Accelerated Immunotherapy: Why Are We Going So Slow?
Purpose of review
Accelerated schedules for administering subcutaneous aeroallergen immunotherapy have the potential to provide convenience, reduce the cost, and improve compliance over conventional (weekly) schedules. In this review, we describe studies of cluster and rush immunotherapy (RIT), the risk of systemic allergic reactions (SARs) for various schedules, and methods to reduce that risk.
Cluster schedules are associated with a slightly increased risk of a SAR that can be reduced by taking an H1 antihistamine on the day of injections. The risk of a SAR can also be reduced with depo extracts, fewer injections per cluster, and administration of fewer than 3 clusters per week. RIT is associated with a 27 to 38% risk of a SAR that can be reduced with administration of corticosteroids, an H1 and H2 antihistamine and possibly a leukotriene blocker for 3 days prior to the procedure and by stopping at a lower dose. Reactions tend to occur 1–2 h after the last injection on the day of RIT, and there is an increased risk of a reaction if subsequent weekly doses are missed.
Accelerated immunotherapy schedules can offer benefits over weekly schedules; however, the increased risk of a SAR needs to be considered when deciding to recommend such a schedule.
Current Treatment Options in Allergy
Van Mason, J., Portnoy, J. Accelerated Immunotherapy: Why Are We Going So Slow? Current Treatment Options in Allergy 6, 396-409 (2019).