Multiple epinephrine doses for stinging insect hypersensitivity reactions treated in the emergency department

Data are sparse on epinephrine treatment for stinging insect hypersensitivity (SIH) reactions.

To establish the frequency of receiving more than 1 dose of epinephrine in patients presenting to the emergency department (ED) with SIH reactions.

We performed a medical record review of all 153 patients with SIH reactions presenting to 3 EDs in Boston, Massachusetts, between January 1, 2001, and December 31, 2006. Patients were identified by International Classification of Diseases, Ninth Revision (ICD-9) codes (989.5, 995.0, and 995.3). We focused on clinical presentations and treatments, including epinephrine treatments given before and during the ED visit.

The cohort was 54% male, with a median age of 33 years. Bees were the most frequently reported triggering insect (74%). A total of 59% of patients experienced large local reactions, whereas 36% had systemic reactions (10% cutaneous systemic and 26% anaphylaxis). The remaining 5% presented with normal local reactions to insect stings. Among patients with systemic reactions, 82% were stung within 3 hours of arrival at the ED. Most (60%) received treatments before arrival at the ED, including 26% who received epinephrine. While in the ED, these patients received antihistamines (76%), systemic corticosteroids (55%), and epinephrine (9%). Overall, 35% of patients with systemic reactions received epinephrine, and among this subset, 16% received more than 1 dose. Most patients with systemic reactions (67%) were discharged to home. At ED discharge, 68% received a prescription for self-injectable epinephrine, but only 11% had documentation of referral to an allergist.

Among patients with systemic SIH reactions who received epinephrine, 16% received a second dose. Physicians should consider prescribing 2 doses of self-injectable epinephrine for patients at risk for systemic SIH reactions.