Diagnosis and management of asthma in preschoolers: A Canadian Thoracic Society and Canadian Paediatric Society position paper

Asthma often starts before six years of age. However, there remains uncertainty as to when and how a preschool-age child with symptoms suggestive of asthma can be diagnosed with this condition. This delays treatment and contributes to both short- and long-term morbidity. Members of the Canadian Thoracic Society Asthma Clinical Assembly partnered with the Canadian Paediatric Society to develop a joint working group with the mandate to develop a position paper on the diagnosis and management of asthma in preschoolers.In the absence of lung function tests, the diagnosis of asthma should be considered in children one to five years of age with frequent (≥8 days/month) asthma-like symptoms or recurrent (≥2) exacerbations (episodes with asthma-like signs). The diagnosis requires the objective document of signs or convincing parent-reported symptoms of airflow obstruction (improvement in these signs or symptoms with asthma therapy), and no clinical suspicion of an alternative diagnosis. The characteristic feature of airflow obstruction is wheezing, commonly accompanied by difficulty breathing and cough. Reversibility with asthma medications is defined as direct observation of improvement with short-acting ß₂-agonists (SABA) (with or without oral corticosteroids) by a trained health care practitioner during an acute exacerbation (preferred method). However, in children with no wheezing (or other signs of airflow obstruction) on presentation, reversibility may be determined by convincing parental report of a symptomatic response to a three-month therapeutic trial of a medium dose of inhaled corticosteroids with as-needed SABA (alternative method), or as-needed SABA alone (weaker alternative method). The authors provide key messages regarding in whom to consider the diagnosis, terms to be abandoned, when to refer to an asthma specialist and the initial management strategy. Finally, dissemination plans and priority areas for research are identified.     

Treatment of acute asthma

Asthma is a chronic inflammatory disorder of the airways with an increasing prevalence over the last 20 years worldwide. Exacerbation of asthma is defined as rapidly progressive increase in shortness of breath, cough, wheezing, or chest tightness, or some combination of these symptoms and a decrease in expiratory airflow that can be qualified by measurement of pulmonary function such as the peak expiratory flow rate (PEFR) and FEV1. All patients with asthma are at risk of having exacerbations and it has been described previously as acute asthma, asthma or status asthmaticus. A number of medical condition such as chronic obstructive pulmonary disease (COPD), congestive heart failure, upper airway obstruction, hyperventilation syndrome, or vocal cord dysfunction may mimic the diagnosis of asthma attack, however it can be differentiated by history, physical examination, and some laboratory tests. It is a common medical emergency. The severity of exacerbations may range from mild to life threatening and immediate optimal management is of importance to prevent mortality. Morbidity and mortality are mostly related with inadequate emergency treatment and delay in referring to hospital. This review mainly focuses on the treatment of acute asthma considering the recommendations of GINA guideline.     

Bronchoprovocation testing

Bronchial hyperresponsiveness is a constant feature of asthma even when airflow obstruction is absent. Detecting nonspecific bronchial hyperresponsiveness is useful when the diagnosis of asthma has not been confirmed or when a patient describes symptoms of cough, chest tightness, and dyspnea that cannot be ascribed to other causes. Also, because wheezing is a symptom of other disorders, inhalation challenge tests can be useful in defining its cause when reversible airflow obstruction has not been documented. A number of easy and safe techniques are available to detect nonspecific bronchial hyperresponsiveness. The histamine and methacholine challenge have had the most widespread use in the clinical pulmonary function laboratory. The exercise and cold air challenges are limited by expense. The osmotic challenge may gain more acceptance as experience with this technique grows. These different agents have the advantage of simplicity, reproducibility, a low number of adverse effects, and a high degree of specificity and sensitivity. A limited number of asthmatics show bronchial hyperresponsiveness to specific agents such as chemical sensitizers in the workplace, aeroallergens, aspirin, nonsteroidal anti-inflammatory agents, and sulfiting agents. Bronchoprovocation testing with these agents is usually reserved for the hospital laboratory because severe or delayed reactions may occur. These tests, however, can be extremely useful in defining a population of sensitive asthmatics.     

