Tracheopathia Osteoplastica Misdiagnosed as Asthma

Tracheopathia osteoplastica (TPO) is a rare disorder characterized by cartilaginous or bony mucosal nodules in the tracheobronchial tree. Due to most patients being asymptomatic, the majority are diagnosed post-mortem. If symptoms are present, they typically include chronic cough, dyspnea, hemoptysis, hoarseness, and wheezing, with some of these symptoms overlapping with asthma. This case report describes an adult female with chronic cough who was diagnosed with asthma that was refractory to therapy for 8 years. Computed tomography (CT) of the chest revealed several soft tissue masses in the trachea with bronchoscopy revealing TPO in the upper portion of the trachea. She was diagnosed with TPO and started on airway clearance and a nasal corticosteroid spray with resolution of the cough at follow-up 3 months later.     

A case of airway-limiting type relapsing polychondritis]

A 59-year-old woman was referred to our hospital for chronic cough and myalgia. Polymyalgia rheumatica (PMR) and bronchial asthma were first diagnosed, and she was prescribed 15 mg/day prednisolone. PMR improved immediately. However, her chronic cough continued, and wheezing was heard on chest auscultation. The flow-volume loop showed a severe expiratory flow limitation and a notching sign at early expiration. Diffuse thickening and narrowing at the trachea and bilateral main bronchus were shown on chest CT. On flexible bronchoscope the trachea and bilateral main bronchus collapsed on expiration. We suspected relapsing polychondritis (RP), but she had no findings of saddle nose or deformity of the external ear. Therefore, biopsy of the tracheal cartilage was done. RP was diagnosed by the modified criteria of Damiani and the histology confirmed degeneration of the tracheal cartilage. She was treated by high dose corticosteroids, and her symptoms improved. This case report emphasizes the need to consider the possibility of RP as a cause of chronic cough or intractable asthma.     

嗜酸粒细胞性气道炎症和慢性咳嗽

嗜酸粒细胞性气道炎症是以气管和支气管壁存在明显嗜酸粒细胞浸润为特征的一种病理状态.哮喘、咳嗽变异性哮喘及非哮喘性嗜酸粒细胞性支气管炎是慢性咳嗽的常见病因,嗜酸粒细胞性气道炎症是其共同病理过程,提示嗜酸粒细胞性气道炎症与慢性咳嗽的发生可能有密切联系,并呈现不同的临床表型.     

Primary tracheal carcinoma

Primary tumors of trachea are rare tumors those can be missed easily because the symptoms and signs are subtle. The diagnosis may delay or they may be misdiagnosed as chronic bronchitis or asthma. We present a 64 year-old man with dyspnea, cough, cyanosis and with a normal chest radiogram.     

Asthma survey items as predictors of respiratory problems in children 2 yrs later: a longitudinal study.

The study compared the ability of characteristics defined by an asthma survey (wheeze versus cough and asthma diagnosis versus no diagnosis) to predict later respiratory problems in a cohort of 108 schoolchildren who had reported either recent wheeze or recurrent cough in a 1987 asthma survey. The children recorded daily respiratory symptoms and peak flow from April 1989 until May 1990. The frequency and severity of lower respiratory symptom episodes and peak flow dips were compared in the wheeze and cough groups and in the diagnosed versus nondiagnosed children. The independent effects of initial wheeze, atopy, diagnosis and bronchial hyperresponsiveness (BHR) on the longitudinal outcome measures were assessed using multiple linear regression. Children with initial wheeze had more chronic symptoms and peak flow variability than those with cough alone, but wheeze had only a weak effect on frequency and severity of acute lower respiratory episodes. Children with both wheeze and atopy had more acute symptomatic episodes and more chronic symptoms than did the other children. Children with diagnosed asthma (versus no diagnosis) had significantly more frequent and severe lower respiratory exacerbations, more days symptomatic and greater peak flow variability. The predictive effects of diagnosis were independent of (and stronger than the effects of) wheeze, atopy and BHR, or combinations of these variables. The results suggest that among children who report respiratory symptoms, survey-reported wheeze on its own is a weaker marker of significant respiratory disease than is a doctor's diagnosis of asthma.     

