil are very rarely described in the literature. Up to now only 1 case of immune hemolytic anemia, 1 case of Lyell-syndrome, 2 cases of delayed hypersensitivity reactions and a few cases of less well documented type I reactions have been described. In all these cases no crossreactivity with other alkylating agents occurred, and hence all patients could be successfully treated with cyclophosphamide.