Delayed Anaphylaxis to Red Meat Masquerading as Idiopathic Anaphylaxis

Abstract

Anaphylaxis is traditionally recognized as a rapidly developing combination of symptoms often including hives and hypotension or respiratory symptoms. Furthermore, when a specific cause is identified, exposure to this cause is usually noted to have occurred within minutes to 2 hours before the onset of symptoms. This case is of a 79 year-old female who developed a severe episode of anaphylaxis 3 hours after eating pork. Prior to 2012, she had not experienced any symptoms after ingestion of meat products. Delayed anaphylaxis to mammalian meat has many contrasting features to immediate food-induced anaphylaxis. The relevant IgE antibody is specific for the oligosaccharide galactose-alpha-1,3-galactose (alpha-gal), a blood group substance of non-primate mammals. Evidence from Australia, Sweden, and the U.S. demonstrates that the primary cause of this IgE antibody response is tick bites. These bites characteristically itch for ten days or more. Diagnosis can be made by the presence of specific IgE to beef, pork, lamb, and milk and lack of IgE to chicken, turkey, and fish. Prick skin tests (but not intradermal tests) are generally negative. Management of these cases, now common across the southeastern U.S., consists of education combined with avoidance of both red meat and further tick bites.

Delayed red meat allergy: clinical ramifications of galactose-α-1,3-galactose sensitization

“…14 Although low-density and very low-density lipoproteins can cause basophils to upregulate, evidenced by increased CD63 activation, development of symptoms is believed to be due to mast cell degranulation rather than basophil activation. 12,14 Basophil activation correlates with onset of clinical symptoms and can serve as a marker for the presence of alpha-gal in the bloodstream. 12 …”

“…Onset is typically in adults, although children are not excluded. 4,14 Kennedy et al 18 identified 45 pediatric patients with the allergy. In the United States, red meat typically includes beef, pork, and lamb.…”

“…13 After investigation into cetuximab reactions, initially identified in Tennessee and North Carolina, 8 a group of patients with delayed red meat allergy was discovered in the same geographic distribution. 9,10,14 Isotype switching to alpha-gal IgE can occur in the skin, resulting in sensitization to the alpha-gal epitope, although the exact mechanism remains unknown. 9,14 The suspected trigger for isotype switch to IgE is believed to occur after an ectoparasite bite.…”

“…9,10,14 Isotype switching to alpha-gal IgE can occur in the skin, resulting in sensitization to the alpha-gal epitope, although the exact mechanism remains unknown. 9,14 The suspected trigger for isotype switch to IgE is believed to occur after an ectoparasite bite. IgE to the alpha-gal epitope was isolated in the serum of patients with delayed red meat allergy, just as in those with cetuximab hypersensitivity.…”

“…9,10 Currently, the distribution of A americanum in the United States is primarily in the Southeast; however, investigators believe the geographic area of the tick is continuing to expand (Fig 2). 10,14,15 Other ticks have been identified as vectors in different countries, such as Ixodes ricinius in Europe and Ixodes holocyclus in Australia. 16,17 Pathophysiology…”