[A CASE OF ANAPHYLAXIS DUE TO STINGING OF A Brachyponera chinensis]

The case involved a man in his forties. While working at the restaurant that the patient runs, the patient experienced a stab-like pain on the left shoulder and developed systemic pruritic eruptions. He was diagnosed with anaphylaxis upon visiting our emergency department. Conjunctival hyperemia, lip swelling, cold sweats, and nausea presented later. A cap fluorescence enzyme immunoassay using the serum of the patient showed specific immunoglobulin E (IgE) positivity for wasps; therefore, we hypothesized that he had anaphylaxis caused by the insect's sting. Insects of the same species as that by which the patient had been stung were collected and finally identified as the Asian needle ant (Brachyponera chinensis). The freeze-dried insects' bodies were sonicated into powders and stored for following examinations. Next, a basophil activation test was performed using the patient's whole blood treated with the reagent above, which showed positivity. Furthermore, a skin prick test using the same reagent showed a positive result, and the reaction increased in a concentrationdependent manner. Based on these results, the patient was diagnosed with anaphylaxis after a sting by the ant. Based on the results of the allergen component specific IgE test, we speculated that the pathogens in this case was group5 allergen of the Asian needle ant. Anaphylaxis following insect stings by this ant has been reported frequently in South Korea. However, it is quite rare in Japan, although the ant is native to Japan. Clinicians should consider that this allergy can occur indoors, unlike allergies to other types of venom.

Keywords: Brachyponera chinensis; allergen component; anaphylaxis; basophil activating test (BAT); insect venom.