Are Large Local Reactions Useful to Predict Future Anaphylaxis to Hymenoptera Stings?

Abstract

Unaware of the natural history of large local reactions caused by Hymenoptera stings, patients and clinicians are often concerned when faced with these reactions. These concerns include the difficulty in avoiding stings, the local discomfort, and the fear that the local reaction portends systemic, potentially life-threatening subsequent reactions. This review presents the historical studies that have assessed the natural history of large local reactions caused by Hymenoptera stings and, in doing so, provides rationale for the current consensus guidelines for the management of these reactions. Retrospective and prospective studies in both adult and pediatric populations have provided insight into the natural history of large local reactions caused by Hymenoptera stings dating back to the 1980s. Each of these studies has demonstrated a low risk of future systemic allergic reactions or anaphylaxis in patients with a history of large local reactions. No clinical biomarker exists to determine the severity of future Hymenoptera sting reactions. Without a reliable clinical biomarker to identify those at risk for systemic allergic reactions or anaphylaxis, recommendations on the management of Hymenoptera sting reactions are derived from retrospective and prospective studies reviewed in this article. These studies provide strong evidence describing a low risk of future systemic allergic reactions or anaphylaxis in patients who have a history of large local reactions. Referral to an allergy specialist can provide reassurance for the referring clinicians and patients with a history of large local reactions. Treatment of large local reactions involves symptom relief with cold compresses, over-the-counter analgesics, oral antihistamines, and occasionally topical or oral glucocorticoids, usually reserved for very large, protracted reactions. Given the low risk of systemic allergic reactions and anaphylaxis, venom or imported fire ant whole body extract immunotherapy is not recommended for patients with a history of large local reactions. However, there may be some cases where the clinician considers providing an epinephrine autoinjector and/or venom or imported fire ant whole body extract immunotherapy for reasons other than future systemic allergic reactions or anaphylaxis risk. In any case, shared decision-making between the patient and clinician should take place with appropriate documentation of the risks and benefits.