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

Abstract

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

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

Methods: 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.

Results: 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.

Conclusions: 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.

Figure 1

Types of stinging insect hypersensitivity reactions in children (<17 years) vs. adults.