Safety of rush immunotherapy to multiple aeroallergens in an adult population

Background: Rush immunotherapy has many potential benefits but a higher incidence of systemic reactions compared with traditional immunotherapy. The safety of rush immunotherapy to multiple aeroallergens has not been widely studied. Objective: To examine the safety of rush immunotherapy to multiple aeroallergens in a primarily adult population and to identify risk factors for systemic reactions. Methods: A retrospective review of 65 patients who received rush immunotherapy to multiple aeroallergens in a university-based allergy practice was conducted. All patients were premedicated with prednisone, cetirizine, ranitidine, and zafirlukast or montelukast. Percutaneous skin testing was performed, major allergen content was analyzed in every fourth patient's immunotherapy extract, and systemic reactions were graded. Results: Systemic reactions were observed in 25 patients (38%). All systemic reactions occurred with the final 3 doses of the protocol. Most (72%) occurred after the final dose of the protocol. Nineteen (76%) of the reactions were mild, 5 (20%) were moderate, and 1 (4%) was severe. Systemic reactions were associated with a higher degree of skin test sensitivity and the presence of weed or dog allergen in the extract (vaccine). Conclusions: Rush immunotherapy is associated with a relatively high incidence of systemic reactions, but most reactions are mild and easily treated. The degree of skin sensitivity to the allergens administered and the presence of dog or weed allergen in the extract may be predictors for the development of systemic reactions.