PURPOSE OF THE STUDY.
To determine whether immunoglobulin E (IgE) antibody to galactose-α-1,3-galactose (α-Gal) is present in the sera of pediatric patients who report idiopathic anaphylaxis or urticaria 3 to 6 hours after eating beef, pork, or lamb.
Children aged 4 to 17 years with a history suggestive of delayed anaphylaxis, urticaria, or angioedema (N = 51) were enrolled in an institutional review board–approved protocol at the University of Virginia and private practice offices in Lynchburg, Virginia.
Sera were obtained and analyzed by using ImmunoCAP (Phadia, Inc, Uppsala, Sweden) for total IgE and specific IgE to α-Gal, beef, pork, cat epithelium and dander, Fel d 1, dog dander, and milk.
A total of 45 children were identified who had both clinical histories supporting delayed anaphylaxis or urticaria to mammalian meat and IgE antibodies specific for α-Gal. Most of these children also had a history within the last year of tick bites that itched and persisted.
A new form of anaphylaxis and urticaria that occurs 3 to 6 hours after eating mammalian meat is not uncommon among children in the Virginia area. The diagnosis should be suspected in children with a suggestive history living in the area in which the Lone Star tick is common, and the diagnosis should be confirmed by specific serologic testing.
IgE response to α-Gal leading to delayed anaphylaxis or urticaria after eating meat is unlike any other known IgE-mediated food allergy, in which symptoms are typically immediate, often within seconds to minutes after ingestion. Most commonly, α-Gal responses occur after ingestion of beef, pork, or lamb but can occur even after milk ingestion. The authors point out that the history in a given patient is not always consistent, and they speculate that this finding is likely due to several factors, including amount of meat ingested, inconsistencies in the digestive process, and how the meat has been treated (eg, mechanical, thermal, freezing). Of interest, 90% of α-Gal patients with this syndrome report tick bites in the year before their first delayed meat reaction. Affected patients report marked pruritus at the site of bite(s) that often persists for weeks. This finding seems to suggest that tick bites may cause initial sensitization to α-Gal.
- Copyright © 2013 by the American Academy of Pediatrics