[Characterization of patients with ant sting allergy: a 9 case serie and immunotherapy response].

Background: Ant sting allergy can trigger from local cutaneous manifestations to fatal anaphylaxis, last one with an incidence of 23.5% in adults. Immunotherapy is effective in 9798% of cases to reducing the frequency and severity of these reactions, to reduce the risk of anaphylaxis to 5% compared to 60% in patients without immunotherapy.

Objective: Describe the clinical characteristics, course, and response to specific immunotherapy in patients with ant sting allergy.

Methods: A retrospective, observational, and descriptive study was conducted in nine patients with allergic reactions to ant stings from 2017 to 2025. Age, sex, history of atopy, type of reaction, skin testing, and clinical course were analyzed.

Results: The mean age was 37.8 years (range 1159), with a female predominance (66.7%). Of the patients, two (22.2%) had local reactions and seven (77.8%) had systemic reactions, including two cases of anaphylaxis. Thirty-three percent (33.3%) had a history of allergic rhinitis, and 22.2% had an allergy to other insects. Five patients received immunotherapy; during follow-up, none presented systemic reactions after re-exposure, and one patient had a mild cutaneous reaction without requiring hospitalization.

Conclusion: A high frequency of systemic reactions was observed in patients allergic to ant venom, exceeding that reported in the literature. Immunotherapy reduced the severity of reactions after re-exposure. Ant venom immunotherapy is effective in reducing the severity of allergic reactions and the risk of anaphylaxis during future exposures, being the only treatment shown to modify the natural history of the disease.