1) Recognize anaphylaxis
Treat as anaphylaxis if there is a likely trigger plus any of:
- Skin/mucosal symptoms: hives, flushing, angioedema
- Respiratory compromise: wheeze, stridor, throat tightness, hypoxemia
- Circulatory compromise: hypotension, syncope, collapse
- Severe GI symptoms: repetitive vomiting, crampy abdominal pain
2) Call for help, stop exposure, position the patient
- Remove the trigger if possible
- Call emergency response / activate code
- Lay patient supine with legs elevated if tolerated
- If vomiting or pregnant: left lateral position
- Avoid sudden standing/walking
3) Give epinephrine immediately, IM in the mid-outer thigh
This is first-line treatment. Do not delay.
Adults
- 0.3 to 0.5 mg IM or intramuscular . It is not always one and one. Repeating the epinephrine shot is not rare.
- Use 1 mg/mL (1:1000) epinephrine
- This equals 0.3 to 0.5 mL IM
- Repeat every 5 to 15 minutes if symptoms persist or worsen
Children
Use 0.01 mg/kg IM of 1 mg/mL (1:1000) epinephrine into the mid-outer thigh
- Max single dose often 0.3 mg in smaller children
- In larger adolescents/adults, some protocols allow up to 0.5 mg
Practical dose ranges:
- 0.1 mg for very small infants/young children in some protocols
- 0.15 mg for children about 10–25 kg
- 0.3 mg for children/adolescents about 25–30 kg and above
- 0.5 mg may be used in larger adolescents/adults per protocol
If using prefilled auto-injectors, match the device to the child’s weight per local labeling.
4) Airway, breathing, circulation support
- Give high-flow oxygen if hypoxemic, in respiratory distress, or if severe reaction
- Place on monitor if available
- Obtain IV access if moderate/severe reaction, hypotension, or need for fluids
IV fluids for hypotension/shock
Use isotonic crystalloid
- Adults: 1–2 L rapid bolus, reassess, repeat as needed
- Children: 20 mL/kg bolus, repeat as needed for shock
5) Again, Repeat epinephrine if needed
If symptoms are not improving or recur:
- Repeat IM epinephrine every 5–15 minutes
6) Bronchospasm treatment
If wheeze/bronchospasm persists after epinephrine:
- Albuterol (salbutamol) inhaled
- Adults: standard nebulized dose per local formulary
- Children: weight/age-based nebulized dosing per local formulary
This is adjunctive, not a substitute for epinephrine.
7) Additional medications
These are adjuncts only and should not delay epinephrine.
H1 antihistamine
May help hives/itching, but does not treat airway or shock.
- Example: diphenhydramine per age/weight-based dosing or local protocol
Corticosteroid
Often given, though onset is delayed and benefit for preventing biphasic reactions is uncertain.
- Example: prednisone / methylprednisolone / dexamethasone per local protocol
8) Reassess frequently
Watch for:
- Persistent wheeze or stridor
- Hypotension
- Recurrent vomiting
- Progressive swelling
- Need for airway intervention
9) Escalate if severe or refractory
Consider advanced airway management and critical care if:
- Stridor, impending airway obstruction
- Refractory hypotension despite repeated IM epinephrine and fluids
- Altered mental status or collapse
10) Observe before discharge
Observation time depends on severity and response; longer observation is needed for:
- Severe reactions
- Need for multiple epinephrine doses
- Hypotension
- Asthma
- Poor social support or distant access to care
11) Discharge planning
If appropriate for discharge:
- Prescribe epinephrine auto-injectors. I suggest refills. Why? If in a panic, locating them may be hard, but not if they are in five close locations.
- Teach use and return precautions
- Arrange allergy follow-up
- Identify and avoid trigger if possible
Quick dosing summary
Epinephrine IM (1 mg/mL, 1:1000)
- Adults: 0.3–0.5 mg IM q5–15 min PRN
- Children: 0.01 mg/kg IM q5–15 min PRN
- typical max per dose often 0.3 mg in smaller children
- up to 0.5 mg in larger adolescents/adults depending on protocol
Fluids
- Adults: 1–2 L isotonic crystalloid bolus
- Children: 20 mL/kg isotonic crystalloid bolus