Division of Allergy and Immunology, Department of Internal Medicine, University of Virginia Health System, Charlottesville, VA 22908, USA.
Pediatrics. 2013 May;131(5):e1545-52. doi: 10.1542/peds.2012-2585. Epub 2013 Apr 8.
Despite a thorough history and comprehensive testing, many children who present with recurrent symptoms consistent with allergic reactions elude diagnosis. Recent research has identified a novel cause for "idiopathic" allergic reactions; immunoglobulin E (IgE) antibody specific for the carbohydrate galactose-α-1,3-galactose (α-Gal) has been associated with delayed urticaria and anaphylaxis that occurs 3 to 6 hours after eating beef, pork, or lamb. We sought to determine whether IgE antibody to α-Gal was present in sera of pediatric patients who reported idiopathic anaphylaxis or urticaria.
Patients aged 4 to 17 were enrolled in an institutional review board-approved protocol at the University of Virginia and private practice allergy offices in Lynchburg, VA. Sera was obtained and analyzed by ImmunoCAP for total IgE and specific IgE to α-Gal, beef, pork, cat epithelium and dander, Fel d 1, dog dander, and milk.
Forty-five pediatric patients were identified who had both clinical histories supporting delayed anaphylaxis or urticaria to mammalian meat and IgE antibody specific for α-Gal. In addition, most of these cases had a history of tick bites within the past year, which itched and persisted.
A novel form of anaphylaxis and urticaria that occurs 3 to 6 hours after eating mammalian meat is not uncommon among children in our area. Identification of these cases may not be straightforward and diagnosis is best confirmed by specific testing, which should certainly be considered for children living in the area where the Lone Star tick is common.
尽管进行了详细的病史询问和全面的检查，但许多出现与过敏反应一致的反复症状的儿童仍无法确诊。最近的研究发现了“特发性”过敏反应的一个新原因；针对碳水化合物半乳糖-α-1,3-半乳糖（α-Gal）的免疫球蛋白 E（IgE）抗体与进食牛肉、猪肉或羊肉后 3 至 6 小时发生的迟发性荨麻疹和过敏反应有关。我们试图确定报告特发性过敏反应或荨麻疹的儿科患者血清中是否存在针对 α-Gal 的 IgE 抗体。
在弗吉尼亚大学和弗吉尼亚州林奇堡的私人执业过敏诊所，根据机构审查委员会批准的方案，招募了年龄在 4 至 17 岁的患者。通过 ImmunoCAP 获得血清并进行总 IgE 和针对 α-Gal、牛肉、猪肉、猫上皮和皮屑、Fel d 1、狗皮屑和牛奶的特异性 IgE 分析。
确定了 45 名儿科患者，他们均有支持对哺乳动物肉类迟发性过敏反应或荨麻疹的临床病史，并且具有针对 α-Gal 的特异性 IgE 抗体。此外，这些病例中的大多数在过去一年中都有被蜱叮咬的病史，并且伴有瘙痒和持续存在的症状。
在我们所在地区的儿童中，进食哺乳动物肉类后 3 至 6 小时发生的新型过敏反应和荨麻疹并不少见。这些病例的识别可能并不简单，最好通过特异性测试来确认诊断，对于生活在常见孤星蜱地区的儿童，应考虑进行此类测试。
