D2.344 - National Data on Anaphylaxis in Brazil: Findings from the Brazilian Registry

Anaphylaxis is a severe, immediate and potentially fatal multisystem allergic reaction. There is a need for greater knowledge about the epidemiology of anaphylaxis to improve its management and prevention.

This is an update from the Brazilian Anaphylaxis Registry of the Brazilian Association of Allergy and Immunology. This online registry contained demographic data, suspected triggers, clinical manifestations, treatment and diagnostic tests. Data were evaluated from June 2021 until February 2026. The study was approved by the Ethics Committee of the Pensi Institution. Statistical analysis was performed using Jamovi software.

We evaluated 406 patients (211 female; 51.9%), mean age 26.3 yo (median 22 yo). Among the total, 179 were children/adolescents (<18 yo); 207 adults (18-64 yo) and 20 elderly people (65-93 yo). There was a predominance of males among children (56.9%) and females among adults (58.9%; p=0.006). The most common triggers were foods, drugs, and Hymenoptera stings. Among foods, the most frequent were cow's milk (13.8%); shellfish (6.2%); eggs (5.2%); wheat (2.7%) and peanuts (3.9%). The most frequent drugs were NSAIDs (8.4%), biological agents (8.4%), and antibiotics (3.7%). Among hymenoptera stings, the most frequent were bee stings (7.6%), ants (7.4%) and wasps (6.6%). Latex was responsible for 11 cases. The anaphylactic reaction occurred more frequently at home (196/406; 48.3%). Biphasic anaphylaxis was observed in 17 patients (4.2%). Regarding diagnostic tests, 27 (6.7%) performed serum tryptase measurement. Regarding treatment, 212 (52.2%) received epinephrine by a professional and 28 (6.9%) via autoinjector. Only 48 patients carried the autoinjector. Antihistamines were used by 88.2%, corticosteroids (76.6%), bronchodilators (28.8%), oxygen therapy (29.3%) and fluid resuscitation (30.5%). Eighteen patients were intubated and ten were resuscitated. Two patients died: one from a bee sting and the other from an ant bite. Neither of them had an epinephrine auto-injector.

The most frequent triggers were foods, drugs and Hymenoptera stings, respectively. The use of epinephrine remains suboptimal in Brazil, while 3rd line treatments such as antihistamines and corticosteroids are used by most patients. There was a gender difference in the pediatric and adult age groups. Most anaphylactic events occurred at home, highlighting the importance of adequate patient education and the epinephrine autoinjector.