Stevens-Johnson syndrome induced by combination of imatinib and allopurinol.

We report a case of Stevens-Johnson syndrome (SJS) caused by imatinib combined with allopurinol. An 82-year-old female patient who had a diagnosis of chronic myeloid leukemia was initially treated with imatinib 200 mg/day and allopurinol 100 mg for 42 days, and had a satisfactory hematological response. The dose of imatinib was adjusted to 400 mg/day for 14 days. After two weeks, she developed SJS and was transferred to the intensive care unit for further treatment because her general condition had deteriorated. The aggravated cutaneous adverse reaction improved approximately 7 days after withdrawal of imatinib. Oral steroids with antihistamines were prescribed for the treatment of severe cutaneous reaction. The symptoms of SJS completely improved 1 month after discontinuation of imatinib and allopurinol. We concluded that imatinib alone may cause serious cutaneous reaction, but the combination of 2 high-risk drugs may increase the likelihood of exposed patients developing SJS. Physicians should be aware of the possibility of SJS caused by imatinib and allopurinol prescribed simultaneously.