DURATION OF VENOM IMMUNOTHERAPY - RELATIONSHIP TO THE SEVERITY OF SYMPTOMS OF INITIAL INSECT STING ANAPHYLAXIS

Background: This study assessed the postulate that the adequate duration of venom immunotherapy (VIT) is related to the seventy of the initial sting anaphylactic symptoms. Methods: Data were collected from patients with venom allergy who had sting anaphylaxis and subsequent positive venom skin test results, received maintenance VIT, and had field re-stings after cessation of VIT. There were 217 re-stings in 113 patients with 15 systemic reactions in 10 patients (a re-sting reaction rate of 9% per sting and 7% per patient). Results: Re-sting reactions occurred in 1 of 25 patients with initial mild anaphylaxis (4%), 2 of 41 patients with moderate reactions (5%), and 7 of 47 patients with initial severe symptoms (15%). The results were not influenced by the duration of VIT or the interval between cessation of VIT and the re-sting. Eighteen patients who converted to negative skin test reactions had no reactions when re-stung Conclusions: These results suggest a relationship between the severity of anaphylaxis and subsequent duration of VIT Two to three years is sufficient for patients who had mild to moderate anaphylaxis. Longer duration of therapy is advisable for patients who had severe symptoms and continue to have positive venom skin test results.