Abstract
Heparin is commonly used to prevent clotting; however, severe hypersensitivity reactions during vascular access (VA) placement are rarely but occasionally reported. A 49-year-old man experienced a heparin-induced hypersensitivity reaction during VA placement. Severe side effects may occur even while placing the VA; therefore, we reconsidered the routine use of heparin, as the side effects are unpredictable. Physicians should be aware of the risk of heparin-induced hypersensitivity and be ready to effectively manage it during VA placement.