Ant allergy in Asia and Australia

Purpose of review Anaphylaxis due to ant sting is increasingly being recognized as a significant problem. Severe allergic reactions to ants are well described in the south-eastern United States, but have only been recognized in recent years as being important in other parts of the world. There are many different ant species and their distribution around the world varies. The purpose of this review is to familiarize the reader with the epidemiology and clinical characteristics of ant allergy in Asia and Australia. Recent findings In Korea, allergy to Pachycondyla chinensis (subfamily Ponerinae) has been well described. In an ant-endemic area, sensitization was 23%, with about 1% having anaphylactic reactions. There were at least eight IgE-binding proteins in P. chinensis venom, with 1 major allergen binding 85% of patient sera. P. chinensis venom was also found to be possibly crossreactive with bee venom, but not with imported-fire-ant venom. In Australia, anaphylactic reactions to ant stings are usually caused by the 'jack jumper' ant (Myrmecia pilosula) or the bull ant (Myrmecia pyriformis). A recent study showed promising results for immunotherapy with M. pilosula venom. There have been reports of stings by other ant species in Asia and Australia, but these reports are few and sporadic. Summary The study of ant allergy in Asia is in its infancy. Clinicians in Asia need to be aware of ant stings as a cause of severe allergic reactions. Certain species that cause allergic reactions are unique to Asia and Australia and deserve further research. The allergens in the venom of the different ant species need to be identified. We should aim for improved understanding of the epidemiology of ant-sting anaphylaxis, formulation of better diagnostic tests and possibly the introduction of immunotherapeutic strategies.