Cough challenge tests involving mechanical stimulation of the cervical trachea in patients with cough as a leading symptom

Background and objective: Challenge tests involving chemical stimulation by inhalation of capsaicin or citric acid are currently used to assess cough sensitivity. We investigated the clinical usefulness of cough challenge tests based on mechanical stimulation. Methods: A total of 347 patients (126 men and 221 women) were enrolled in the study, including 161 patients with asthma, 116 with cough‐variant asthma, 27 with acute upper respiratory tract viral infections, 25 with acute bronchitis, four with pneumonia, three with chronic bronchitis and 11 with cough of unknown aetiology. Three modes of mechanical stimulation were assessed: the cervical trachea was compressed softly with the fingers several times (tracheal compression test); the trachea was stretched by retroflexion of the neck for 5 s (tracheal stretch test); and a vibrating tuning fork was placed on the cervical trachea for 20 s (tuning fork test). The relationships between phonation‐induced cough and the results of these tests were assessed. Results: The cough detection rate was 27.7% with the tracheal compression test, 39.8% with the tracheal stretch test and 36.9% with the tuning fork test. An itchy sensation with or without cough was noted by about 50% of subjects undergoing each of the tests. Provocation of cough and an itchy sensation during each test was significantly more frequent in subjects with phonation‐induced cough. Tests were usually negative after improvement of the cough with treatment. Conclusions: Mechanical stimulation of the cervical trachea is a feasible cough challenge test that may be useful for evaluating disease activity.     

The association of gastroesophageal reflux disease with asthma and chronic cough in the adult

Gastroesophageal reflux disease (GERD) is a common condition which is particularly prevalent in patients with asthma and chronic cough. Physiologic changes caused by asthma and chronic cough promote acid reflux. GERD is also considered by many investigators as a factor contributing to airway inflammation. An etiological relationship between GERD and asthma/chronic cough and vice versa has been supported by a large number of experimental and clinical findings and refuted by others. Although further controlled studies are needed to clarify this relationship, GERD and asthma/chronic cough appear to be linked to each other. The association of GERD with asthma and chronic cough involves nerve reflexes, cytokines, inflammatory and neuroendocrine cells and, in some patients, tracheal aspiration of refluxing gastric fluids. GERD may present with typical symptoms but can also be asymptomatic. Sensitive methods for diagnosing GERD are available, which include esophageal pH monitoring, acid provocative tests, modified barium swallow and endoscopy. Consideration of the association of GERD with asthma and chronic cough is of practical value in the management of chronic cough or asthma resistant to treatment. Treatment of GERD in patients with asthma has been consistently shown to improve respiratory symptoms but not necessarily pulmonary function tests. Surgical treatment can be a useful and cost-effective approach in selected patients with asthma and GERD.     

Narrative Review: how long should patients with cough variant asthma or non-asthmatic eosinophilic bronchitis be treated?

The causes of chronic cough can be categorized into eosinophilic and noneosinophilic disorders, and approximately 30% to 50% of people with chronic cough have eosinophilic airway inflammation, the presence of which can be confirmed by sputum eosinophilia or elevated exhaled nitric-oxide levels. Cough variant asthma (CVA) is a phenotype of asthma which lacks wheezing or dyspnea, and consistently one of the most common causes of chronic cough worldwide. CVA and non-asthmatic eosinophilic bronchitis (NAEB) shares common feature such as chronic dry cough, eosinophilic inflammation, and development of chronic airflow obstruction (CAO) and asthma in a subset of patients. The distinctive characteristic of these conditions is the presence of airway hyperresponsiveness in CVA but not in NAEB. Coughing is responsive to bronchodilators such as beta-agonists in CVA, but such feature has not been clarified in NAEB. Inhaled corticosteroids (ICSs) are the first-line treatment, and leukotriene receptor antagonists are also effective, in patients with both CVA and NAEB. This review will give an outline of clinical and physiological features, and prognosis and its determinants of CVA and EBNA. Further, the rationale and evidence, despite limited, for the need of long-term treatment will be discussed. The development of airway remodeling due to mechanical stress to the airways exerted by long-standing coughing will also be discussed.     

