Assessment of Allergic Reactions Practice Questions

25 multiple-choice questions on Assessment of allergic reactions for paramedic and EMT students, from Chapter 26 (Immunologic Emergencies). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

25 practice questions

1. Anaphylaxis is highly likely when skin signs are accompanied by:

   1. A. A long history of seasonal allergies
   2. B. A mild headache
   3. C. Mild itching confined to the sting site
   4. D. Respiratory compromise or hypotension
   Show answer

   Answer: D. Respiratory compromise or hypotension

   Acute skin or mucosal symptoms plus breathing difficulty or low blood pressure meet the clinical criteria.

2. Regarding skin findings in anaphylaxis, which statement is correct?

   1. A. Hives are present in every case
   2. B. Skin signs mean the reaction is mild
   3. C. Up to 20% of cases have none
   4. D. A rash appears before any other sign
   Show answer

   Answer: C. Up to 20% of cases have none

   Skin or mucosal signs are absent in a minority of cases, particularly when shock develops quickly. Do not wait for hives before treating a patient whose airway, breathing, or circulation is involved after an exposure.

3. After exposure to a known allergen, which finding alone is enough to treat as anaphylaxis?

   1. A. Sneezing
   2. B. Hypotension
   3. C. Watery eyes
   4. D. Local itching
   Show answer

   Answer: B. Hypotension

   Low blood pressure after exposure to a known allergen meets the criteria even without skin signs.

4. In a patient with dark skin, hives and flushing can be hard to see. To find skin signs of an allergic reaction, you should:

   1. A. Feel for welts and look at the lips
   2. B. Rely on the pulse oximetry reading instead
   3. C. Assume that skin signs are not present
   4. D. Check the palms and soles first
   Show answer

   Answer: A. Feel for welts and look at the lips

   Redness is less visible on darker skin, but hives are raised and can be felt, and swelling of the lips, tongue, eyelids, and mucous membranes is easy to see. Ask about itching too. Pulse oximetry says nothing about skin signs.

5. A patient with an allergic reaction reports a lump in the throat. This suggests:

   1. A. A typical anxiety reaction
   2. B. Esophageal spasm
   3. C. Developing airway edema
   4. D. Acid reflux from vomiting
   Show answer

   Answer: C. Developing airway edema

   Throat tightness, difficulty swallowing, and voice changes are early signs of upper airway swelling.

6. Flushing in an allergic reaction is caused by:

   1. A. Constriction of skin vessels
   2. B. A surge of adrenaline
   3. C. Fever from a skin infection
   4. D. Vasodilation in the skin
   Show answer

   Answer: D. Vasodilation in the skin

   Histamine dilates skin vessels, causing redness and warmth. Constricted skin vessels and a surge of adrenaline make the skin pale, not flushed.

7. Why should you look inside the mouth of a patient with an allergic reaction?

   1. A. To look for a hidden foreign body there
   2. B. To check for a bitten tongue
   3. C. To check for tongue or uvula swelling
   4. D. To judge how moist the mucosa is
   Show answer

   Answer: C. To check for tongue or uvula swelling

   Swelling of the tongue, lips, or uvula warns of airway compromise. A bitten tongue points to a seizure, and checking mucosal moisture assesses hydration. Neither is the reason to look in the mouth in an allergic reaction.

8. Pulse oximetry in an anaphylactic patient with severe bronchospasm may show:

   1. A. A falsely high SpO2
   2. B. No change from baseline
   3. C. Readings above 100%
   4. D. Falling SpO2
   Show answer

   Answer: D. Falling SpO2

   Severe bronchospasm impairs gas exchange. Low readings can also reflect poor perfusion.

9. A patient with hives after a bee sting becomes confused and drowsy. This change most likely means:

   1. A. The venom has reached her brain
   2. B. Her blood pressure is likely falling
   3. C. She is reacting to the antihistamine
   4. D. Normal fatigue after a scare
   Show answer

   Answer: B. Her blood pressure is likely falling

   New confusion or drowsiness during an allergic reaction suggests the brain is not getting enough blood, a sign of shock. Check the BP and treat as anaphylaxis. Bee venom does not act directly on the brain, no antihistamine has been given, and a change in mental status should never be written off as fatigue.

10. A patient with throat tightness and a changing voice after eating shrimp has an SpO2 of 98%. This reading:

    1. A. Does not rule out airway danger
    2. B. Rules out airway swelling for now
    3. C. Means epinephrine can be delayed
    4. D. Shows the reaction is resolving
    Show answer

    Answer: A. Does not rule out airway danger

    Oxygen saturation stays normal until the airway is nearly closed. Throat tightness and voice change are early signs of laryngeal swelling and call for IM epinephrine now. A normal SpO2 is not reassurance.

11. The most important question to ask a patient with a suspected allergic reaction is:

    1. A. When did you last eat a meal?
    2. B. Have you ever smoked tobacco?
    3. C. What were you exposed to, and when?
    4. D. What medications are you taking now?
    Show answer

    Answer: C. What were you exposed to, and when?

    Identifying the trigger and timing helps estimate severity and prevents further exposure.

12. Which history finding most increases concern for a severe reaction?

    1. A. Prior anaphylaxis to the same trigger
    2. B. Seasonal hay fever every spring
    3. C. A family history of eczema or asthma
    4. D. Mild hives once as a young child
    Show answer

    Answer: A. Prior anaphylaxis to the same trigger

    Prior anaphylaxis predicts future severe reactions.

13. A patient who has already used an epinephrine auto-injector before you arrive should:

    1. A. Be released once symptoms improve on scene
    2. B. Still be assessed and transported
    3. C. Receive no further treatment
    4. D. Be told to rest at home
    Show answer

    Answer: B. Still be assessed and transported

    Symptoms can return as the epinephrine wears off or with a biphasic reaction.

