[Hemorrhagic bullous dermatosis (HBD): A rare side-effect of heparins]

Background: Bullous haemorrhagic dermatosis (BHD) induced by heparin is a rare and benign side effect of which we report two cases.

Patients and methods: Case 1: an 81-year-old man presented haemorrhagic bullae on the limbs and trunk 7 days after starting enoxaparin. The laboratory haemostasis assessment was normal. A diagnosis was made of BHD induced by enoxaparin and the patient's treatment was switched to apixaban, resulting in a favourable outcome with resolution of the lesions within 15 days. Case 2: a 71-year-old woman hospitalised for pulmonary embolism was given tinzaparin. At two months of treatment, haemorrhagic bullae were observed on her forearms at distance from the injection sites. A diagnosis of BHD induced by tinzaparin was made. Treatment with tinzaparin was continued and the lesions resolved within 15 days.

Discussion: Heparin-induced BHD is a rare entity initially described in 2006. Ninety-five cases of heparin-induced BHD have been reported. It is characterized by multiple haemorrhagic bullae at a distance from the injection sites. Time to onset of lesions after heparin initiation ranges from 24h to 4 months. Laboratory assessment should be routinely performed to rule out any haemostasis disorders. Lesions subside within 15 days whether heparin is continued or withdrawn.

Conclusion: Heparin-induced BHD is a rare but benign side effect of heparins. In the absence of recommendations, therapeutic management should be adapted to the individual situation.