Resolution of Debilitating Large Local Reaction from Imported Fire Ant Stings with Rush Immunotherapy: A Case Report

Abstract

Although treatment of systemic reactions with both flying Hymenoptera and imported fire ant (IFA) with immunotherapy is the standard of care, immunotherapy is currently not recommended for the perceived relatively minor hazard of large local reactions. However, some large local reactions can be debilitating, resulting in severe swelling, pain and discomfort as well as loss of function of an extremity. The objective of this study was to evaluate whether rush immunotherapy (RIT) with IFA whole-body extract can prevent debilitating large local reactions to the sting of the IFA. An 8-year-old boy with debilitating large local reactions to the sting of IFAs underwent a 2-day RIT protocol with IFA whole-body extract. Sting challenges were performed before, 30, and 90 days after RIT. The area of the wheal and flare were measured at 1-hour post-sting and the area of induration at 24 hours. There was a 96% increase in the 1-hour post-sting wheal at 1 month but a 60% decrease from baseline at 3 months post-RIT. The 1-hour flare was increased by 63% at 1 month but reduced by 16% from baseline at 3 months post-RIT. Induration at 24 hours was reduced by 26% at 1-month post-RIT and by 94% by 3 months. The patient tolerated RIT and the sting challenges without complications. We conclude that RIT may be effective in significantly attenuating the magnitude of debilitating, large local reactions from the sting of the IFA. (Pediatr Asthma Allergy Immunol 2000;14[4]333–338.)