14. Which symptom often precedes anaphylaxis and should not be dismissed?

    1. A. Ringing in the ears
    2. B. Slow, deep breathing
    3. C. Feeling drowsy and relaxed
    4. D. A sense of impending doom
    Show answer

    Answer: D. A sense of impending doom

    Many patients report anxiety or a feeling that something terrible is happening. Ringing in the ears suggests a drug effect such as salicylate toxicity, and early anaphylaxis brings fast breathing and agitation rather than slow breathing or calm drowsiness.

15. Hypotension in an adult with anaphylaxis is defined as systolic BP below:

    1. A. 130 mmHg
    2. B. 90 mmHg
    3. C. 120 mmHg
    4. D. 110 mmHg
    Show answer

    Answer: B. 90 mmHg

    A drop of more than 30% from baseline also counts.

16. In infants and children, an early sign of anaphylaxis may be:

    1. A. High fever with chills
    2. B. Bradycardia with facial flushing
    3. C. Sudden behavior change, irritability
    4. D. A purple rash that does not blanch when pressed
    Show answer

    Answer: C. Sudden behavior change, irritability

    Young children cannot describe symptoms. Persistent crying or lethargy may be the first signs. High fever and a nonblanching purple rash suggest infection such as meningococcemia, not anaphylaxis, and bradycardia is a late, ominous sign in children rather than an early one.

17. Which finding helps distinguish anaphylaxis from a vasovagal reaction after an injection?

    1. A. Bradycardia and pallor
    2. B. Brief fainting only
    3. C. Rapid recovery when supine
    4. D. Tachycardia and hives
    Show answer

    Answer: D. Tachycardia and hives

    Vasovagal syncope causes bradycardia and pale skin. Anaphylaxis causes tachycardia and flushing or hives.

18. Which condition can mimic anaphylaxis with wheezing but lacks skin signs and hypotension?

    1. A. Asthma exacerbation
    2. B. Septic shock from pneumonia
    3. C. Hypoglycemic reaction
    4. D. Acute ischemic stroke
    Show answer

    Answer: A. Asthma exacerbation

    Asthma causes wheezing without hives, swelling, or shock. Exposure history helps.

19. The scene may provide clues to the allergen, such as:

    1. A. An empty insulin pen in the trash
    2. B. A carbon monoxide alarm sounding in the hall
    3. C. A home oxygen tank by the bed
    4. D. Medication bottles or insect nests
    Show answer

    Answer: D. Medication bottles or insect nests

    Look for food wrappers, new medications, or stinging insects. An insulin pen points to hypoglycemia, a carbon monoxide alarm points to poisoning, and home oxygen points to chronic lung disease. Each is a useful clue, but not to an allergen.

20. A man stung on the hand has hives on his chest and back. This finding means the reaction is:

    1. A. Systemic, not just local
    2. B. A large local reaction
    3. C. Venom toxicity from one sting
    4. D. Contact dermatitis from his shirt
    Show answer

    Answer: A. Systemic, not just local

    Hives away from the sting site show that mediators are acting throughout the body, so the reaction is systemic. Look closely for airway, breathing, circulation, or GI involvement, which would make it anaphylaxis. A single sting does not cause venom toxicity.

21. Why should you record the exact time of each epinephrine dose, including any the patient gave himself?

    1. A. To bill the patient for the dose
    2. B. Because epinephrine is a scheduled drug
    3. C. To time repeat doses and observation
    4. D. To decide when antihistamines may start
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    Answer: C. To time repeat doses and observation

    The time of the last dose tells you when a repeat dose may be due and lets the hospital time the observation period for a biphasic reaction. Epinephrine is not a controlled substance, and antihistamines do not have to wait for it.

22. A man swallows a wasp that was in his soda can and is stung inside the mouth. He has no allergy history and only mild throat pain now. You should:

    1. A. Release him, since he is not allergic
    2. B. Watch closely for airway swelling
    3. C. Have him drink more soda to rinse
    4. D. Induce vomiting to remove the wasp
    Show answer

    Answer: B. Watch closely for airway swelling

    A sting in the mouth or throat can cause local swelling that threatens the airway even without allergy, and an allergic reaction is still possible. Monitor the airway and transport for observation. Vomiting does not help and risks aspiration.

23. The primary assessment priority in a patient with an allergic reaction is:

    1. A. Skin color
    2. B. Medication history
    3. C. Airway
    4. D. Allergen identification
    Show answer

    Answer: C. Airway

    Airway swelling can progress quickly. Assess and manage the airway first.

24. For a 6-year-old in anaphylaxis, systolic hypotension is defined as a BP below about:

    1. A. 70 mmHg
    2. B. 90 mmHg
    3. C. 100 mmHg
    4. D. 82 mmHg
    Show answer

    Answer: D. 82 mmHg

    For children 1 to 10 years old, hypotension is a systolic BP below 70 + (2 x age in years), here 70 + 12 = 82 mmHg. A drop of more than 30% from baseline also counts. The adult cutoff of 90 would overcall it, and 70 is the cutoff for infants.

25. A man says his peanut reactions have been 'just hives' in the past. After eating peanuts today he has hives again. Regarding how severe this reaction may become, you should assume:

    1. A. It will be mild like before
    2. B. It could still become severe
    3. C. It will resolve without care
    4. D. Hives mean the airway is safe
    Show answer

    Answer: B. It could still become severe

    The severity of past reactions does not reliably predict the next one; a patient with only skin symptoms before can still develop anaphylaxis. Monitor closely for airway, breathing, circulation, and GI signs and be ready with epinephrine. Hives say nothing about the airway.