When Can Immunotherapy for Insect Sting Allergy Be Stopped?

Background: Stings by Hymenoptera (honey bees, vespids, ants) can cause systemic allergic reactions (SARs). Venom immunotherapy (VIT) is highly effective and reduces an allergic patient's risk of a recurrent SAR to less than 5-20%. The risk of a recurrent SAR to a re-sting decreases the longer VIT is continued. The recommended duration of VIT is at least 3 to 5 years. Risk factors: Risk factors for recurrent SARs to a sting after stopping VIT have been identified and discussed: •older age•concomitant cardiac and pulmonary disease•mast cell disorders, elevated baseline serum tryptase•severe reactions before VIT•SARs during VIT to treatment injections or stings•repeated stings after VIT.Recommendations concerning stopping VIT: For patients without any of the identified risk factors, VIT should be continued for 5 rather than 3 years. In patients with definite risk factors, a longer duration of VIT has to be discussed before stopping it. In mast cell disorders, VIT for life is recommended. Because of the residual risk of SARs after VIT, all patients are advised to carry an epinephrine autoinjector indefinitely and to continue to take measures to avoid Hymenoptera stings.