Prevalence of asthma and respiratory symptoms by age, gender and smoking behaviour in Samsun, North Anatolia Turkey

Asthma is a major health problem worldwide. This is the first study determining the prevalence of asthma among adults in Samsun which is situated in the centre of the Black Sea region of Turkey. The aim of our study was to assess the prevalence of asthma and asthmatic symptoms, and the relationships of these with age, gender and smoking behaviour in this region. A questionnaire interview adapted from the European Respiratory Community Health Survey (ERCHS) was performed by health centre officers with selected people between November-December, 2002. The study population included a total of 1.916 [810 men (42.3%) and 1.106 women (57.7%)] inhabitants of Samsun city center, aged 15 years of age or above. The mean age was 37.8 years+/-15.5, the prevalence of asthma was 2.7%, receiving asthma medicine was 2.2%, the prevalence of wheezing in the last 12 months was 15.5% and shortness of breath with wheezing was 11.6%. The frequency of symptoms was higher among the elderly population when compared to other groups (p<0.0001). Asthma diagnosis by a physician was more frequent among women (chi2=5.16, p<0.05). Morning cough, day time cough, chronic cough, phlegmy cough and waking up with cough symptoms were more frequent among the smokers (p<0.001). Asthma diagnosis and asthma treatment are at a very low level compared to reported asthma related symptoms.     

Normal airway responsiveness to methacholine in cardiac asthma

Cardiac asthma has been used as a synonym for episodes of cough, dyspnea, and wheezing caused by left ventricular dysfunction. The similarity of the terms bronchial asthma and cardiac asthma, and the observed symptoms of each disease implies a common pathophysiology. Bronchial asthma is characterized pathologically by airway narrowing, inflammation, edema, and obstruction by mucus. Bronchial asthma is defined as increased responsiveness of the tracheobronchial tree, which is manifested clinically as reversible expiratory airflow obstruction. The classic symptoms of bronchial asthma are cough, dyspnea, and wheezing. Cardiac asthma produces the same symptoms, but the pathophysiology producing these symptoms is not well described. We describe two patients with cardiac asthma who failed to demonstrate airway hyperresponsiveness to nonspecific bronchoprovocation testing and we postulate that these patients' symptoms were produced exclusively by left ventricular failure.     

Omalizumab in the Treatment of Allergic Respiratory Disease

In children and young adults, asthma often presents many of the following features: atopy is common; airflow obstruction is fully reversible; differential diagnoses are few (except in the very young); and concomitant illnesses are uncommon. Although asthma in the elderly (meaning, for the purposes of this discussion, age 65 years and older) may share all of these characteristics, exceptions become increasingly common with advancing age. In older persons, the prevalence of allergic asthma (as defined by skin test sensitivity) is relatively small; fixed airflow obstruction may be present during clinical remissions of asthma; the differential diagnosis of new-onset wheezing is broad; and comorbid disease, especially coronary artery disease, often complicates both diagnosis and therapy. Even the definition of asthma becomes somewhat obscured in an older population: persons with chronic bronchitis and emphysema who exhibit episodic dyspnea and wheezing and a reversible component to their airflow obstruction challenge our nosology. One must attempt to decide whether their asthmaticlike condition, often referred to as “asthmatic bronchitis,” is the same illness that we call asthma. Thus, although in some instances asthma in the elderly is simply a continuation of this chronic condition into old age, in others it raises a host of special diagnostic and therapeutic considerations.     

Asthma in the Elderly

In children and young adults, asthma often presents many of the following features: atopy is common; airflow obstruction is fully reversible; differential diagnoses are few (except in the very young); and concomitant illnesses are uncommon. Although asthma in the elderly (meaning, for the purposes of this discussion, age 65 years and older) may share all of these characteristics, exceptions become increasingly common with advancing age. In older persons, the prevalence of allergic asthma (as defined by skin test sensitivity) is relatively small; fixed airflow obstruction may be present during clinical remissions of asthma; the differential diagnosis of new-onset wheezing is broad; and comorbid disease, especially coronary artery disease, often complicates both diagnosis and therapy. Even the definition of asthma becomes somewhat obscured in an older population: persons with chronic bronchitis and emphysema who exhibit episodic dyspnea and wheezing and a reversible component to their airflow obstruction challenge our nosology. One must attempt to decide whether their asthmaticlike condition, often referred to as “asthmatic bronchitis,” is the same illness that we call asthma. Thus, although in some instances asthma in the elderly is simply a continuation of this chronic condition into old age, in others it raises a host of special diagnostic and therapeutic considerations.     

