Anaphylaxis Secondary to Aeroallergen Immunotherapy in a Military Member.

We present the case of a 43-year-old active-duty US Air Force service member who experienced an anaphylactic reaction during routine aeroallergen immunotherapy. The patient had a long-standing history of perennial and seasonal allergic rhinoconjunctivitis, with confirmed sensitization to multiple environmental allergens through skin prick and serum-specific IgE testing. He tolerated build-up immunotherapy until reaching the 0.4 mL injections from the maintenance 1:1 volume/volume (1:100 weight/volume) vials, at which point he developed an anaphylactic reaction characterized by vomiting, hypotension, and respiratory distress. He required three intramuscular doses of epinephrine and was transferred to the emergency department. This case underscores the complexities of allergy management in military personnel, particularly those receiving immunotherapy in preparation for deployment. The patient's severe systemic reaction raises important considerations regarding risk stratification, protocol modification, and implications for operational readiness. Although he was deemed fit for duty after stabilization, this event highlights how environmental allergen exposure and immunotherapy-related complications can impact force health protection. Proactive allergy screening, patient education, and emergency preparedness, especially ensuring access to and proper use of epinephrine auto-injectors, remain essential components of pre-deployment medical planning. This case reinforces the importance of individualized immunotherapy protocols, vigilant monitoring for systemic reactions, and comprehensive contingency planning within military healthcare systems.