SCIT effective for controlling hayfever symptoms
MedWire News: Allergen-specific subcutaneous immunotherapy (SCIT) is as effective as pharmacotherapy for controlling the symptoms of seasonal allergic rhinitis (SAR), a review of published studies suggests.
SCIT is usually considered a "second-line" treatment for SAR in patients with symptoms that are insufficiently controlled with pharmacotherapy, those who do not want to be on constant or long-term pharmacotherapy, and those in whom pharmacotherapy induces undesirable side effects, explain Paolo Maria Matricardi (Charité Medical University, Berlin, Germany) and team.
They add that pharmacotherapy reduces symptoms of allergic rhinitis without modifying its natural history, whereas SCIT ameliorates symptoms associated with the subsequent exposure to the causative allergen.
To compare the efficacy of SCIT and pharmacotherapy for controlling SAR symptoms, the team searched the literature for meta-analyses that included five or more randomized, double-blind, placebo-controlled trials of SCIT or pharmacotherapy in patients with SAR.
In total, four meta-analyses that included 42 trials containing data on total nasal symptom score (TNSS), total symptom score (TSS), or both during the first pollen season after treatment initiation were included in the final analysis.
Efficacy was determined as the percentage reduction in TSSs and TNSSs obtained with active treatment compared with placebo, calculated as the relative clinical impact (RCI) and the standardized mean difference (SMD) of treatment verses placebo (effect size [ES]).
Analysis of the pooled data revealed that the mean weighted RCI of SCIT on TNSS was greater than that of mometasone and montelukast, at -34.7% versus -31.7% and -6.3%, respectively.
They also found that the weighted mean RCI of SCIT on TSSs was greater than that of desloratadine, at -32.9% versus -12.0%.
The overall ES of SCIT regarding TNSS was similar to that of mometasone, at SMDs of -0.94 and -0.47, respectively, but greater than that of montelukast, at an SMD of -0.24.
Regarding TSS, the overall ES of SCIT was comparable with that of desloratadine, at SMDs of -0.86 and -1.00, respectively.
Matricardi and colleagues conclude in the Journal of Allergy and Clinical Immunology: "Our data provide indirect evidence that SCIT is an antisymptomatic treatment in patients with SAR, which is at least as potent as drugs, even in the first season of treatment.
They add: "Trials directly comparing the antisymptomatic effect of pharmacotherapy versus SCIT in patients with SAR are needed to confirm this indirect evidence."
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By Mark Cowen