Anaphylaxis due to Pachycondyla goeldii ant: a case report.

Most cases of anaphylaxis caused by ants are attributed to ants from the Solenopsis genus [1] but there are many ant species of different genera and their distribution around the world varies. In Brazil, where there are over 2000 catalogued species of ants, all the cases of ant-induced anaphylaxis reported to date have been attributed to Solenopsis species [2,3]. We describe the fi rst case of anaphylaxis caused by Pachycondyla goeldii, an ant from the Ponerinae subfamily. A 52-year-old man developed anaphylaxis after being stung on the hand by an unidentifi ed insect while removing grass from his garden. He felt a tingling sensation and developed generalized urticaria and shortness of breath. He received treatment for anaphylactic shock at the emergency department and recovered within a few hours. Five days later, the patient had recovered completely. At the site of the sting, there was a dark spot surrounded by a red ring. He was receiving treatment for diabetes and hypertension (glimepiride, metformin, and enalapril [5 mg/day]) and he stated that he had not taken any other drugs or eaten any unusual foods. The patient reported that he had been stung twice (40 and 15 days previously) by a black insect like a wasp on his shoulder, which had become swollen and painful. No Solenopsis ants or wasps nests were found during a visit to the patient’s house but black ants measuring 1 cm in length (and popularly known as gambá) were found in the garden. The ants were identifi ed as P goeldii by the Center for the Study of Social Insects (CEIS) at São Paulo State University. The venom was obtained by removing the venom reservoirs with microscissors and squeezing the content into twicedistilled water. The crude venom solution was then lyophilized and maintained at –20oC until needed. The investigation of specifi c immunoglobulin E (IgE) in the patient’s serum (ImmunoCAP, Phadia Uppsala, Sweden) yielded positive results for Solenopsis invicta (class 3) and negative results for Vespula species, Polistes species and Apis mellifera. The total IgE was 49 IU/mL. A positive intradermal skin test was observed with P goeldii venom at a concentration of 0.1 μg/mL and with S invicta extract (IPI-ASAC Laboratory São Paulo, Brazil) at a concentration of 10 μg/mL. The tests performed in 2 nonatopic healthy controls were negative up to 10 μg/mL for both venoms. The venom of P goeldii was subjected to two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis, with the detection of approximately 45 proteins, with a molecular weight of 10 to 66 kDa and an isoelectric point of between 4 and 10 (Figure, A). Immunoassays with the patient’s serum revealed 4 IgE-reactive spots of between 30 and 45 kDa (Figure, B).