Extrathoracic airway responsiveness in children with asthma-like symptoms,including chronic persistent cough

Asthma-like symptoms, including chronic persistent cough, are not always specific for classical asthma. In order to investigate whether assessment of extrathoracic airway hyperresponsiveness (EAHR) during methacholine bronchial challenge helped in the evaluation of pediatric patients with asthma-like symptoms such as chronic cough, we examined 133 consecutive, unselected patients (mean age, 10.06 +/- 2.16 years) who had neither established asthma nor bronchial obstruction previously. We recorded the forced mid-inspiratory flow (FIF(50)) as an index of extrathoracic airway narrowing. In addition, a 25% decrease in FIF(50) (PD(25)FIF(50)) below the cutoff concentration of < or = 8 mg/mL methacholine was assumed to indicate EAHR. According to the methacholine response, 81 patients had EAHR, and 41 of them had combined EAHR and bronchial hyperresponsiveness (BHR); 39 patients had only BHR. Airway hyperresponsiveness was not demonstrated in 13 patients and not in any of the control children. When patients with cough as the sole presenting symptom (60.9%) were compared with those with cough and wheeze (20.3%), those with cough alone had a significantly greater probability of having EAHR (OR, 4.16; 95% CI, 1.32-13.13) and a lower probability of having BHR (OR, 0.70; CI, 0.25-1.95) than those with cough and wheeze. Patients with cough, wheeze, and dyspnea (18.8%) had a significantly greater chance of having BHR than those with cough alone (OR, 5.08; CI, 1.55-16.64). Patients with cough and wheeze as compared with those with cough, wheeze, and dyspnea had significantly greater probability of having both EAHR and BHR (OR, 4.71; CI, 1.94-11.47).In order to ascertain the clinical relevance of EAHR, we assessed in the second part of the study whether the effects of treatment of the underlying disease would result in relief of airway hyperresponsiveness. Rhinosinusitis and perennial allergic rhinitis accounted for EAHR in 71 patients, and 34 of them also demonstrated BHR. They received specific therapy for their upper airway diseases for 4 weeks. Compared with values before treatment, FIF(50) and forced expiratory volume in 1 sec (FEV(1)) did not change significantly. The dose of methacholine causing a 20% fall in FEV(1) (PD(20)FEV(1)) and PD(25)FIF(50) values were significantly increased from 2.40 +/- 1.39 to 4.22 +/- 1.13 mg /mL (P < 0.001) and from 1.03 +/- 1.75 to 8.71 +/- 1.21 mg /mL (P < 0.0001), respectively.We conclude that measurements of EAHR and BHR are the most important ways to evaluate children with asthma-like symptoms, including chronic persistent cough when chest X-rays and pulmonary function tests remain within normal limits. Therefore, empirical treatment is not necessary when these investigations are available. Our results suggest that specific treatment of inflammation in the upper airways reversed persistant cough, and may play an important role in modulating lower airways responsiveness in patients with concomitant BHR.     

Asthma in elite athletes: how do we manage asthma‐like symptoms and asthma in elite athletes?