Aging and disability affect misdiagnosis of COPD in elderly asthmatics: the SARA study

STUDY OBJECTIVES: This study investigated to what extent a diagnosis of COPD is erroneously made or the disease remains unrecognized in elderly asthmatic patients, and identified factors leading to misdiagnosis and underdiagnosis of asthma in such patients. DESIGN: A multicenter study involving 24 Italian pulmonary or geriatric institutions. PATIENTS: One hundred twenty-eight asthmatic patients (98 women, 76.6%) aged 73 +/- 6.4 years (mean +/- SD) were selected from the cohort of the Salute Respiratoria nell'Anziano (respiratory health in the elderly) study. METHODS: All patients underwent a clinical evaluation that included clinical history and spirometry with a bronchodilator test. A diagnosis of asthma was based on criteria proposed by international guidelines adapted to the elderly population. A multidimensional geriatric assessment was performed to estimate physical and cognitive impairments and mood state. Finally, the diagnosis of respiratory disease previously made by a doctor, if any, was recorded. RESULTS: Of asthmatic patients, COPD had been improperly diagnosed in 19.5%, whereas 27.3% of asthmatic patients did not report any previous diagnosis of asthma. The main correlates of misdiagnosis were older age and disability. Conversely, underdiagnosis was associated with better functional conditions, expressed by spirometry, even when wheezing or a significant response to the bronchodilator test occurred. CONCLUSIONS: Asthma in the elderly is frequently confused with COPD. Misdiagnosis can be related to older age and to greater degree of disability. Asthma in patients with mild functional impairment may be underdiagnosed in spite of overt respiratory symptoms suggestive of asthma.     

Asthma in the elderly

A population aged 65 and over has been increasing in the developed countries. The prevalence of asthma in elderly patients is estimated between 6.5 and 17%. Asthma is an important cause of morbidity and mortality in the elderly. Moreover, death due to asthma occurs mostly in elderly patients. Only a few studies have reported the characteristics of asthma in the elderly patients. Two distinct clinical presentations of asthma have been described in the elderly. There are differences both in the pathophysiology and the clinical manifestation of asthma between elderly patients with a long-standing disease and those with late-onset disease. Additionally, aging of the respiratory system influences the asthma presentation. Asthma has been presented for many years may lead to persistent obstructive ventilatory defect and can mimic chronic obstructive pulmonary disease. Irreversible obstruction is commonly observed in elderly patients with asthma. The differential diagnosis of asthma is difficult in older adults and asthma is underrecognized and undertreated in the older population. Undertreatment is common in elderly asthmatics which largely is related to diagnostic issues.     

The prevalence of reversible airflow obstruction and/or methacholine hyperreactivity in random adult asthma patients identified by administrative data.

BACKGROUND: Asthma is a chronic inflammatory lung disease. It is commonly diagnosed and treated on the basis of clinical impression, although national guidelines recommend documenting reversible airflow obstruction. OBJECTIVES: Determine the frequency of reversible airflow obstruction, and/or methacholine hyperreactivity during 2003 in a well-characterized population with a low-risk asthma diagnosis during 2001. METHODS: Of a total population of 7460 low-risk adult (18-64 years) asthma patients (no hospitalizations or emergency department visits; < 3 oral steroid courses; < 12 beta-agonist canisters; and < 3 prescibers, all in prior 12 months) cared for by a large health care program, a random sample of 400 was recruited to undergo a diagnostic asthma evaluation. The evaluation included a physical examination, medical record review, questionnaires, allergy testing, spirometry for airflow obstruction and reversibility, and/or methacholine hyperreactivity. RESULTS: Of the 400 randomly selected patients, 106 (26.5%) started and 82 (77.3%) completed the asthma evaluation. Evaluated subjects were predominately female (71%), middle-aged (mean 51.0 +/- 11.0 years), diagnosed asthmatics for long duration (mean 22.1 +/- 17.5 years), and nonsmokers (88.7%). Asthma was confirmed in 62.1% (51 of 82) based on a deltaFEV1 12% or greater after albuterol (n = 38), deltaFEV1 15% or greater after Advair (n = 6), or a positive methacholine challenge (n = 7). Only 35 of 400 patients (8.7%) ever had reversibility measured in their medical record. Of these, only 12 (34.3%) had a deltaFEV1 12% or greater after albuterol. Reversibility was confirmed in all six who had asthma evaluations. CONCLUSIONS: More than one third of low-risk adult asthmatics cannot be confirmed to have asthma 2 years later. Spirometry that documented reversibility in the medical record accurately predicted asthma confirmation. Physicians should more widely perform spirometry with reversibility to establish the diagnosis of asthma as recommended by national asthma guidelines.     

