Hemorrhagic bullous dermatosis: a rare heparin-induced cutaneous manifestation.

Heparin is one of the most widely prescribed medications. Cutaneous reactions distant to the injection site are rare and under-reported in the literature. We present an elderly man with history of CNS lymphoma who underwent treatment of a deep venous thrombosis with enoxaparin and subsequently developed well demarcated bullous lesions within days of heparin initiation. The exact pathophysiology is not well understood. Hemorrhagic bullous dermatosis is a rare cutaneous reaction that is temporally associated with the initiation of heparin products. The handful of cases thus far suggest that regression of these seemingly benign lesions may or may not be associated with dose reduction or discontinuation of heparin products and typically occur within a few weeks. Elderly age appears to be one potential risk factor for development of these rare asymptomatic lesions. Malignancy may have some contributing factor and differentiation between this rare cutaneous manifestation from heparin products and other dermatological findings in patients with malignancy is key. Because of the asymptomatic and self-limiting nature of hemorrhagic bullous dermatoses in the setting of heparin product use, we presume that the reported incidence does not reflect true clinical practice.