Anaphylaxis Epipen in ThighAnaphylaxis is one of the most under-appreciated and under-treated conditions in the Emergency Department. A common misperception is that you need hypotension to diagnose it. Below is a brief summary of the diagnostic criteria and ED treatment protocol. Immediate administration of IM epinephrine is critical.

A major challenge is deciding which patients can go home and which need to be admitted, because of the risk of “rebound” or a biphasic anaphylactic response. This may occur as late as 72 hours later, but typically occur within the first 24 hours. There isn’t a good answer for this.

What’s your practice in dispositioning these patients? Personally, I admit at least those patients who present with severe hypotension, require more than 1 epinephrine dose, or have poor social support.

NOTE: Unlike the photo on the top, warn patients NOT to rest their thumb on the device because of the risk inadvertent needle puncture.

PV Card: Anaphylaxis

Adapted from 1,2
Go to the ALiEM Cards site for more resources.

Arnold J, Williams P. Anaphylaxis: recognition and management. Am Fam Physician. 2011;84(10):1111-1118. [PubMed]
Simons FER. Anaphylaxis. Journal of Allergy and Clinical Immunology. 2010;125(2):S161-S181. doi: 10.1016/j.jaci.2009.12.981
Michelle Lin, MD
ALiEM Editor-in-Chief
Professor and Digital Innovation Lab Director
Department of Emergency Medicine
University of California, San Francisco
Michelle Lin, MD


Professor of Emerg Med at UCSF-Zuckerberg San Francisco General. Founder of ALiEM @aliemteam #PostitPearls
Michelle Lin, MD