Name: Anaphylaxis — bulletproof documentation — ER Toolkit
Creator: Kim Trinh, MD

Anaphylaxis is a clinical diagnosis treated with one drug, given fast. The defensible chart shows which diagnostic criterion was met, that epinephrine was first-line and not delayed for antihistamines, and that the patient left with an auto-injector and a plan.

01What's at stake

Up to half of anaphylaxis deaths occur within the first hour, and epinephrine is consistently under-used and delayed. The two classic misses: not recognizing anaphylaxis because there's no rash (skin findings are absent in 10%–20%), and reaching for diphenhydramine or steroids first while the patient deteriorates. The record should make clear you treated anaphylaxis as anaphylaxis.

02Diagnostic criteria (any one = anaphylaxis)

Acute skin/mucosal involvement plus respiratory compromise or hypotension/end-organ symptoms.
Two or more of {skin/mucosal, respiratory, hypotension, persistent GI symptoms} rapidly after a likely allergen.
Hypotension after a known allergen (adults SBP <90 or >30% drop).

Isolated hypotension or syncope after a known allergen is anaphylaxis — even with no rash. Anaphylactic shock usually has reflex tachycardia and wide pulse pressure (unlike vasovagal bradycardia); beta-blocked patients may not mount a tachycardia.

03History & exam

Trigger and timing; what EMS/caregivers already gave (≈20% need a second epinephrine dose in the ED). → redosing
Asthma, prior severe reaction, nut allergy — higher risk of severe/fatal course. → high risk
Chronic beta-blocker use — blunts epinephrine; may need glucagon. → refractory
Airway red flags: hoarseness, lingual/oropharyngeal edema, stridor → early airway management. → airway
ACE-inhibitor angioedema is bradykinin-mediated and often not epinephrine-responsive — but don't withhold epinephrine if an allergic cause is plausible.

Skip the typing

Work the case in the Allergic Reaction Workup — it records the criteria met, the airway assessment, the observation period, and the discharge auto-injector plan, and assembles an MDM that shows anaphylaxis was recognized and treated first-line.

04Management — epinephrine first

IM epinephrine 0.3–0.5 mg of 1:1000 into the anterolateral thigh (peds 0.01 mg/kg, max 0.3 mg); repeat every 5–10 min as needed. No absolute contraindications — the benefit outweighs the risk even in older or cardiac patients.
Don't delay for adjuncts. H1+H2 antihistamines and corticosteroids are second-line — they treat skin symptoms, not shock or airway, and the evidence that steroids prevent biphasic reactions is weak.
Refractory / cardiovascular collapse → IV epinephrine infusion; large-bore fluids (adults 500–1000 mL bolus), supine with legs up; glucagon 1–2 mg IV for beta-blocked patients.
Airway — anticipate the difficult airway (oropharyngeal/laryngeal edema); consider awake/fiberoptic approaches over routine RSI.

05Observation & discharge

Biphasic reactions occur in ~5%–20%, typically ~8–10h later. Observe most patients ~4–6h after resolution; admit those needing IV epinephrine/glucagon or with airway involvement or high-risk features.
Prescribe an epinephrine auto-injector (ideally two) with hands-on teaching — even if symptoms fully resolved; labels alone are insufficient.
Short course of H1+H2 antihistamines, allergen avoidance, return precautions, and PCP + allergist referral.

06What to document

▼ weak

"Allergic reaction. Benadryl and solumedrol given, improved. Discharged."

▲ defensible

"Anaphylaxis — urticaria plus wheeze and dyspnea after peanut exposure (≥2 systems). IM epinephrine 0.3 mg to the lateral thigh at 1408, ~3 min after recognition; H1/H2 blockers and fluids as adjuncts; symptoms resolved. No airway edema. Observed 5h without biphasic recurrence. Discharged with two epinephrine auto-injectors and hands-on teaching, 3-day antihistamines, return precautions, and allergy referral."

07Where charts fail

Not diagnosing anaphylaxis because there's no rash, or calling a post-allergen syncope "vasovagal."
Giving antihistamines/steroids first and delaying epinephrine.
Choosing IV over IM epinephrine for a stable patient (arrhythmia risk).
Assuming one EMS dose is enough — redose for persistent compromise.
Discharging without an auto-injector, teaching, and referral.

08Sources

Singer E, Zodda D. Allergy and anaphylaxis: principles of acute emergency management. Emergency Medicine Practice (EB Medicine). 2015;17(8).
Sampson HA, Muñoz-Furlong A, Bock SA, et al. Symposium on the definition and management of anaphylaxis: summary report. J Allergy Clin Immunol. 2005;115(3):584-591.
Lieberman P, Nicklas RA, Oppenheimer J, et al. The diagnosis and management of anaphylaxis practice parameter: 2010 update. J Allergy Clin Immunol. 2010;126(3):477-480.
Simons FER, Ardusso LR, Bilò MB, et al. International consensus on (ICON) anaphylaxis. World Allergy Organ J. 2014;7(1):9.
Kemp SF, Lockey RF, et al. Epinephrine: the drug of choice for anaphylaxis — WAO statement. World Allergy Organ J. 2008;1(7 Suppl):S18-S26.

Anaphylaxis: documentation that holds up