Allergen immunotherapy shows short-term benefits, according to a meta-analysis reported by Physician’s Briefing. 

The researchers observed a reduction in short-term symptom and medication scores, with evidence found for publication bias. No reduction was seen in short-term combined medication and symptom scores; a beneficial long-term effect was seen in one study.

Subcutaneous immunotherapy correlated with improved quality of life and reduction in allergen-specific airway hyperreactivity (AHR); this was not seen for sublingual immunotherapy (SLIT). No consistent effects were seen on asthma control, exacerbations, lung function, or non-specific AHR. There was a modest increase in the risk of adverse events with AIT. Evidence on cost-effectiveness was mainly available for SLIT, which was likely to be cost-effective.