Eosinophilic airway disorders

Diseases of the airway are common and make up a significant proportion of the respiratory physician's workload. The major contributors to this situation, such as asthma, chronic obstructive pulmonary disease (COPD), and chronic cough, all result from airway inflammation and often have an overlapping clinical picture, which in some instances makes accurate clinical diagnosis difficult. Asthma is a condition characterized by variable airflow obstruction, airway hyper-responsiveness, and airway inflammation, which is usually eosinophilic. However, the relationship between eosinophilic inflammation and asthma is complex, with only a weak correlation between the severity of airway inflammation and the markers of the severity of asthma, such as Pc20 and FEV1. Eosinophilic bronchitis is characterized by a chronic cough and sputum eosinophilia without airway hyper-responsiveness or variable airflow obstruction. The asthma phenotype is characterized by microlocalization of mast cells in the airway smooth muscle, emphasizing the importance of airway smooth muscle dysfunction in asthma. COPD has generally been considered to be a neutrophilic disease, in contrast to asthma. However, there is increasing evidence that a significant subgroup exists consisting of patients with stable COPD who have chronic airway eosinophilia with a more steroid-responsive disease. This article covers the role of eosinophils in the airway disorders asthma, COPD, and eosinophilic bronchitis.     

Effect of Obesity on Asthma Phenotype is Dependent upon Asthma Severity

Background. We recently reported that obese and non-obese patients with asthma have similar airflow limitation and bronchodilator responsiveness, but obese patients have more symptoms overall. There is limited information on the effect of obesity on asthmatics of varying severity measured by objective physiological parameters. Understanding how obesity affects asthmatics of differing severity can provide insights into the pathogenesis of asthma in the obese and a rationale for the therapeutic approach to such patients. Methods. Participants with asthma from two American Lung Association—Asthma Clinical Research Center (ALA-ACRC) studies were grouped by tertiles of airflow obstruction (forced expiratory volume in one second (FEV₁%) predicted, FEV₁/forced vital capacity (FVC)) and methacholine reactivity (PC₂₀FEV₁). Within each tertile, we examined the independent effect of body mass index (BMI), divided into normal weight, overweight, and obese categories, on lung function, airway reactivity, and symptoms. Results. Overall, both FEV₁ and FVC decreased and symptoms worsened with increasing BMI; airway reactivity was unchanged. When stratified by the degree of airflow obstruction, higher BMI was not associated with greater airway reactivity to methacholine. Higher BMI was associated with more asthma symptoms only in the least obstructed FEV₁/FVC tertile. When stratified by degree of airway reactivity, BMI was inversely associated with FVC in all PC₂₀FEV₁ tertiles. BMI was directly associated with asthma symptoms only in those with the least airway reactivity. Conclusions. Obesity does not influence airway reactivity in patients with asthma and it is associated with more symptoms only in those with less severe disease.     

Chronic cough and phlegm in young adults.

