Class action of oral coumarins in the treatment of a patient with chronic spontaneous urticaria and delayed-pressure urticaria

摘要

Chronic spontaneous urticaria is a common condition, with a lifetime prevalence of 0.5-1.0%. It has a significant effect on quality of life, comparable to having triple-vessel coronary artery disease. Warfarin and nicoumalone are synthetic derivatives of the plant toxin coumarin. We report the first case of successful response to both warfarin and nicoumalone in the same patient, thereby demonstrating a class action of synthetic coumarins in the disease. Complete response with both coumarins occurred once an INR above 2.0 was achieved, and was maintained during a 12-month follow-up. The mechanism of action of coumarins on urticaria is not known, but may be related to decrease in thrombin production or to interference of activation of other inflammatory proteins produced during the coagulation process. Side-effects of anticoagulation can be catastrophic, and coumarin treatment currently remains reserved for restricted severe recalcitrant cases only.