Comparison of central and peripheral airway involvement before and during methacholine, mannitol and eucapnic hyperventilation challenges in mild asthmatics.

Introduction: Testing for airway hyperresponsiveness with indirect stimuli as exercise or mannitol has been proposed to better reflect underlying airway inflammation, as compared with methacholine (MCh), believed to act directly on airway smooth muscle cells.

Objective: To investigate whether different direct and indirect stimuli induces different patterns of obstruction, recorded as central and peripheral resistance, and to see whether baseline resistance could predict a positive response to direct or indirect provocation.

Methods: Thirty-four mild asthmatics and 15 controls underwent MCh, mannitol and eucapnic voluntary hyperventilation (EVH) challenge tests.

Allergic rhinitis with hyper-responsiveness differ from asthma in degree of peripheral obstruction during metacholine challenge test.

Allergic rhinitis (AR) is a risk factor for developing clinical asthma. Moreover, AR is often associated with bronchial hyper-responsiveness (BHR). The aim of this study was to compare the degree of involvement of the peripheral airways during metacholine (MCh) challenge test in asthmatics and patients with AR with or without BHR by using the impulse oscillometry (IOS) technique.

Allergic rhinitis with or without concomitant asthma: difference in perception of dyspnoea and levels of fractional exhaled nitric oxide.

Background/aim: Allergic rhinitis (AR) is a risk factor for developing clinical asthma. Moreover, AR is often associated with bronchial hyper-responsiveness (BHR). The aim of the present study was to investigate whether patients with AR and asthma differed from AR with or without BHR in degree of perception of dyspnoea and airway inflammation, measured as fractionated exhaled nitric oxide (NO).