Introduction: Asthma is frequent in elite athletes and the high prevalence of asthma might be associated with specific types of sport. It has been suggested that chronic endurance training might increase the number of neutrophils in the airways, and this may reflect airway injury. The use of anti‐asthmatic medication in elite athletes is also currently under scrutiny in order to reduce the risk of under‐treatment or over treatment. Objectives: Determine the use of anti‐asthmatic medication and the prevalence of asthma‐like symptoms and asthma in Danish elite athletes. Further, to determine whether elite athletes with asthma‐like symptoms have asthma and investigate the airway inflammation and airway reactivity to mannitol. Materials and Methods: Three cross‐sectional studies: (i) Applications for Abbreviated Therapeutic Use Exemption (ATUE) certificates in 2005 were studied (N = 694); (ii) a questionnaire survey of elite athletes (N = 418); and (iii) a clinical study of elite athletes. A total of 54 elite athletes (19 with physician‐diagnosed asthma) participated together with two control groups: (i) 22 non‐athletes with physician‐diagnosed asthma (steroid naïve for 4 weeks before the examination) and (ii) 35 non‐athletes without asthma. Examinations: questionnaires, exhaled nitric oxide (eNO), spirometry, skin prick test, mannitol test and blood samples. Induced sputum was done in subjects with asthma. Results: (i) Anti‐asthmatic medication was included in 445 (64%) of all ATUE certificates. A total of 308 (69%) elite athletes applied for inhaled corticosteroids (ICS), and most ATUE certificates were handled by general practitioners (GP) (78%). (ii) A total of 329 (79%) elite athletes completed the questionnaire; 181 (55%) reported asthma‐like symptoms and 46 (14%) had asthma. Anti‐asthmatic medication was currently taken by 24 (7%) elite athletes. Elite athletes participating in endurance sports had higher prevalences of asthma‐like symptoms (74%), use of anti‐asthmatic medication (15%) and current asthma (24%) than all other athletes (P < 0.01). (iii) No difference in lung function, eNO, airway reactivity (AR) to mannitol and atopy between elite athletes with and without asthma‐like symptoms was found. Elite athletes with physician‐diagnosed asthma had less AR [Response Dose Ratio (RDR) 0.02 (0.004) vs 0.08 (0.018) P < 0.01], and fewer sputum eosinophils [0.8% (0–4.8) vs 6.0% (0–18.5), P < 0.01] than non‐athletes with physician‐diagnosed asthma. Conclusion: Most applications for ATUE certificates were handled by GPs, and the majority concerned anti‐asthmatic medication. We found signs of under‐treatment of elite athletes with asthma, and endurance athletes had the highest prevalence of asthma‐like symptoms and asthma. The prevalence of asthma‐like symptoms was higher than the prevalence of asthma, and we showed that symptoms alone should not be used to diagnose asthma. We demonstrated that asthma‐like symptoms are independent of lung function, eNO, RDR and atopy in elite athletes. Elite athletes with physician‐diagnosed asthma seem to have less airway reactivity and fewer sputum eosinophils than non‐athletes with physician‐diagnosed asthma, but more studies are needed to further investigate if and how the asthma phenotype of elite athletes differs from that of classical asthma.     

Eosinophilic bronchitis is an important cause of chronic cough.

Eosinophilic bronchitis presents with chronic cough and sputum eosinophilia, but without the abnormalities of airway function seen in asthma. It is important to know how commonly eosinophilic bronchitis causes cough, since in contrast to cough in patients without sputum eosinophilia, the cough responds to inhaled corticosteroids. We investigated patients referred over a 2-yr period with chronic cough, using a well-established protocol with the addition of induced sputum in selected cases. Eosinophilic bronchitis was diagnosed if patients had no symptoms suggesting variable airflow obstruction, and had normal spirometric values, normal peak expiratory flow variability, no airway hyperresponsiveness (provocative concentration of methacholine producing a 20% decrease in FEV(1) ([PC(20)] > 8 mg/ml), and sputum eosinophilia (> 3%). Ninety-one patients with chronic cough were identified among 856 referrals. The primary diagnosis was eosinophilic bronchitis in 12 patients, rhinitis in 20, asthma in 16, post-viral-infection status in 12, and gastroesophageal reflux in seven. In a further 18 patients a diagnosis was established. The cause of chronic cough remained unexplained in six patients. In all 12 patients with eosinophilic bronchitis, the cough improved after treatment with inhaled budesonide 400 micrograms twice daily, and in eight of these patients who had a follow-up sputum analysis, the eosinophil count decreased significantly, from 16.8% to 1.6%. We conclude that eosinophilic bronchitis is a common cause of chronic cough, and that sputum induction is important in the investigation of cough.     

