Multicenter real-world experience with epinephrine 0.5 mg dosing for anaphylaxis with allergen immunotherapy

Aim: To determine the safety and efficacy of 0.5 mg intramuscular (IM) epinephrine for the treatment of subcutaneous allergen immunotherapy induced anaphylaxis. Patients & methods: Retrospective chart review of patients who received 0.5 mg of IM epinephrine for treatment of anaphylaxis from subcutaneous allergen immunotherapy at two outpatient allergy and immunology practices. Results: Thirty-eight patients received 0.5 mg IM epinephrine. Eleven patients (29%) required a second dose, and two patients (5%) required a third dose of IM epinephrine. Sixteen patients (42%) were transferred to the emergency department with ongoing symptoms. All had eventual resolution of anaphylaxis. There were no adverse reactions or fatalities. Conclusion: IM epinephrine at a dose of 0.5 mg is safe and effective for treatment of anaphylaxis from subcutaneous allergen immunotherapy. Lay abstract The aim of this study to understand whether a 0.5 mg dose of epinephrine injected into the muscle is safe and effective in treating anaphylaxis (a life-threatening allergic reaction) caused by subcutaneous allergen immunotherapy (allergy shots). We reviewed the charts of all patients who received 0.5 mg of epinephrine at two allergy clinics. Thirty-eight patients received 0.5 mg of epinephrine. Twenty-nine percent of patients required a second dose of epinephrine and 5% required a third dose. Forty-two percent of patients were sent to the emergency department due to ongoing symptoms. Anaphylaxis was successfully treated in all patients. There were no side effects or deaths. Epinephrine at 0.5 mg is safe and effective in treating anaphylaxis from subcutaneous allergen immunotherapy.