IMPORTED FIRE ANT HYPERSENSITIVITY: A 1-DAY RUSH IMMUNOTHERAPY SCHEDULE WITHOUT PREMEDICATION

Imported fire ants (IFAs), which now reside in much of the southern part of the United States, are a frequent cause of hypersensitivity reactions, being the reason for 42% to 54% 1,2 of insect hypersensitivity evaluations performed in these endemic areas. Conventional IFA immunotherapy (IT) schedules, given in the insect hypersensitivity practice parameter, comprise 25 to 28 injections to reach the maintenance dose, which could take more than 3 to 6 months. 3 Unique to IFAs is the difficulty with practicing effective avoidance measures, 4 with annual sting rates up to 58% in people residing in endemic areas. 5 Patients sensitive to IFAs are, therefore, at considerable risk of continued systemic reactions to stings during the months of IT buildup by conventional schedules. We believe these issues, which are unique to IFAs, make rush IT schedules an important option to consider for those patients allergic to IFA stings. In the only published trial of IFA rush IT, Tankersley et al 6 reported on a highly successful and safe 2-day IFA rush IT regimen. After continuing to experience ongoing success with this 2-day regimen, we attempted to shorten the rush period to a single day. We believed this could lessen patient inconvenience and time away from work, reduce costs, and make it a more attractive option for more patients. Because a significant benefit to medication pretreatment was not found using the prior 2-day IFA rush protocol, it was not used in the current protocol. The inclusion criteria for enrollment into the study were patients aged 18 to 65 years, those with a history consistent with a systemic reaction to an IFA sting, and either a positive result to an IFA skin test or an IFA ImmunoCAP (Phadia AB, Uppsala, Sweden) specific IgE test. The protocol was approved by the Wilford Hall Medical Center (San Antonio, Texas) institutional review board. The rush protocol consisted of 10 injections being given during the