Imatinib 為第一個小分子蛋白質酪氨酸激酶抑制劑 (tyrosine kinase inhibitor)，被美國食品藥品管理局核准作為慢性骨髓性白血病及惡性胃腸道基質瘤的第一線治療。除血液方面外，imatinib 最常見的副作用之一為皮膚不良反應，其導致「伴隨嗜伊紅性白血球增加與全身症狀的藥物反應」 (Drug Reaction with Eosinophilia and Systemic Symptoms, DRESS) 之嚴重皮膚不良反應目前僅有零星案例被報導。
本文探討一位66 歲女性病人使用imatinib 治療惡性胃腸道基質瘤，4 週後出現發燒、皮膚疹及嗜伊紅性白血球增加的情形。入院後肝功能持續惡化合併肝衰竭，經停藥及給予支持性治療後逐漸好轉。依據Naranjo scale 評估imatinib 與不良反應之間關聯性為7 分，屬於「極有可能」。希望藉由此個案報告及文獻回顧，能讓更多臨床醫療人員及照護者熟悉此一疾病的進程、診斷及治療；一旦發生此不良反應時，能及早停藥並適時給予醫療措施，降低DRESS 的嚴重性及致死率。

Imatinib mesylate is the first small-molecule tyrosine kinase inhibitor that has been approved by the U.S. Food and Drug Administration (FDA) as the first-line therapy for chronic myeloid leukemia (CML) and gastrointestinal stromal tumor (GIST). Adverse cutaneous drug reactions are the most common nonhematological side effects of imatinib. However, the imatinib-induced drug reaction with eosinophilia and systemic symptoms (DRESS) has been rarely reported.
We presented a case of DRESS by imatinib. Following the imatinib therapy for four weeks, a 66-year-old GIST female developed typical symptoms of DRESS, i.e., fever, rash, and high eosinophil count. Her liver function became deteriorated possibly because of the imatinib therapy. Immediate discontinuation of imatinib and appropriate supportive care improved the patient condition in a few weeks. According to the Naranjo adverse drug reaction probability scale, the development of adverse drug reaction in this case was probably associated with the imatinib treatment (score = 7).
The literature review and the present imatinib-related DRESS case may provide clinical staffs with necessary insights of prevention and intervention of the disease. Importantly, immediate discontinuation of imatinib and appropriate supportive care are critical to minimize associated morbidity and mortality of the DRESS.