Review Contra Costa County EMS Guideline A04, focusing on recognizing and treating allergic reactions and anaphylaxis. This episode differentiates mild from moderate/severe reactions, emphasizing the critical role of thorough assessments and timely epinephrine administration, particularly with airway involvement. Discuss proper epinephrine dosing, special considerations for patients over 50 or with cardiac histories, and adjunct treatments such as oxygen and diphenhydramine. Clinical pearls address nuances of anaphylaxis, epinephrine techniques, and conditions that mimic severe allergic reactions.