Owen A, Duong K, Symons J, Cross B, Ratchford A, et al.
Asia Pacific allergy •
Australia has the highest prevalence worldwide of tick-induced allergies (mammalian meat and tick allergy/anaphylaxis). Inappropriate tick removal techniques are known to trigger tick anaphylaxis. This study aimed to ascertain the evidence for the effectiveness of tick removal methods and their relationship to the outcomes of tick-induced allergies and tick-borne illnesses. The design involved is a systematic literature review. Scopus, Embase, and Medline were searched (September 20, 2023) for studies of tick removal techniques and for outcomes of tick-induced allergic reactions and tick-borne illnesses. Two reviewers reviewed abstracts and full texts. Included studies were appraised (Joanna Briggs Institute critical appraisal tools), and data were extracted, tabulated, and evaluated. Six studies investigated a relevant outcome, all of low or moderate quality. Tick-killing in situ before removal resulted in allergic reactions in only 3/61 patients and no anaphylaxis. 23/28 who presented to the Emergency Department following removal with tweezers had allergic reactions (one anaphylaxis). When those with known tick anaphylaxis killed ticks in situ before removal there was no subsequent anaphylactic reaction. A significant decrease in disease transmission and/or seropositivity ( and/or ) was shown with crushing ticks or gentle pressure before removal with fine-tipped forceps, forceps alone, and surgical tweezers. Manipulation before removal with tweezers made no difference to seropositivity. Few studies worldwide have examined outcomes of tick removal techniques. Tick-killing in situ reduces recurrent tick anaphylaxis in Australians. Early removal with forceps may be effective where tick-borne disease is of greater concern. Further studies of tick-killing in situ focusing upon disease transmission should be prioritized.
Tick-induced mammalian meat allergy has become an emergent allergy world-wide after van Nunen et al. first described the association between tick bites and the development of mammalian meat allergy in 2007. Cases of mammalian meat allergy have now been reported on all 6 continents where humans are bitten by ticks, in 17 countries - Australia, United States of America (USA), Europe (France, Spain, Germany, Belgium, Switzerland, Sweden, United Kingdom, Italy, and Norway), Asia (Korea and Japan), Central America (Panama), South America (Brazil), and Africa (South Africa and Ivory Coast). To date, in each of these countries, bites from only a single tick species have been linked to the development of mammalian meat allergy: (Australia), (USA), (Europe), and (Panama) are confirmed as culprits, and (Japan and Korea), (Brazil), (Ivory Coast), and (Japan) suspected of provoking mammalian meat allergy after tick bite. Other tick species remain to be formally identified (South Africa). Identification of tick species associated with development of mammalian meat allergy is crucial to the uptake of public health measures to prevent tick bites from culprit tick species, for both individuals living in these tick-endemic areas and those who choose to visit these regions. We report a tick associated with the enhancement of mammalian meat anaphylaxis after tick bite which is novel for both Australia and the world and establishes () as a second tick species associated with mammalian meat allergy in Australia.
Mammalian meat allergy after tick bites and tick anaphylaxis are the most serious tick-induced allergies. They are often severe, should be largely avoidable and offer fascinating insights into the development and prevention of allergies. Australian clinicians reported the first cases of tick anaphylaxis and discovered the association between tick bites and the development of mammalian meat allergy. The subsequent finding of the allergen epitope within the meat responsible for the allergic reaction, α-gal (galactose-α-1,3-galactose), stimulated further interest in this emergent allergy. Reports of mammalian meat allergy associated with bites from several tick species have now come from every continent where humans are bitten by ticks. The number of diagnosed patients has continued to rise. Clinically, mammalian meat allergy and tick anaphylaxis present quite differently. The prominent role of cofactors in triggering episodes of mammalian meat allergy can make its diagnosis difficult. Management of mammalian meat allergy is complicated by the manifold potential therapeutic implications due to the widespread distribution of the mammalian meat allergen, α-gal. Exposures to α-gal-containing medications have proved lethal in a minority of people, and fatal tick anaphylaxis has been reported in Australia. Prevention of tick bites is prudent and practicable; killing the tick in situ is crucial to both primary and secondary prevention of allergic reactions. Mechanisms in the development of mammalian meat allergy constitute a paradigm for how allergies might arise.