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines underline that the presence of chronic cough and sputum production before airflow obstruction offers a unique opportunity to identify subjects at risk of chronic obstructive pulmonary disease for an early intervention. Current epidemiological data on these subjects are scant. Between 1998-2000, the authors evaluated the prevalence and characteristics of these symptoms by a multicentre cross-sectional survey of Italian people aged between 20-44 yrs from the general population (Italian Study on Asthma in Young Adults (ISAYA)). Besides the questions on asthma, more than 18,000 subjects answered the question: "Have you had cough and phlegm on most days for as much as 3 months per year and for at least two successive years?" The adjusted prevalence of subjects with chronic cough and phlegm was 11.9%, being 11.8% in males and 12.0% in females. From these subjects approximately 20% reported coexisting asthma and approximately 30%, predominately females, were nonsmokers. The survey showed that sex (female), smoking and low socioeconomic status were significantly and independently associated with chronic cough and phlegm, current smoking playing the major role. The prevalence of subjects with chronic cough and phlegm is startlingly high among young adults. Further follow-up studies are needed to establish how many of them will go on to develop chronic obstructive pulmonary disease.     

Asthma or not? The value of flow volume loops in evaluating airflow obstruction.

Large airway obstruction can present with symptoms typically associated with asthma, including cough, dyspnea, or wheezing. Obstruction of the large airways should be considered in the differential diagnosis of patients with difficult to manage asthma, particularly those with known risk factors for tracheal disease, atypical clinical features, or lack of response to standard asthma therapy. Spirometry and flow volume loops are valuable diagnostic tools in this evaluation. This article discusses two cases in which large airway obstruction mimicked asthma and reviews the characteristic flow volume loop patterns associated with large airway lesions.     

Features of Asthma in Older Adults

A study compared clinical and functional features of elderly patients with asthma to younger patients at a university medical center. Older patients had a larger than predicted reduction in pulmonary function parameters even though physician-assessed severity, duration of diagnosed asthma, and smoking status were no different between groups. A significant increase in the comorbid diagnosis of chronic obstructive pulmonary disease was noted in older patients with asthma. These two points support the hypothesis that long-standing asthma may lead to irreversible airflow obstruction. Older patients reported better medication compliance and decreases in some respiratory symptoms and demonstrated lower health care utilization.     

Relationship between lung function and asthma symptoms in patients with difficult to control asthma.

Several studies have demonstrated a poor relationship between measures of asthma control and lung function in patients with asthma. We sought to examine this relationship in a cohort of difficult to control asthmatics attending a hospital outpatient clinic. FEV1 % and asthma control scores (ACSs) were measured at the first clinic visit and at a follow-up visit. A total of 59 patients took part in the study. At the initial visit, FEV1 % correlated with limitation of activity (p = 0.002), shortness of breath (p = 0.02), wheezing (p = 0.029), and ACS (p = 0.014). However, at follow-up, there was no correlation between FEV1 % and any measured index of asthma control. When patients with severe fixed airflow obstruction were excluded from the analysis (n = 16), FEV1 % at follow-up became significantly correlated with night waking (p = 0.02), wheezing (p = 0.05), and ACS (p = 0.036). The improvement in asthma control score at follow-up was significantly and strongly associated (r = 0.51 for total asthma control, p < 0.001) with the improvement in lung function in patients without severe fixed airflow obstruction. Lung function was not associated with any measure of asthma control in patients with severe fixed airflow obstruction. FEV1 % correlates well with asthma symptoms in difficult asthma patients with poor control but not when control improves. This loss of relationship is due to subjects with severe fixed airflow obstruction where good subjective control does not exclude the presence of significant obstruction. How severe fixed airflow obstruction should be prevented, delayed, or managed in asthma requires further research.     

Contents of chemical mediators in sputum in a case of mycoplasma pneumoniae bronchiolitis resembling bronchial asthma]

A case of Mycoplasma pneumoniae bronchiolitis with hypoxemia is presented. A 41-year-old man was admitted to hospital because of fever, productive cough and dyspnea with wheezing of one month duration. On admission, bronchial asthma was suspected on the basis of reversible airflow obstruction and sputum eosinophilia. However, despite treatment with bronchodilators, his condition did not improve. Chest film and computed tomogram revealed small nodular shadows and tramlines in the bilateral lower lung fields, and pulmonary function tests indicated peripheral airway obstruction. Serologic titer for Mycoplasma pneumoniae was 1:160. A diagnosis of bronchiolitis due to Mycoplasma pneumoniae was made. Improvement of lung function and roentgenographic findings was observed following administration of erythromycin and doxycycline. The concentrations of prostanoids in sputum were markedly higher than in cases of bronchial asthma, and decreased as he improved. These observations suggest that Mycoplasma bronchiolitis should be considered in the differential diagnosis of wheezing, and that measurement of prostanoids in sputum may be useful in the differentiation of infective bronchiolitis and bronchial asthma.     

