Wolfrom E, Chêne G, Lejoly-Boisseau H, Beylot C, Geniaux M, Taïeb A
Unité de Dermatologie pédiatrique, CHU de Bordeaux.
Ann Dermatol Venereol. 1996;123(4):240-6.
The cause of chronic urticaria remains unknown very often. Having noted several cases of chronic urticaria associated with antibodies to Toxocara canis, and lacking any other explanation, we set-up a case-control study.
Between November 1992 and April 1993, 51 adults or children with chronic urticaria (cases) who had been examined at least once at one of the three dermatology units of the Bordeaux University Hospital were matched to controls who had neither signs nor symptoms of chronic urticaria. The presence of antibodies to T. canis was measured by ELISA and Western blot.
The frequency of T. canis was 64.7 p. 100 in cases and 21 p. 100 in controls (p < 0.0001) with an odds ratio of 6.9 (95 p. 100 CI: 2.9-16.3). Cases with antibodies to T. canis were more frequently in contact with pets (84 vs 50 p. 100, p < 0.001). Of the 33 cases of chronic urticaria with antibodies to T. canis, 14 have been treated with thiabendazole or ivermectin and after a one-year follow-up, 5 (36 p. 100) were cured and 4 (29 p. 100) had improvement. No improvement occurred in the 12/19 cases not specifically treated.
The strong association between the presence of antibodies to Toxocara canis and chronic urticaria is unlikely to be due to chance. A causal relation is difficult to establish, however. Our findings should prompt further investigation of a role for Toxocara canis in chronic urticaria and the evaluation of therapeutic interventions. Preventive measures include deworming pets (dogs particularly), enclosing kitchen gardens, and handwashing before meals. A systematic measure of Toxocara canis in patients with chronic urticaria is recommended especially when in contact with dogs. Early and specific treatments can be applied on knowledge we already have.
慢性荨麻疹的病因常常不明。在注意到几例与犬弓首蛔虫抗体相关的慢性荨麻疹病例且缺乏其他解释后，我们开展了一项病例对照研究。
1992年11月至1993年4月期间，在波尔多大学医院三个皮肤科科室中至少接受过一次检查的51例慢性荨麻疹成人或儿童（病例组）与既无慢性荨麻疹体征也无症状的对照组进行匹配。通过酶联免疫吸附测定（ELISA）和蛋白质印迹法检测犬弓首蛔虫抗体的存在情况。
病例组中犬弓首蛔虫抗体阳性率为64.7%，对照组为21%（p<0.0001），比值比为6.9（95%可信区间：2.9 - 16.3）。犬弓首蛔虫抗体阳性的病例更频繁接触宠物（84%对50%，p<0.001）。在33例有犬弓首蛔虫抗体的慢性荨麻疹病例中，14例接受了噻苯达唑或伊维菌素治疗，经过一年随访，5例（36%）治愈，4例（29%）病情改善。19例未接受特异性治疗的病例中无改善情况。
犬弓首蛔虫抗体的存在与慢性荨麻疹之间的强关联不太可能是偶然的。然而，因果关系难以确立。我们的研究结果应促使对犬弓首蛔虫在慢性荨麻疹中的作用进行进一步调查以及对治疗干预措施进行评估。预防措施包括给宠物（尤其是狗）驱虫、围起菜园以及饭前洗手。建议对慢性荨麻疹患者常规检测犬弓首蛔虫抗体，尤其是在接触狗的情况下。可根据我们已有的知识进行早期和特异性治疗。