Relationship between bronchial hyperresponsiveness and development of asthma in children with chronic cough

To evaluate the relationship between bronchial hyperresponsiveness (BHR) and the development of asthma in children with chronic cough, we performed methacholine inhalation challenges and transcutaneous oxygen pressure (tcPO2) measurements in 92 children with chronic cough aged from 1-13 years (55 boys and 37 girls; mean, 5.3 years) and followed them for > or = 10 years. Forty-four age-matched children with asthma (24 males and 20 females; mean, 6.5 years) and 44 age-matched children without cough or asthma served as controls (18 males and 26 females; mean, 4.6 years). Consecutive doubling doses of methacholine were inhaled until a 10% decrease in tcPO2 from baseline was observed. The cumulative dose of methacholine at the inflection point of the tcPO2 record (Dmin-PO2) was considered to represent hyperresponsiveness to inhaled methacholine. After 10 years or more of follow-up, 60 of the 92 subjects with cough answered our questionnaire, and 27/60 had been diagnosed with asthma. There was a statistical difference in Dmin-PO2 between the children who presented with chronic cough originally and who developed asthma (asthma-developed group) and those who did not develop asthma (asthma-free group). There was no difference in the value of Dmin-PO2 between the asthma-developed group and the asthma group, or between the asthma-free group and the age-matched control group. Among the children with chronic cough, there was no difference in Dmin-PO2 between girls and boys, either in the asthma-developed group or in the asthma-group. We conclude that 45% of the children with a chronic cough in early life developed asthma, and that BHR in children with chronic cough during the childhood period is a strong risk factor for the development of asthma.     

Exhaled nitric oxide as a noninvasive assessment of chronic cough.

Exhaled nitric oxide (ENO) has been suggested as a marker of airway inflammation. This study aimed to evaluate the role of ENO in the investigation of chronic cough. We measured ENO in 38 adult patients reporting chronic cough, in 23 healthy control subjects, and in 44 asthmatics. In addition to the regular investigation, ENO was measured by a chemiluminescent analyzer using the restricted breath technique. In the chronic cough group, 30 were considered as nonasthmatic, whereas asthma was diagnosed in eight by a positive methacholine challenge. ENO values were significantly higher in patients with chronic cough attributable to asthma as compared with those with chronic cough not attributable to asthma and to healthy volunteers (75.0 ppb; 16.7 ppb; and 28.3 ppb, respectively). The sensitivity and specificity of ENO for detecting asthma, using 30 ppb as the ENO cutoff point, were 75 and 87%, respectively. The positive and negative predictive values were 60 and 93%, and the positive and negative likelihood ratios were 5.8 and 0.3, respectively. We conclude that ENO may have a role in the evaluation of chronic cough. In this group of patients, low ENO suggested little likelihood of asthma. The patients with chronic cough not attributable to asthma showed a low ENO value as compared with healthy volunteers and asthmatics.     

Chronic cough caused by gastroesophageal reflux]

We reported a case of chronic cough due to gastroesophageal reflux (GER). The patient was a 29-year-old woman who had suffered from persistent chronic cough for more than 3 years. She had been treated with high doses of inhaled steroids, oral bronchodilators, and oral corticosteroids on a presumed diagnosis of asthma. However, her cough was not alleviated by these treatments, and the patient was referred to our hospital. She did not exhibit typical GER symptoms except for belch. Although esophagoscopy did not disclose reflux esophagitis, esophageal pH monitoring revealed acid reflux 7 to 8 times higher than the reference value. The patient was treated with a proton-pump inhibitor, which markedly alleviated her cough. Chronic cough due to GER was diagnosed. Although the incidence of chronic cough due to GER was thought to be rare in Japan, the findings in our case report underscored the importance of this association to the differential diagnosis of chronic cough.     

Assessment and measurement of cough: the value of new tools

On systematic investigation, patients with persistent cough are often diagnosed as having asthma, gastro-oesophageal reflux (GOR) and post-nasal drip; often, there is no associated diagnosis. Cough-variant asthma and eosinophilic bronchitis are conditions presenting with cough, usually associated with airway eosinophilia and responding well to corticosteroids. These conditions including asthma are best grouped as 'eosinophil-associated cough'. Analysis of induced sputum for eosinophils is an important tool in the investigation of chronic persistent cough. Reliable ambulatory counters for cough have been developed and the contribution of cough count and intensity to the severity of cough have been partly evaluated, and used in assessing antitussive therapies. Self-scoring evaluations are still widely used, but the inclusion of quality of life tools specifically adapted to the evaluation of cough appears to be a useful tool that can directly measure the impact of chronic cough. We need a greater assessment and evaluation of all these tools.     

