Characteristics of venom allergy at initial evaluation: Is fire ant hypersensitivity similar to flying Hymenoptera?

Hymenoptera venom allergy (HVA) is a well-established cause of anaphylaxis; however, studies comparing patients with imported fire ant (IFA) to flying hymenoptera (FH) allergies are lacking.

This study sought to characterize the initial presentation and examine differences between patients with IFA and FH reactions.

A multiyear (2007-2014), observational, single-institution analysis of patients referred for evaluation of HVA was performed. Data was obtained via physician interview, chart review and specific IgE results.

175 patients were enrolled with no difference between FH and IFA patients when analyzing mean age, sex or likelihood to seek emergency department (ED) care. Asthma was similar in all groups at 21%. ED treatments were also similar (epinephrine: 32/150, 21%; antihistamines: 141/155, 91%; corticosteroids: 67/148, 45%). Reaction severity correlated with likelihood of ED visit (P <.001), use of epinephrine (P <.001) and corticosteroid use (P <.05). Patients presenting to the ED with anaphylaxis received epinephrine in 27/73 (37%) of cases. Overall, 149/175 (85%) patients in our cohort were confirmed to be sensitized to hymenoptera. Of those with positive testing 127/149 (85%) chose to pursue VIT.

IFA and FH patients have many similarities at presentation. Asthma occurred 2.5 times more frequently our cohort compared to the general US population. Epinephrine administration in our cohort was suboptimal. Children have initial reactions and are treated in the ED similarly to adults, with a notable (although not statistically significant) reduced use of epinephrine. The majority of patients seen in the ED and subsequently followed up in an allergy clinic had their venom allergy confirmed and initiated life-saving immunotherapy.