An Uncommon Cause of Gastrointestinal Bleeding in an 84-Year-Old Female

The estimated annual incidence for drug-induced thrombocytopenia is 10 per million. Although fatal consequences are uncommon, life-threatening hemorrhage can occur due to spontaneous bleeding. We report a case of 84-year-old Caucasian female who presented to the emergency department with multiple episodes of bloody bowel movements. One week prior to this admission, she was started on trimethoprim-sulfamethoxazole for the treatment of skin abscess. On admission laboratory results showed platelet count of 4 × 103/mm3 and hemoglobin of 10.2？g/dL. Because of unstable vital signs, the patient was transferred to the intensive care unit where she received multiple units of platelet and blood transfusion. Drug-induced thrombocytopenia due to TMP/SMX was suspected. Intravenous methylprednisolone was started as well as immune globulin with good clinical response. 1. Introduction Since trimethoprim-sulfamethoxazole (TMP/SMX) has been available in 1968, it has been used for the treatment of various infections, including bacterial and nonbacterial infections [1]. Its hematologic adverse effect, particularly thrombocytopenia, is well documented [2–4]. The overall estimated incidence for drug-induced thrombocytopenia (DITP) is 10 per million populations per year [5]. Although fatal consequences are uncommon, life-threatening hemorrhage can occur when platelets are less than 10 × 103/mm3 due to spontaneous bleeding. We present an uncommon case of spontaneous life-threatening hemorrhage due to severe thrombocytopenia induced by TMP/SMX. 2. Case Presentation An 84-year-old Caucasian female presented to the emergency department with multiple episodes of bloody bowel movements developed acutely on the day of admission. Her symptoms were associated with dizziness and lightheadedness. Patient denied any other symptoms including fever, nausea, abdominal pain, or prior history of gastrointestinal bleed. Her medical history is relevant for hypertension, hyperlipidemia, osteoarthritis, and non-Hodgkin lymphoma, in remission for the last 8 years. Surgical history was positive for mitral valve repair at the age of 67 and bilateral total hip arthroplasty at the age of 74 years. Her medications included metoprolol, rosuvastatin, digoxin, and low-dose aspirin. She also reported taking ibuprofen occasionally for osteoarthritis. She denied taking other anticoagulants. Despite her age, the patient never had a screening colonoscopy. She had history of sulfa allergy but did not remember the reaction. One week prior to this admission, she was started on TMP/SMX for an abscess on her right