Bullous hemorrhagic dermatosis
Those affected are typically in their 60s to 80s, which may reflect the typical age of anticoagulant use, with a male to female ratio of 1.9 to 1. The lesions typically appear 2-20 days (median 7 days) after initiation of anticoagulant treatment. There are over 90 cases reported in literature, but BHD may be underreported.
The etiology of BHD is poorly understood.
L13.9 – Bullous disorder, unspecified
402750008 – Bullous dermatosis precipitated by drug treatment
Differential Diagnosis & Pitfalls
- Heparin-induced skin necrosis – Histology shows dermal thrombi on biopsy with or without associated thrombocytopenia on CBC.
- Warfarin necrosis – Clinically characterized by painful necrotic plaques in adipose-rich areas. Histology shows fibrin and thrombi in dermal vessels.
- Atypical bullous pemphigoid – Histology classically shows eosinophilic inflammation with or without subepidermal cleft / blister; direct immunofluorescence (DIF) shows linear IgG and C3 along basement membrane zone.
- Angiokeratomas (see angiokeratoma circumscriptum) – Clinical differential; distinguished by history of chronic nature.
- Hemorrhagic spider bites
Drug Reaction Data