Allergy Service, Istituti Clinici di Perfezionamento, Milan, Italy.
Int J Gen Med. 2011;4:783-7. doi: 10.2147/IJGM.S24324. Epub 2011 Nov 22.
Toxocara canis is an intestinal nematode affecting dogs and cats, which causes human infection when embryonated eggs excreted in dog feces are ingested. Humans are paratenic hosts. Although the larvae do not develop into adult worms in the human body, they may migrate to various tissues and organs where they can survive for several years, giving rise to several clinical symptoms, which can present in allergy-like form.
Over 5 years, we examined 9985 patients referred for suspected allergies, based on symptoms such as dermatitis, urticaria, rhinitis, asthma, and conjunctivitis; 753 patients who had allergy tests negative or unrelated to clinical history were tested for seropositivity to T. canis by enzyme-linked immunosorbent assay (ELISA) or Western blotting (WB).
In 240 patients (31.8%), ELISA or WB or both tests were positive for T. canis immunoglobulin G (IgG) antibodies: in particular, 64 of them (26.7%) were positive to ELISA, 110 (45.8%) to WB, and 66 (27.5%) to both tests. Asthma was the most common clinical presentation. Two thirds of patients underwent subsequent anthelmintic therapy and showed a complete remission of symptoms and, in 43% of patients retested by ELISA and WB, became negative to Toxocara.
These findings strongly suggest that T. canis plays a significant role in inducing chronic symptoms presenting as suspected allergies.
犬弓首蛔虫是一种影响犬猫的肠道线虫，当狗粪便中排出的受精卵被摄入时，会引起人类感染。人类是中间宿主。尽管幼虫在人体内不会发育成成虫，但它们可能迁移到各种组织和器官中，并在那里存活数年，引起多种临床症状，这些症状可能表现为过敏样形式。
在 5 年多的时间里，我们根据皮炎、荨麻疹、鼻炎、哮喘和结膜炎等症状，对 9985 名疑似过敏的患者进行了检查；对 753 名过敏测试阴性或与临床病史无关的患者进行了犬弓首蛔虫血清学检测，采用酶联免疫吸附试验（ELISA）或免疫印迹（WB）检测 T. canis 免疫球蛋白 G（IgG）抗体。
在 240 名患者（31.8%）中，ELISA 或 WB 或两者检测均为犬弓首蛔虫 IgG 抗体阳性：其中 64 名（26.7%）对 ELISA 阳性，110 名（45.8%）对 WB 阳性，66 名（27.5%）对两者均阳性。哮喘是最常见的临床表现。三分之二的患者接受了随后的驱虫治疗，症状完全缓解，在 43%的用 ELISA 和 WB 重新检测的患者中，对犬弓首蛔虫的检测转为阴性。
这些发现强烈表明，犬弓首蛔虫在引起疑似过敏的慢性症状方面起着重要作用。
