CHARACTERISTICS OF VENOM ALLERGY AT INITIAL EVALUATION

Abstract

Introduction This study sought to characterize the initial presentation of hymenoptera venom allergic (HVA) patients and examine differences between patients with imported fire ant (IFA) and flying hymenoptera (FH) reactions. Methods A multi-year, observational, single-institution analysis of patients referred for evaluation of HVA was performed. Data was obtained via physician interview and chart review including baseline characteristics, comorbid conditions, medications, culprit stinging insect, reaction severity, treatments, emergency department (ED) interventions and specific IgE results. Results 175 patients were enrolled (mean age 28yrs ±14yrs; 44% males, 77/175). Of these, 21.7% (38/175) reacted to FH, 70.9% (124/175) to IFA and 7.4% (13/175) to both. There was no difference between FH and IFA patients when analyzing mean age, sex or likelihood to seek ED care. Asthma was similar in all groups and noted in 20.6% (36/175). The most common presentation was cutaneous plus another system and was similar in all groups; 114/175 (65%). ED treatments were similar in all groups and included epinephrine (32/150, 21%), antihistamines (141/155, 91%) and corticosteroids (67/148, 45.3%). Reaction severity correlated with likelihood of ED visit (p=0.0005), use of epinephrine (p=0.0002) and corticosteroid use (p=0.03). Patients presenting to the ED with anaphylaxis received epinephrine in 37% (27/73) of cases. Patients seen in ED whose venom allergy was confirmed was 68.3% (71/104), 91.5% of whom went on to initiate life-saving immunotherapy. Conclusions IFA and FH patients have many, now confirmed, similarities. The severity of HVA reactions correlated with ED visits, use of epinephrine and corticosteroids; however only 37% of patients with anaphylaxis received epinephrine.