Key Questions to Ask a Patient Experiencing an Anaphylactic Reaction
When evaluating a patient with suspected anaphylaxis, you must immediately assess the severity of the reaction and identify potential triggers to guide appropriate management. The history is the most important tool to determine whether a patient has had anaphylaxis and the cause of the episode 1.
Initial Assessment Questions (During Acute Reaction)
Symptom Assessment
- What symptoms are you experiencing right now?
- Respiratory: Difficulty breathing, shortness of breath, wheezing, throat tightness
- Skin: Hives, rash, flushing, itching, swelling (especially lips, tongue, face)
- Cardiovascular: Dizziness, lightheadedness, chest pain, palpitations
- Gastrointestinal: Nausea, vomiting, abdominal pain, diarrhea
Timing and Onset
- When did your symptoms begin?
- How quickly did the symptoms develop? (Rapid onset suggests more severe reaction 1)
- Have the symptoms been getting better, worse, or staying the same?
Potential Triggers
- What were you doing just before the symptoms started?
- Have you eaten anything in the last 2 hours? If so, what?
- Have you taken any medications today? (Including over-the-counter drugs)
- Have you been stung by an insect?
- Have you been exposed to latex products?
- Have you had any new exposures (foods, medications, environments)?
Previous History
- Have you ever had a similar reaction before?
- Do you have any known allergies?
- Do you carry an epinephrine auto-injector?
- If yes, have you used it for this reaction?
Detailed Follow-up Questions (After Initial Treatment)
Previous Allergic Reactions
- Have you had previous allergic reactions? How severe were they?
- What triggered your previous reactions?
- How were your previous reactions treated?
- Did you experience a delayed or biphasic reaction after previous episodes?
Risk Factors
- Do you have asthma or other respiratory conditions?
- Do you have heart disease?
- Are you taking any beta-blockers or ACE inhibitors?
- Do you have a history of mastocytosis or other mast cell disorders?
Medication History
- What prescription medications do you take regularly?
- What over-the-counter medications do you use?
- Do you take any supplements or herbal remedies?
Special Considerations
Location of Epinephrine Administration
If epinephrine was administered, confirm the injection site was appropriate. Injection should be in the anterolateral aspect of the thigh (vastus lateralis muscle) due to its location, size, and available blood flow 2. Avoid injection into:
- Digits, hands, or feet (risk of tissue necrosis)
- Buttocks (risk of Clostridial infections)
- Small muscles like the deltoid 2
High-Risk Patients
Pay particular attention to patients with:
- Heart disease (cardiac arrhythmias, coronary artery disease)
- Hyperthyroidism
- Parkinson's disease
- Diabetes mellitus
- Pheochromocytoma
- Elderly individuals
- Pregnant women 2
Documentation Requirements
For patients who will need specialist referral, collect detailed information about:
- Exact timing of symptom onset in relation to potential triggers
- All drugs and agents the patient was exposed to before the reaction
- Complete list of symptoms experienced
- Response to treatments administered 1
Pitfalls to Avoid
- Delayed recognition: Anaphylaxis can present without skin symptoms in up to 10% of cases.
- Underestimating severity: The more rapidly anaphylaxis develops, the more likely it is to be severe and potentially life-threatening 1.
- Missing biphasic reactions: Always ask about previous episodes of symptom recurrence after initial improvement.
- Incomplete trigger identification: Remember that up to 20% of anaphylactic reactions have unidentified triggers 3.
- Overlooking medication-related causes: Medications are among the most common triggers of anaphylaxis 3.
Remember that prompt recognition of signs and symptoms of anaphylaxis is crucial. If there is any doubt, it is generally better to administer epinephrine 1.