Lifetime Probability of Experiencing Anaphylaxis

Anaphylaxis, a severe and potentially life-threatening allergic reaction, has a lifetime prevalence of approximately 1.6-5.1% in the United States. The incidence has more than doubled over the past 20 years, with an estimated 200,000-500,000 episodes per year resulting in about 1,500 deaths. Anaphylaxis accounts for approximately 500,000 emergency department visits annually.

The most common triggers are foods (about 33% of cases, with peanuts, tree nuts, shellfish, milk, and eggs leading), medications (about 20%, with antibiotics and NSAIDs most common), insect stings (about 18%), and latex (about 4%). In about 20% of cases, no trigger is identified (idiopathic anaphylaxis).

Anaphylaxis symptoms can progress rapidly: skin reactions (hives, itching, flushing) occur in about 90% of cases, respiratory symptoms (throat swelling, wheezing) in 70%, cardiovascular symptoms (dizziness, low blood pressure) in 45%, and gastrointestinal symptoms in 45%. Epinephrine is the only first-line treatment and should be administered immediately. Delays in epinephrine use are the primary factor in anaphylaxis deaths. All individuals with known anaphylaxis triggers should carry two epinephrine auto-injectors at all times.