Red Meat Allergies After Lone Star Tick (Amblyomma americanum) Bites

James H. Diaz, MD, DrPH

Disclosures

South Med J. 2020;113(6):267-274. 

In This Article

Abstract and Introduction

Abstract

Red meat allergies have followed tick bites on every continent except Antarctica. The sensitizing antigen is galactose-α-1,3-galactose (α-gal), an oligosaccharide constituent of nonprimate blood and meat, acquired by ticks during animal bloodfeeding. Because red meat allergy after tick bites is a worldwide phenomenon, the objectives of this review were to describe the global epidemiology of red meat allergy after tick bites and its immunological mechanisms; to identify the human risk factors for red meat allergy after tick bites; to identify the most common tick vectors of red meat allergy worldwide; to describe the clinical manifestations, diagnostic confirmation, and management of patients with red meat allergy after tick bites; and to recommend strategies for the prevention of tick bites. To meet these objectives, Internet search engines were queried with keywords to select scientific articles for review. The keywords included ticks, tick bites, allergy, anaphylaxis, and meat allergy. The study period was defined as 1980–2019. The major risk factors for red meat allergy after tick bites included male sex, non-B blood type, systemic mastocytosis, a bioprosthetic (bovine or porcine) heart valve, and preexisting allergies to gelatin or animal dander. Following confirmation by challenge testing, patients with red meat allergies should avoid red meats, foods containing gelatin, and intravenous immunotherapy with monoclonal antibodies such as cetuximab and infliximab produced in SP2/0 mouse cell lines. Red meat allergy after tick bites represents an emerging threat from tick bites in addition to infectious diseases.

Introduction

Immunoglobulin E (IgE)–mediated allergic reactions to tick bites were first described in Australia in the 1980s following paralysis tick (Ixodes holocyclus) bites.[1] These reactions were characterized by urticaria, angioedema, and, in some cases, anaphylaxis.[2] In 2007, 25 patients who lived in a paralysis tick-endemic region near Sydney, Australia, developed red meat allergies after paralysis tick bites.[2] All of the cases presented as anaphylaxis or combinations of urticaria, angioedema, and anaphylaxis.[2] An immunological cross-reaction between arthropod-injected and foodborne antigens was suspected.[2]

The sensitizing antigen in these and later tick bite–linked red meat allergy cases worldwide was identified as galactose-α-1,3-galactose (α-gal).[3–6] α-Gal, an oligosaccharide constituent of all nonprimate, mammalian red meats, structurally resembles human blood group antigen B.[3–6] Ticks obtain α-gal sugars while feeding on host animals and inject small amounts of α-gal into the human circulation during bloodfeeding.[4–6] The antigen injection sensitizes high-risk individuals to α-gal in red meats, including beef, pork, lamb, goat, rabbit, horse, kangaroo, and other wild game meats.[3–6]

As a result of the increasing worldwide prevalence of reported cases of red meat allergy following tick bites, the objectives of this review are to describe the global epidemiology of red meat allergy after tick bites and its immunological mechanisms; to identify the human risk factors for developing red meat allergy after tick bites; to notify individuals of their regional risks of acquiring red meat allergy after local tick bites; to identify the most common tick vectors of red meat allergy worldwide; to describe the clinical manifestations, diagnostic confirmation, and management of patients with red meat allergy after tick bites; and to recommend strategies for the prevention of tick bites.

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....