BACKGROUND: Chronic idiopathic urticaria is a disabling condition that does not always respond to antihistamine drugs and other agents are sometimes needed to control disease activity. Warfarin has demonstrated efficacy in single unblinded case studies [1] but has been dismissed by others [2]. OBJECTIVE: We investigated the effect of warfarin treatment in eight patients with chronic idiopathic urticaria unresponsive to antihistamines in an open study. Six of the eight patients responded to treatment and three had a dramatic response. These three were included in a double-blind placebo-controlled trial of warfarin therapy to confirm significant benefit from treatment. METHODS: The three warfarin responders had their stable warfarin dose encapsulated and placebo capsules were provided. A double-blind placebo-controlled crossover trial was performed on each patient. Visual analogue scores recorded disease activity. RESULTS: Comparison of visual analogue scores showed a significant benefit while on warfarin with a reduction in pruritus and angio-oedema. CONCLUSION: This is the first double-blind placebo-controlled study to show a response of chronic idiopathic urticaria to warfarin. The mechanisms of action are unclear and require further study.
RCT Entities:
BACKGROUND:Chronic idiopathic urticaria is a disabling condition that does not always respond to antihistamine drugs and other agents are sometimes needed to control disease activity. Warfarin has demonstrated efficacy in single unblinded case studies [1] but has been dismissed by others [2]. OBJECTIVE: We investigated the effect of warfarin treatment in eight patients with chronic idiopathic urticaria unresponsive to antihistamines in an open study. Six of the eight patients responded to treatment and three had a dramatic response. These three were included in a double-blind placebo-controlled trial of warfarin therapy to confirm significant benefit from treatment. METHODS: The three warfarin responders had their stable warfarin dose encapsulated and placebo capsules were provided. A double-blind placebo-controlled crossover trial was performed on each patient. Visual analogue scores recorded disease activity. RESULTS: Comparison of visual analogue scores showed a significant benefit while on warfarin with a reduction in pruritus and angio-oedema. CONCLUSION: This is the first double-blind placebo-controlled study to show a response of chronic idiopathic urticaria to warfarin. The mechanisms of action are unclear and require further study.
Authors: Emily Lovallo; Sarah Patterson; Mitchel Erickson; Cynthia Chin; Paul Blanc; Timur S Durrani Journal: J Investig Med High Impact Case Rep Date: 2013-06-10
Authors: Paulo Ricardo Criado; Roberta Facchini Jardim Criado; Celina Wakisaka Maruta; Vitor Manoel Silva dos Reis Journal: An Bras Dermatol Date: 2015 Jan-Feb Impact factor: 1.896
Authors: Mario Sánchez-Borges; Riccardo Asero; Ignacio J Ansotegui; Ilaria Baiardini; Jonathan A Bernstein; G Walter Canonica; Richard Gower; David A Kahn; Allen P Kaplan; Connie Katelaris; Marcus Maurer; Hae Sim Park; Paul Potter; Sarbjit Saini; Paolo Tassinari; Alberto Tedeschi; Young Min Ye; Torsten Zuberbier Journal: World Allergy Organ J Date: 2012-11 Impact factor: 4.084