Bucca C, Rolla G, Brussino L, De Rose V, Bugiani M
Department of Clinical and Biological Sciences, University of Torino, Italy.
Lancet. 1995 Sep 23;346(8978):791-5. doi: 10.1016/s0140-6736(95)91617-2.
Patients with asthma-like symptoms may not have asthma but obstruction of the extrathoracic airway (EA). To evaluate if dysfunction of the EA causes asthma-like symptoms, we assessed bronchial and EA responsiveness to inhaled histamine in 441 patients who presented with at least one of three key symptoms--cough, wheeze, dyspnoea--but had neither documented asthma nor bronchial obstruction. The histamine concentrations causing a 20% fall in forced expiratory volume in 1 s (PC20FEV1) and a 25% fall in maximal mid-inspiratory flow (PC25MIF50) were used as respective thresholds of bronchial and EA responsiveness. Values 8 mg/mL or less indicated bronchial (B-HR) or EA hyper-responsiveness (EA-HR). The influence of concurrent upper respiratory tract diseases, such as post-nasal drip (PND), pharyngitis, laryngitis and sinusitis, was also assessed. We found four response patterns to the histamine challenge: EA-HR in 26.5% of the patients, B-HR in 11.1%, combined EA-HR and B-HR in 40.6%, and no-HR in 21.8%. Cough was reported by 79% of the patients, wheeze by 53%, and dyspnoea by 40%. Patients with cough as the sole presenting symptom (34.2%), as compared with those with wheeze and/or dyspnoea (20%), had significantly greater probability of having EA-HR (OR 5.35, 95% CI 3.25-8.82) and lower probability of having B-HR (OR 0.45, CI 0.28-0.70); patients with cough plus wheeze and/or dyspnoea (45.8%) had significantly greater probability of having both EA-HR and B-HR than either those with cough alone (OR 2.48, CI 1.49-4.13), or those with wheeze and/or dyspnoea but not cough (OR 1.74, CI 1.36-2.22). EA-HR alone or combined with B-HR was strongly associated with EA diseases, particularly pharyngitis and PND. Cough was significantly associated with PND, either when it was the sole symptom (OR 2.16, CI 1.14-4.09) or when it was combined with wheeze and/or dyspnoea (OR 3.53, CI 1.97-6.33). Our results suggest that extrathoracic airway dysfunction may account for asthma-like symptoms, particularly chronic cough. This abnormality seems to be sustained by chronic diseases of the upper respiratory tract.
有哮喘样症状的患者可能并非患有哮喘，而是存在胸外气道（EA）阻塞。为评估EA功能障碍是否会导致哮喘样症状，我们在441例至少出现咳嗽、喘息、呼吸困难这三种关键症状之一，但既无哮喘记录也无支气管阻塞的患者中，评估了支气管和EA对吸入组胺的反应性。引起第1秒用力呼气量下降20%（PC20FEV1）和最大吸气中期流速下降25%（PC25MIF50）的组胺浓度分别用作支气管和EA反应性的阈值。8mg/mL或更低的值表明支气管高反应性（B-HR）或EA高反应性（EA-HR）。我们还评估了同时存在的上呼吸道疾病的影响，如鼻后滴漏（PND）、咽炎、喉炎和鼻窦炎。我们发现对组胺激发试验有四种反应模式：26.5%的患者为EA-HR，11.1%为B-HR，40.6%为EA-HR和B-HR合并存在，21.8%为无高反应性（no-HR）。79%的患者报告有咳嗽，53%有喘息，40%有呼吸困难。以咳嗽为唯一症状的患者（34.2%），与有喘息和/或呼吸困难的患者（20%）相比，发生EA-HR的可能性显著更高（比值比[OR]5.35，95%置信区间[CI]3.25 - 8.82），而发生B-HR的可能性更低（OR 0.45，CI 0.28 - 0.70）；有咳嗽加喘息和/或呼吸困难的患者（45.8%）发生EA-HR和B-HR合并存在的可能性显著高于单独咳嗽的患者（OR 2.48，CI 1.49 - 4.13），或有喘息和/或呼吸困难但无咳嗽的患者（OR 1.74，CI 1.36 - 2.22）。单独的EA-HR或与B-HR合并存在与EA疾病密切相关，尤其是咽炎和PND。咳嗽与PND显著相关，无论是作为唯一症状时（OR 2.16，CI 1.14 - 4.09）还是与喘息和/或呼吸困难合并存在时（OR 3.53，CI 1.97 - 6.33）。我们的结果表明，胸外气道功能障碍可能是哮喘样症状的原因，尤其是慢性咳嗽。这种异常似乎由上呼吸道的慢性疾病所维持。
