A 73-year-old man with a history of metastatic colorectal cancer presented with multiple, asymptomatic black, crusted nodules on his arms. Two weeks prior, he had received a diagnosis of deep vein thrombosis and was prescribed low-molecular-weight heparin sodium (LMWH) subcutaneous injections (enoxaparin sodium). Five days after starting to receive anticoagulation therapy, he noted multiple blisters on his arms that grew rapidly, occasionally bled, and dried to become crusted nodules. These were distantly located from his abdominal enoxaparin injection sites.
Peña ZG, Suszko JW, Morrison LH. Hemorrhagic Bullae in a 73-Year-Old Man. JAMA Dermatol. 2013;149(7):871-872. doi:10.1001/jamadermatol.2013.3364a