Observational study of the safety of an ultra-rush sublingual immunotherapy regimen to treat rhinitis due to house dust mites.

BACKGROUND Ultra-rush regimens for administering sublingual immunotherapy to patients with allergies are becoming more widespread. We aimed to assess treatment safety for patients with allergic rhinitis with or without asthma caused by Dermatophagoides house dust mites. METHODS This observational study at 5 Spanish centers included 218 patients aged 4-64 years, of whom 117 were women and 122 were under 15 years old. Ultra-rush regimen consisted of incremental doses of an allergen extract comprising a 50% mixture of Dermatophagoides pteronyssinus and Dermatophagoides farinae (30, 60, 120, 240 IR every 30 min) followed by maintenance therapy. Adverse reactions were monitored and asthmatic patients underwent spirometric testing at baseline and after each dose. Follow-up was scheduled after 2 weeks of maintenance with 240 IR three times a week. RESULTS Five patients had to modify ultra-rush regimen because of mild local adverse reactions. In total, 32 adverse reactions were reported in 27 patients during the ultra-rush regimen. Seven of these events were local gastrointestinal reactions, and the remaining 17 were local reactions, mainly labial or mouth itching and burning. Eight events were systemic reactions [rhinitis (n = 3), general malaise (n = 1), general malaise and vomiting (n = 1), dizziness (n = 1), asthma (n = 1), dyspnea (n = 1)]. All adverse reactions were mild or moderate. Serious adverse events or life-threatening anaphylactic reactions were not reported. CONCLUSIONS High-dose sublingual immunotherapy with Dermatophagoides allergen extracts can be safely administered in an ultra-rush regimen, although its usefulness and benefit for perennial allergens (e.g. house dust mites) must be evaluated.