Performance of the ISAAC Questionnaire to Establish the Prevalence of Asthma in Adolescents: A Population-Based Study

Background. The epidemiology of asthma has been investigated with questionnaires, such as the International Study of Asthma and Allergies in Childhood protocol. Aim. To investigate the performance of the questions of the International Study of Asthma and Allergies in Childhood questionnaire to diagnose asthma in adolescents. Methods. This is a population-based cross-sectional study of adolescents in the Syndrome of Obesity and Risk Factors for Cardiovascular Disease study. The validity of the asthma symptoms of the International Study of Asthma and Allergies in Childhood protocol was assessed by calculating sensitivity, specificity, positive and negative posttest probabilities, and Youden's Index, taking as a gold standard the history of a medical diagnosis of asthma. Risk ratios (RRs) and 95% confidence intervals (CIs), adjusting for sex and age, were calculated using Cox regression model. Results. In total, 575 adolescents were investigated. Overall, 28.7% reported a lifetime medical diagnosis of asthma, and 40.0% reported at least one episode of wheezing. Ever wheezing had the highest sensitivity (80.6%) for the diagnosis of asthma, compared with the other ISAAC questions. Adolescents who reported ever wheezing were about 8 times more likely (adjusted RR: 8.3; 95% CI: 4.9–14.2) to have ever had asthma, independent of age and sex. Symptoms within the last 12 months (wheezing, cough without cold or respiratory infection, sleep disturbed due to wheezing, wheezing due to exercise, speech limited due to wheezing) had specificity of 92.0% or higher. Dry cough at night without cold or respiratory infection was the strongest independent predictor of asthma (adjusted RR: 8.8; 95% CI: 6.1–12.7). Conclusions. Ever wheezing is the most sensitive indicator of the diagnosis of asthma but falsely identifies a portion of adolescents as asthmatic. Symptoms of asthma in the last 12 months, such as cough without cold or respiratory infection, are rarely positive in the absence of a lifetime asthma diagnosis. The combination of ever wheezing for screening and the presence of other symptoms within the past 12 months to confirm the diagnosis could be an effective strategy to identify the prevalence of asthma in communities.     

Relationship of wheezing to airflow obstruction in asthmatic children and a history of cough-variant asthma.

The aim of this study was to examine the relationship of wheezing to airflow obstruction during acute episodes of asthma in patients who had CVA (Cough variant asthma). Two groups of asthmatic children, one group with a past history of CVA (n = 13) and the other group without such a history (n = 14), were followed longitudinally for 12 months. During that time, they were evaluated for the presence of wheezing and the severity of airflow obstruction during acute episodes of asthma. Significant airflow obstruction occurred free of wheezing more frequently and the presence of clinical wheezing was associated with more severe airflow limitation, in asthmatic patients with a past history of CVA than in those without such a history. We conclude that asthmatic patients who have experienced CVA develop the wheezing symptom at a higher level of airflow obstruction.     

Besonderheiten des kindlichen Asthmas

Asthma is the most commonly observed chronic disease in childhood and the incidence has been increasing in industrialized countries over the last decades. Airway obstruction due to increased sensitivity of the small airways, mucus production and chronic inflammation are key features in the pathophysiology of asthma. Environmental and genetic factors predispose for the disease, which is clinically characterized by sudden occurrence of episodes of expiratory airway obstruction (wheezing). In the majority of preschool infants such obstructive episodes are triggered by viral infections (especially during the winter season) and do not necessarily predispose for asthma later in adulthood. Patient and family history (e.g. atopy), good clinical examination and differential diagnosis (e.g. exclusion of cystic fibrosis) are of prime importance as the role of lung function measurements is limited as the disease frequently occurs before the age of 5 years. Information about asthma is important for children, parents and caregivers. Acute and chronic medication should control asthma symptoms and allow the affected child to lead a normal life including physical exercise.