Efficacy of steroids in preventing cutaneous heparin-related allergic reactions in patients requiring anticoagulation

Heparin is a widely-prescribed drug used as an anticoagulant in the prophylaxis and treatment of thromboembolic vascular events. Its most important adverse effect is immune-based-thrombocytopaenia.1 However allergic reactions, mostly cutaneous, have been described.2–4 These may occur as an urticarial rash (presumably due to a local release of histamine), type I hypersensitivity reaction, present as skin necrosis due to vasculitis (type III Arthus reaction), or a well-circumscribed lesion without necrosis (delayed type IV hypersensitivity reaction). If the diagnosis is missed, fatal outcomes have been described especially in patients who also developed a white clot syndrome related to heparin-induced thrombocytopaenia. In cases of allergic reactions, authors recommend patients shift to oral anticoagulants. Although theoretically possible, in many cases this is not possible because the patient is unable to swallow or has difficult venous access that render difficult serial INR dosing. We describe the case of a female oncologic patient who developed diffuse pruritis and cutaneous rash to heparin only after steroids discontinuation