Ibuprofen-Induced Pancytopenia and Erythema Multiforme in an Elderly Female Patient.

Erythema multiforme (EM) is a delayed, cell-mediated cutaneous disease with varying clinical manifestations. It is most commonly associated with infections but can also be associated with medications, vaccines, and autoimmune diseases. Non-steroidal anti-inflammatory Drugs (NSAIDs) are commonly used analgesics that have rare associations with EM and pancytopenia. These adverse reactions to NSAIDs can obscure definitive diagnosis due to their rarity. We present a case where an elderly female patient taking 600mg of ibuprofen up to four times a day for shoulder bursitis developed EM and pancytopenia. In this case, a 75-year-old female with a medical history of atrial fibrillation, essential hypertension, non-insulin-dependent type 2 diabetes mellitus, and ischemic stroke with residual right-sided visual impairment presented to our Emergency Department in 2023 with neck swelling, skin rash, and ulceration of the oral cavity. She reported a generalized, targetoid body rash that occurred 15 days after she started taking ibuprofen regularly for left shoulder bursitis. No other medications were started before, after, or during this time period. CBC on admission was remarkable for a white blood cell count of 1.5x10