Hypersensitivity to the imported fire ant. A report of 49 cases

Two South American species of the fire ant group, Solenopsis richteri and Solenopsis invicta, now occupy more than 150 million acres in 13 southern states and cause systemic allergic reactions to their stings. We report 49 cases of such reactions with case reports and documentation. Specificity of the sting was documented by either typical pustule formation or positive skin tests. Of 37 patients treated with hyposensitizing injections, 10 have subsequently been restung. Only one suffered a systemic reaction. Problems of cross-reactivity with other insects are discussed and the literature is reviewed. Hypersensitivity to the imported fire ant continues to be a serious problem in the southern United States and appears to be amenable to properly instituted hyposensitization therapy.