Work up for the clopidogrel hypersensitivity that led to recognising the undiagnosed myelodysplastic syndrome.

Antiplatelet therapy with clopidogrel is widely used as a preventive strategy in patients with acute coronary syndrome, particularly after stent implantation. Diverse manifestations of clopidogrel hypersensitivity reaction have been reported including cutaneous, and hematologic symptoms as well as fatal reactions including thrombotic thrombocytopenic purpura (TTP). Clopidogrel cutaneous hypersensitivity reaction has been reported to occur on day 6 ± 2 of therapy. However, Shetty, et al. recently reported a case of leukocytoclastic vasculitis that appeared after one year of clopidogrel therapy. Here, we report the case of a patient with clopidogrel hypersensitivity that led to recognising the undiagnosed myelodysplastic syndrome (MDS).  A 78-year-old female visited the emergency department on October 2013 with severely itching confluent purpuric patches with vesiculation and wheal-like erythematous patches on the trunk and extremities that appeared one day prior (Figure 1). She had been taking clopidogrel since September 2011, which was started after percutaneous coronary intervention. Concomitant drugs included simvastatin, isosorbide, and sitagliptin. The patient presented with a fever (38.5°C). Laboratory tests revealed anemia (11.2 g/dL), leukocytosis (12,000/μL) with neutrophilia, and marked thrombocytopenia (25,000/μL) with normal liver and renal function. Neither eosinophilia nor lymphadenopathy was observed. TTP was ruled out by the absence of schistocytes and a normal von Willebrand Factor (vWF) multimeric pattern. Systemic and topical steroids as well as antihistamines were prescribed with simultaneous discontinuation of all drugs except sitagliptin under suspicion of drug hypersensitivity reaction. After three days, symptoms were alleviated and the patient restarted simvastatin and isosorbide, as these medications were unlikely to have caused drug hypersensitivity. Skin biopsy revealed superficial perivascular lym-