The effectiveness of intranasal corticosteroids in combined allergic rhinitis and asthma syndrome.

Background: Allergic rhinitis (AR) and asthma often coexist and may represent two manifestations of the same disease recently named combined AR and asthma syndrome (CARAS).

Objective: To review the common pathophysiology of combined AR and asthma and to investigate the efficacy of intranasal corticosteroids (INCS).

Methods: Medline was used to identify articles relevant to mechanisms. A Cochrane systematic review was performed to assess the efficacy of INCS in CARAS.

Results: There is cross-talk, evidence of a common inflammatory response in both sites, linked by a systemic component. The efficacy of anti-inflammatory INCS on asthma outcomes was assessed in a systematic review of 12 randomized controlled trials involving 425 subjects. After INCS there were non-significant trends for improvement in asthma symptom score (standardized mean difference (SMD) of 0.61; P=0.07), forced expiratory volume in 1 s (SMD of 0.31; P=0.08), and morning peak expiratory flow (weighted mean difference of 36.51; P=0.06). There was no impact on methacholine airways responsiveness (SMD of -0.20; P=0.4). The review identified two promising new treatment options in united airway disease such as INCS as monotherapy in rhinitis and mild asthma, and a combined intranasal and intrabronchial corticosteroid (IBCS) deposition technique.

Conclusions: Common mucosal inflammatory responses occur in CARAS. This systematic review shows trends for a benefit of INCS in CARAS, but recognizes that more research is needed. At this stage, the current best practice is to treat asthma conventionally with IBCS with or without beta(2)-agonist and to add INCS to improve specific rhinitis symptoms.