Stinging insect allergy.

Systemic allergic reactions to insect stings are estimated to occur in about 1 percent of children and 3 percent of adults. In children, these reactions usually are limited to cutaneous signs, with urticaria and angioedema; adults more commonly have airway obstruction or hypotension. Epinephrine is the treatment of choice for acute anaphylaxis, and self-injection devices should be prescribed to patients at risk for this allergic reaction. Stinging insect allergy can be confirmed by measurement of venom-specific IgE antibodies using venom skin tests or a radioallergosorbent test. Patients with previous large local reactions have a 5 to 10 percent risk of experiencing systemic reactions to future stings. Patients with previous systemic reactions have a variable risk of future reactions: the risk is as low as 10 to 15 percent in those with the mildest reactions and in some children, but as high as 70 percent in adults with the most severe recent reactions. Because of demonstrated efficacy (98 percent), venom immunotherapy is recommended for use in patients who are at risk for severe systemic reactions to future insect stings. Venom immunotherapy is administered every four to eight weeks for at least five years. Immunotherapy may be needed indefinitely in patients at higher risk for recurrence of anaphylaxis after treatment is stopped.