Low Molecular Weight Heparin Induced Skin Necrosis without Platelet Fall Revealing Immunoallergic Heparin Induced Thrombocytopenia

Abstract

Low molecular weight heparins (LMWH) are commonly used in the ICU setting for thromboprophylaxis as well as curative decoagulation as required during renal replacement therapy (RRT). A rare adverse event revealing immunoallergic LMWH induced thrombopenia (HIT) is skin necrosis at injection sites. We report the case of a patient presenting with skin necrosis witnessing an HIT after RRT, without thrombocytopenia. The mechanism remains unclear. Anti-PF4/heparin antibodies, functional tests (HIPA and/or SRA), and skin biopsy are of great help to evaluate differential diagnosis with a low pretest probability 4T's score.

Postoperative sugillations and necrosis

“…13 Rarely, low molecular weight heparin-induced skin necrosis in the form of an immunoallergic HIT has been described without thrombocytopenia, which did not correlate to the picture in our case. 14 Because of the severely elevated CRP level, we initiated a systemic antibiotic treatment. Moreover, we continued prophylactic anticoagulation with a low molecular weight heparin (dalteparin sodium 5000 I.E.…”

Probable fondaparinux-associated bullous hemorrhagic dermatosis

“…1 Heparin-induced thrombocytopenia is an immunoglobulin G antibody-mediated adverse drug reaction to heparin products. 13 Case reports have described a possible association between bullous hemorrhagic dermatosis and eczematous reactions at injection sites, suggesting a type IV hypersensitivity reaction. 1 This is a different immune mechanism from that involved in heparin-induced thrombocytopenia and does not confer susceptibility to other immune reactions.…”

Dermatose bulleuse hémorragique probablement associée au fondaparinux

“…La patiente a pu présenter une prédisposition à la derma tose bulleuse hémorragique, en raison de la combinaison d'un risque accru de nécrose cutanée attribuable à la thrombo cytopénie induite par l'héparine 6 mois auparavant, d'un retard de cicatrisation et d'une fragilité cutanée accrue due à son âge et à ses comorbidités 1 . La thrombocytopénie induite par l'héparine est une réaction indésirable aux produits à base d'héparine médiée par l'immunoglobuline G 13 . Des…”