Outpatient Emergencies: Anaphylaxis.

Anaphylactic fatalities are rare; however, mild reactions can rapidly progress to cardiovascular and respiratory arrest. The clinical course of anaphylaxis can be unpredictable. Prompt and early use of epinephrine should be considered. Most anaphylaxis episodes have an immunologic mechanism involving immunoglobulin E (IgE). Foods are the most common cause in children; medications and insect stings are more common in adults. When the cause is not completely avoidable or cannot be determined, a patient should be supplied with autoinjectable epinephrine and be instructed its use. They should keep the device with them at all times and taught the signs and symptoms of anaphylaxis.