Thank you for your inquiry.
Unfortunately, there is no definitive answer to your question. It can best be answered by copying the quote regarding this topic from the most recent guidelines on the management of hymenoptera allergy (1). This quote is copied for you below:
“The optimal duration of imported fire ant immunotherapy is less well defined. One retrospective survey suggests an equal risk of a sting reaction whether a patient received more than 3 years of immunotherapy or less than 3 years of immunotherapy, although the numbers were small .44 A survey of allergists indicated a great deal of variation in recommendations regarding the duration of immunotherapy for fire ant allergy.72 Some allergists recommend indefinite treatment. Most allergists consider stopping immunotherapy after a specified period (usually 4-5 years), either empirically or only when skin test responses become negative. Until further data are available, a definitive recommendation about the duration of immunotherapy for fire ants cannot be made.”
As you can see, based on this quote, the decision is really entirely based upon your own clinical judgment after discussing the issues involved with your patient. We simply do not have enough data to make axiomatic recommendations regarding this topic. My personal choice is usually to stop in 5 years if the reaction was not severe.
Thank you again for your inquiry and we hope this response is helpful to you.
1. Golden D, et al. Stinging insect hypersensitivity: a practice parameter update, 2011. J Allergy Clin Immunol 2011; 127(4):852-854.
Phil Lieberman, M.D.