Heparin-Induced Hemorrhagic Bullous Dermatosis: A Rare Complication of Unfractionated Heparin.

We present a case of an 82-year-old female with a significant medical history of hypertension and Alzheimer's disease who developed heparin-induced hemorrhagic bullous dermatosis during treatment for a subsegmental pulmonary embolism. The patient was admitted with lower extremity edema and cyanosis, diagnosed with a subsegmental pulmonary embolism, and started on therapeutic doses of unfractionated heparin. On the sixth day of heparin therapy, she developed abdominal bloating and a diffuse exanthematous rash, which progressed to hemorrhagic bullae on the plantar and dorsal aspects of her feet, alongside extensive purpura on her legs. Laboratory findings revealed thrombocytopenia. Multidisciplinary consultations confirmed the diagnosis of heparin-induced hemorrhagic bullous dermatosis. Management included continuing unfractionated heparin with close monitoring, supportive topical treatments, and a subsequent transition to rivaroxaban. The patient's condition improved significantly, and she was discharged in stable condition. This case highlights the importance of recognizing rare adverse reactions to heparin and raises the question of preventive measures or risk factors related to this manifestation.