Dermatose bulleuse hémorragique associée à une réaction d'hypersensibilité retardée sous héparine de bas poids moléculaire

The case described herein shares the stereotypical clinical picture previously reported, namely small, multiple, haemorrhagic bullae on normal skin, appearing at remote sites five to 21 days after the start of subcutaneous heparin treatment. Despite the absence of clear management guidelines, it is obviously tempting to stop the heparin if there are too many bullae for fear of more clinically significant and dangerous mucous membrane lesions. The underlying physiopathological mechanism is poorly understood; no coagulation abnormalities were recorded. In addition, our patient presented an eczematous reaction at the injection sites, raising the possibility of a type IV hypersensitivity reaction. The association of these two cutaneous side effects of heparin is perhaps not purely coincidental.