Explanation to Question 4
Fatal and near-fatal anaphylaxis typically occurs in people with known food allergy at locations away from home (such as school). Of note, persons with asthma and teenagers are at a higher risk for fatal reactions. Many people with food allergy do not carry self-injectable epinephrine with them. Food antigens may not be apparent in foods such as cookies or cakes, and even trace amounts of the food or handling of the food can induce anaphylaxis.
Common symptoms of anaphylaxis include dyspnea, urticaria, angioedema, flushing, pruritus, GI symptoms, syncope, and hypotension. Cutaneous symptoms are the most common and occur in over 90% of reported cases but are less common in cases of fatal anaphylaxis. Signs of anaphylaxis typically occur within seconds to minutes after exposure to the allergen, although, rarely, symptoms may occur a few hours later. A late phase reaction may also occur several hours after the initial reaction. Parents should be advised that any child with signs of anaphylaxis needs observation in a healthcare setting for a minimum of 4-6 hours.
Epinephrine should be given at the first sign of anaphylaxis. Epinephrine acts by decreasing vasodilation, edema, and bronchoconstriction. In addition, it suppresses the release of inflammatory mediators from mast cells and basophils. Patients should be taken to the closest hospital even if the symptoms have resolved as they may recur and the patient would then require additional doses of epinephrine.
Antihistamines may control urticaria or other symptoms of anaphylaxis but its use should not be substituted for intramuscular epinephrine. Diphenhydramine and cetirizine can be used in addition to epinephrine but both medications have a slower onset of action and should never be used alone for the treatment of anaphylaxis.
All patients with food allergy should wear a MedicAlert bracelet listing the foods that cause allergic reactions.
The correct answer is B, epinephrine is the primary treatment for anaphylaxis.