Background:

Warfarin is an oral anticoagulant which is widely used in the prevention and treatment of thromboembolic events, to which multiple adverse effects are attributed; nevertheless, descriptions of hypersensitivity reactions to this medication are rare.

Case report:

A 59-year-old patient with a history of mesenteric thrombosis, who had previously received long-term treatment with warfarin. Upon discontinuation of the medication, the patient experienced a recurrence of thrombosis at a hepatosplenic level, with a subsequent hypersensitivity reaction upon administration of the coumarin. It was decided that treatment with warfarin should be continued as it was considered the best therapeutic option, which is why a rapid desensitization protocol was carried out.

Conclusion:

Hypersensitivity reactions to warfarin are rare; we propose the option of a desensitization protocol for patients who require this medication as long as the clinical benefit is considered greater than the reaction.