Question 1

Can anaphylaxis occur without skin involvement?

Accepted Answer

Yes — up to 20% of anaphylaxis cases present without urticaria or angioedema. These 'cutaneous-negative' cases are more common in food-induced anaphylaxis (especially in children), insect venom anaphylaxis, and exercise-induced anaphylaxis. Absence of skin symptoms should not delay epinephrine administration.

Question 2

What is biphasic anaphylaxis and how should it be monitored?

Accepted Answer

Biphasic anaphylaxis is the recurrence of symptoms 1–8 hours (rarely up to 72 hours) after initial resolution, without re-exposure to the trigger. It occurs in 1–20% of cases. Risk factors include: severe initial reaction, delayed epinephrine, multiple doses of epinephrine, and oral allergen ingestion. Observation for 6–8 hours after symptom resolution is recommended.

Question 3

When should IM epinephrine be administered?

Accepted Answer

Immediately upon suspicion of anaphylaxis — do not wait for diagnostic confirmation. The WAO guidance is clear: any patient meeting anaphylaxis criteria should receive IM epinephrine (1:1000, 0.01 mg/kg, max 0.5 mg in adults, 0.3 mg in children) into the anterolateral thigh. Delay in epinephrine is the strongest predictor of anaphylaxis mortality.

Question 4

Who should be prescribed an epinephrine auto-injector?

Accepted Answer

Patients who have experienced anaphylaxis (food, venom, or idiopathic), patients with mastocytosis or mast cell activation syndrome, and patients with food allergy AND asthma (especially if poorly controlled). Prescribe at least two auto-injectors and provide a written anaphylaxis action plan. Education on proper use and allergen avoidance is essential.