RATIONALE: Current subcutaneous aeroallergen immunotherapy (SCIT) guidelines recommend decreasing 50 to 90% for the initial doses of refill vials, often with several subsequent weekly visits to return to maintenance dosing. Waibel, et al (2014) published a rapid build-up (RBU) method for refill vials of 50% of maintenance dose followed by the second 50% 30 minutes later. We sought to further assess the validity of this approach and analyzed additional potential risk factors.
METHODS: A retrospective chart review was performed on 242 active SCIT patients. We analyzed the number of RBU refill SCIT performed and documentation of associated systemic reactions. Additional factors included a history of asthma, aeroallergen content of SCIT, duration of maintenance therapy, and prior systemic reactions.
RESULTS: Of 242 SCIT patients, 48 (20%) received RBU with refill vials at least once. 11 patients completed 2-5 RBU. All patients underwent at least one traditional schedule refill of maintenance vial. Of the RBU patients, 17 (35%) had asthma and 9 (19%) had a history of prior systemic reaction to SCIT therapy. Content of SCIT varied from one aeroallergen to prescriptions with trees, grasses, weeds, mold, dust mite, cockroach, dog, cat and horse.
CONCLUSIONS: We observed no increased incidence in systemic reactions from a RBU approach to SCIT refill vials compared to traditional refill approaches. While our sample size is small, our results did not appear to be affected by a history of asthma, previous systemic reactions or the content of SCIT. Larger studies are needed to better characterize this method.