Published online: January 12, 2018
Allergic rhinitis is the fifth leading chronic disease in the Unites States. Allergen subcutaneous immunotherapy (SCIT) has been used for more than a century and is recommended for patients with allergic rhinitis, allergic conjunctivitis, and/or asthma who have significant symptoms despite therapy, experience unacceptable side effects from medications, or desire to reduce the long-term use of medications. SCIT is considered overall a safe therapeutic modality. However, it may lead to systemic allergic reactions (SR) as reported recently from longitudinal surveillance in North America with a rate 0.1% to 0.2% per injection-visit.
Recently, in The Journal of Allergy and Clinical Immunology: In Practice Albuhairi et al reported the rate of SRs to standardized SCIT in pediatric patients aged 5 to 18 years in a retrospective chart review. Two groups were compared: group 1 (N=124) started SCIT within a period extending from January 2009 to June 2012, whereas group 2 (N=118) started SCIT within a period extending from January 2013 to June 2016. The protocol was modified in group 2 so that doses were adjusted in the spring for tree and grass pollen and in the fall for weed pollen. An Excel program was generated to perform dose calculation for allergen mixture and glycerin volumes in pharmacy so that across patients, vials of the same dilutions contained the same concentration for specific allergens regardless of allergen mixtures.
The rate of SR per injection visit was 0.429% in group 1 and 0.364% in group 2. There was no significant difference in the rate or severity of SR in the 2 groups with no-fatal or near-fatal SR noted. Asthma was a significant risk factor in the younger age subgroup aged 5 -11 years.
Protocol modification did not lead to a significant drop in SR. In the younger age group, asthma was a significant risk factor for SR. Larger multicenter studies are required to further evaluate the safety and efficacy of standardized SCIT, the impact of dose adjustment during pollen season, and the presence of demographic risk factors in the pediatric age group.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.