Prevalence of asthma symptoms among the adult population in the city of Mashhad (north-east of Iran)

OBJECTIVE: Although there is evidence of worldwide variation in the prevalence of asthma, the prevalence of asthma in adult populations in Iran is not known. METHODS: We studied the prevalence of asthma symptoms among the adult population (aged 20 years and over) in the city of Mashhad using a questionnaire. A total of 5579 subjects, comprising 2835 males and 2744 females, were interviewed by trained medical students. The following were used as asthma symptoms in the questionnaire: recurrent wheeze, recurrent cough or tightness at rest, night cough and wheeze or cough during exercise. Subjects with two symptoms or who had been previously diagnosed with asthma were considered as having asthma. RESULTS: The results showed that 158 subjects (2.8%), comprising 69 males (2.4%) and 89 females (3.2%), had asthma. The proportion of subjects with a family history of asthma (40.5%), a history of allergy (43.7%) and a smoking habit (24.5%) was significantly higher than in normal subjects. Of the subjects determined to have asthma, 120 (76%) had been previously diagnosed as having asthma and were under treatment. However, only 65 subjects (41.1%) were currently under treatment. CONCLUSION: These results suggested a 2.8% prevalence of asthma among the adult population in the city of Mashhad, most of whom had been previously diagnosed and were under treatment.     

Importance of atopic cough, cough variant asthma and sinobronchial syndrome as causes of chronic cough in the Hokuriku area of Japan

OBJECTIVE: A prospective multicentre study was conducted to elucidate the causes of chronic cough in Japan. METHODOLOGY: All consecutive and unselected patients complaining of cough lasting 8 weeks or more, who visited our clinics from 1 June to 31 December 2001, were registered. The causes of chronic cough were diagnosed based on the criteria for definite and probable causes of cough as recommended by the Japanese Cough Research Society. RESULTS: Of the 248 patients enrolled, 72 patients (29.0%) were unavailable for follow up before their diagnostic assessment had been finalized. Among the 176 patients who were adequately assessed, a diagnosis was made in 165 patients (93.7%) either as single cause or as one of two causes: atopic cough in 48 (29.1%) and 11 patients (6.7%); cough variant asthma in 46 (27.9%) and nine patients (5.5%); cough predominant asthma in 14 (8.5%) and three patients (1.8%); and sinobronchial syndrome (SBS) in 28 (17.7%) and 14 patients (8.5%), respectively. A diagnosis of gastro-oesophageal reflux-associated cough was made in a total of four patients (2.4%). CONCLUSION: Atopic cough, asthmatic cough consisting of cough variant asthma and cough predominant asthma, and SBS are major causes of chronic cough in Japan.     

Eosinophilic airway disorders associated with chronic cough

Chronic cough is a major clinical problem. The causes of chronic cough can be categorized into eosinophilic and noneosinophilic disorders, the former being comprised of asthma, cough variant asthma (CVA), atopic cough (AC) and non-asthmatic eosinophilic bronchitis (NAEB).Cough is one of the major symptoms of asthma. Cough in asthma can be classified into three categories; 1) CVA: asthma presenting solely with coughing, 2) cough-predominant asthma: asthma predominantly presenting with coughing but also with dyspnea and/or wheezing, and 3) cough remaining after treatment with inhaled corticosteroid (ICS) and β2-agonists in patients with classical asthma, despite control of other symptoms. There may be two subtypes in the last category; one is cough responsive to anti-mediator drugs such as leukotriene receptor antagonists and histamine H1 receptor antagonists, and the other is cough due to co-morbid conditions such as gastroesophageal reflux.CVA is one of the commonest causes of chronic isolated cough. It shares a number of pathophysiological features with classical asthma with wheezing such as atopy, airway hyperresponsiveness (AHR), eosinophilic airway inflammation and various features of airway remodeling. One third of adult patients may develop wheezing and progress to classical asthma. As established in classical asthma, ICS is considered the first-line treatment, which improves cough and may also reduce the risk of progression to classical asthma.AC proposed by Fujimura et al. presents with bronchodilator-resistant dry cough associated with an atopic constitution. It involves eosinophilic tracheobronchitis and cough hypersensitivity and responds to ICS treatment, while lacking in AHR and variable airflow obstruction. These features are shared by non-asthmatic eosinophilic bronchitis (NAEB). However, atopic cough does not involve bronchoalveolar eosinophilia, has no evidence of airway remodeling, and rarely progresses to classical asthma, unlike CVA and NAEB. Histamine H1 antagonists are effective in atopic cough, but their efficacy in NAEB is unknown. AHR of NAEB may improve with ICS within the normal range. Taken together, NAEB significantly overlaps with atopic cough, but might also include milder cases of CVA with very modest AHR. The similarity and difference of these related entities presenting with chronic cough and characterized by airway eosinophilia will be discussed.     

