Effectiveness of VIT
The effectiveness of VIT can solely be monitored by the outcome of sting challenges or field stings. Sting challenges were performed in 18 patients; 192 patients experienced field stings within the first year of the maintenance phase. In total, 210 (17.7%) patients were stung, and 91.0% of patients tolerated the sting without systemic symptoms. Thirty-four (16.2%) patients suffered from a LLR. Of the patients with SSR, 12 experienced a grade I reaction, and among these, two took β-blockers. Five patients had a grade II reaction, and one of them took a β-blocker, while two had a Grade III reaction, and one patient took a β-blocker. None of the patients with therapy failure took an ACEI. 191 patients tolerated the sting; among these, 20 (10.5%) took a β-blocker, 23 (12.0%) an ACEI, and 10 (5.2%) both drugs. Taking antihypertensive drugs did not increase the risk for therapy failure (p=0.72).