Methacholine bronchial hyperresponsiveness in chronic sinusitis

The coexistence of chronic sinusitis (CS) may deteriorate the clinical cond ition of lower airway diseases such as bronchial asthma (BA) or chronic bro nchitis (CB). However, the bronchial hyperresponsiveness (EH) in CS without any apparent lower airway disease is not fully understood nor are the effe cts of treatment. We examined lower airway hyperresponsiveness to methachol ine (MCh) in 42 subjects with CS but without allergic rhinitis (AR) who had normal lung functions without any pulmonary symptoms, comparing it with th at of 50 subjects with stable BA, 50 subjects with simple CB and 40 subject s with AR,and further examined the effect of endoscopic sinus surgery in 7 CS subjects with BH. The BH to MCh was measured in terms of the minimum dos e (Dmin), defined as the cumulative dose at the point where respiratory con ductance began to decrease. A Dmin <50 units was defined as BH, Seventy-one percent of CS subjects showed BH. without relation to the severity or dura tion of CS, or atopic status. BH in CS subjects, which was less than that i n BA subjects, was similar to that in simple CB or AR in both its prevalenc e and degree. After the surgical treatment of CS, EH significantly decrease d (p < 0.01) with improvements in both nasal symptoms and sinus lesions. Th ese findings suggest that CS itself induces BH to a degree similar to simpl e CB and AR without any relationship to the clinical background, and that a dequate treatment of CS reduces BH.