Evaluation of the effectiveness of subcutaneous immunotherapy using birch pollen extract for pollen-food allergy syndrome

Abstract

Backgrounds: Recently, patients with oral allergy syndrome (OAS) to fruits or vegetables caused by pollen-food allergy syndrome (PFAS) have increased nationwide. We examined effectiveness of SCIT using birch pollen extract for PFAS. Methods: A total of 19 patients (9 male and 10 female) underwent SCIT with birch pollen extract from August 2011 to August 2016. Rush schedule was used for the initial updosing for SCIT in a hospital setting. In maintenance phase, SCIT was administered every 4-8 weeks on an outpatient basis. According to the situation of sensitization, patients underwent SCIT with other extracts at the same time. Oral food challenge (OFC) with fruits and vegetables was performed at baseline and after rush phase. We also investigated about OAS symptoms in maintenance phase. Results: SCIT was remarkably effective in five patients for OAS symptoms just after rush phase, and effective in nine patients. And it was not effective in two patients, and not determined in three patients, but it was confirmed to be effective in four out of these five patients in maintenance phase. There were relapse of OAS symptoms in three patients, then SCIT was remarkably effective or effective in 15 patients (79%) in maintenance phase. No patients dropped off the SCIT protocol. Conclusions: Generally, PFAS cant be expected to remit naturally. SCIT with birch pollen extract effectively reduces OAS symptoms, and it can be expected as a radical therapy for PFAS.