Clinical diagnosis of current asthma: predictive value of respiratory symptoms in the SAPALDIA study. Swiss Study on Air Pollution and Lung Diseases in Adults.

Bronchial asthma is a very common disease which often remains underdiagnosed. The aim of this study was to determine the predictive value of the most common respiratory symptoms and to explore the best symptom combinations to predict diagnosis of asthma. A questionnaire comprising common respiratory symptoms was submitted to 9,651 subjects aged 18-60 yrs, randomly selected from the Swiss population, of whom 225 subjects (2.3%) had current asthma as confirmed by their general practitioner. Based on these data the authors calculated the predictive values of single symptoms and symptom combinations to diagnose asthma. Wheezing was the most sensitive single symptom (sensitivity 75%). Simple symptoms such as wheezing with dyspnoea, chronic phlegm or chronic cough had specificity greater than 95%. Wheezing with dyspnoea (WD) or nocturnal dyspnoea (ND) had the best positive predictive value (PPV) as isolated symptoms (24% and 21%, respectively). When combining symptoms, wheezing associated with daily dyspnoea at rest or nocturnal dyspnoea showed the best PPV (42% and 39%, respectively), almost double single symptoms such as WD or ND. Wheezing associated with at least two of the three nocturnal symptoms (nocturnal dyspnoea, nocturnal cough or nocturnal chest tightness) had a sensitivity of 80% to diagnose asthma. In conclusion, respiratory symptoms obtained by medical history are reliable predictors of asthma. The findings suggest that particular combinations of symptoms are clinically useful in the differential diagnosis of asthma.     

新疆地区儿童慢性咳嗽病因构成分析

目的分析新疆地区儿童慢性咳嗽的病因特点。方法对收集的653例慢性咳嗽患儿的临床资料进行前瞻性研究,包括主要病因、年龄、民族、过敏原、家族史、环境因素、肺功能情况。结果新疆地区儿童慢性咳嗽病因多为呼吸道感染和感染后咳嗽192例(29.40%)、咳嗽变异性哮喘158例(24.20%)和上气道咳嗽综合征140例(21.44%)。另外,其他病因163例(24.96%),其中双重病因84例(12.87%),病因不明5例(0.77%);慢性咳嗽的主要病因在不同年龄、不同民族亦不同:婴幼儿(0~3岁)慢性咳嗽的主要病因为感染/感染后咳嗽,学龄前儿童(4~6岁)主要病因亦为感染/感染后咳嗽(PIC),学龄期儿童(6~14岁)主要病因为咳嗽变异性哮喘(CVA)和上气道咳嗽综合征(UACS);汉族和哈萨克族儿童慢性咳嗽主要病因以PIC最多,维吾尔族、回族和蒙古族儿童中则以CVA多见。结论新疆地区儿童慢性咳嗽的主要病因依次为呼吸道感染和感染后咳嗽、咳嗽变异性哮喘和上气道咳嗽综合征,不同年龄、不同民族慢性咳嗽的病因构成比不同。具有个人过敏史、家族过敏史、不良外界环境接触史及肺功能异常的患儿更易诊断为咳嗽变异性哮喘。