Bronchiectasis in children: Clinical manifestations and evaluation

INTRODUCTION — Worldwide, the prevalence of bronchiectasis unrelated to cystic fibrosis exceeds that of cystic fibrosis-associated bronchiectasis. Although bronchiectasis remains a major contributor to chronic respiratory morbidity in both affluent [1,2] and less affluent countries [3,4], it remains an underrecognized and neglected disease.

Bronchiectasis was previously considered to be irreversible and progressive. However, studies have shown that disease progression in children can be halted and even reversed (as measured by imaging) with optimized clinical management [5]. Thus, awareness of disease leading to early recognition, evaluation, and prompt treatment is particularly important in children to reduce disease progression and the associated health and economic consequences [6,7].

The clinical presentation and evaluation of a child with bronchiectasis due to causes other than cystic fibrosis is discussed below. The causes and treatment of bronchiectasis in children without cystic fibrosis are discussed separately. (See "Bronchiectasis in children: Pathophysiology and causes" and "Bronchiectasis in children without cystic fibrosis: Management".)

DEFINITION — Bronchiectasis in children is defined as the presence of abnormal bronchial dilatation on chest computed tomography (CT) scans, in combination with a clinical syndrome of recurrent or persistent wet/productive cough, airway infection, and/or inflammation [5,8].

EPIDEMIOLOGY — There are few reliable prevalence estimates for bronchiectasis in children. Extrapolation of published data suggests highly variable incidence, ranging from 0.2 to 735 per 100,000 children annually [9]. The prevalence is particularly high among children in indigenous populations in Australia, New Zealand, and Alaska (1 in every 63 to 68 children [10]) and low-income settings [11]. The disease is increasingly recognized in the general population, especially in major cities.

The underlying cause of the bronchiectasis also varies substantially among populations. As examples, infectious causes are more common in certain low-resource or indigenous populations, while immunodeficiencies and other genetic causes are more common in populations with consanguinity or founder mutations. (See "Bronchiectasis in children: Pathophysiology and causes".)

CLINICAL MANIFESTATIONS — Children and youth with bronchiectasis can present with a wide variety of symptoms and signs (table 1) because it is the end result of a variety of illnesses ranging from congenital causes to postinfectious and primary immunodeficiencies. The clinical manifestations depend primarily on disease severity and whether an underlying disease is present. For example, children with underlying disease risk factors (eg, primary immunodeficiency) or previous protracted bacterial bronchitis (PBB) may present with relatively mild symptoms during routine clinical surveillance. By contrast, children with limited access to medical care or with severe underlying disease may present with more severe symptoms including hemoptysis [9,12].

Respiratory symptoms and signs — Bronchiectasis is associated with a variety of nonspecific symptoms and signs [13]. These are more likely present in those with more severe bronchiectasis (defined radiographically) [14].

Respiratory symptoms of bronchiectasis include:

●Chronic wet/productive cough – Chronic cough that sounds wet and/or is productive of mucus or phlegm is the most common symptom of bronchiectasis. The cough is typically chronic but may be intermittent post-treatment (unlike that in adults, in which the bronchiectasis-related cough typically persists) [15]. The character and frequency/intensity of the cough reflect its severity (more likely continuously present if bronchiectasis is severe) and state (stable state versus exacerbation) [16]. When productive cough is present, the sputum is usually purulent (prior to treatment) but may be nonpurulent, particularly in children with primary ciliary dyskinesia when in a stable state (ie, not in an exacerbation).

If antibiotics are used in the initial treatment of chronic wet cough, failure of the wet/productive cough to respond to four weeks of antibiotics predicts presence of bronchiectasis (adjusted odds ratio 20.9, 95% CI 5.4-81.8) [17].

●Recurrent infections – Recurrent pneumonia is both a risk factor [8,18] and presenting symptom [19] of childhood bronchiectasis. In some cases, bronchiectasis may be first identified after a single severe episode of pneumonia, particularly after particular infections such as adenovirus and mycoplasma.

Children may also present with recurrent episodes (>3 per year) of PBB [20,21]. The adjusted odds ratio of having bronchiectasis in those with recurrent PBB is 11.5 (95% CI 2.3-56) [20]. This risk is also higher in at-risk populations such as young indigenous children living in high-income countries. In a study of infants from an indigenous Australian population who were hospitalized for bronchiolitis, 20 percent developed bronchiectasis within 13 months after discharge. The presence of chronic cough at three to four weeks post-hospitalisation was a risk factor for a subsequent diagnosis of bronchiectasis (odds ratio 3, 95% CI 1.1-7) [22].

●Dyspnea – Children with bronchiectasis may have dyspnea, especially on exertion. Although dyspnea is generally rare in cohorts of children in which bronchiectasis was diagnosed early [13,23], it is reported in up to 81 percent of children with bronchiectasis in low- or middle-income countries (table 1). Dyspnea may reflect the airway hyperresponsiveness that is common in children with severe bronchiectasis [24].

●Hemoptysis – Hemoptysis is present in 1 to 10 percent of patients and generally reflects more severe bronchiectasis [15]. It may be a presenting symptom, particularly in low- or middle-income countries and if diagnosis is delayed but occasionally in high-income countries [19]. Hemoptysis can be life-threatening; a study from the United States involving 300 children admitted to intensive care with hemoptysis reported that bronchiectasis was the cause in 10 percent and was an independent risk factor for in-hospital mortality [25]. However, 85 percent of the patients with bronchiectasis in this study had cystic fibrosis, so these findings may not reflect the prognosis of patients with other causes of bronchiectasis [25].

●Other – Other respiratory symptoms that are features of an underlying disease may be found. These include symptoms/signs associated with tracheomalacia (monophonic wheeze, stridor, brassy cough, pectus excavatum) and laryngeal dysfunction or cleft (hoarse voice, stridor).

On physical examination, signs associated with bronchiectasis include (table 1):

●Chest crackles – Common; reported in up to 89 percent of children in some cohorts [26]. Like other signs and symptoms, the presence of crackles varies with the patient's state (initial diagnosis, stable state post-treatment or exacerbation).

●Chest rhonchi or wheeze – Wheeze (which reflects airway obstruction) is sometimes present (10 to 66 percent of cohorts). The presence of wheeze also varies with the patient's state (ie, initial diagnosis, stable state post-treatment, or exacerbation).

●Chest deformity (hyperinflation, Harrison sulci, pectus carinatum) – Present in 15 to 29 percent of children.

●Digital clubbing – Present in 4 to 73 percent of children.

Systemic symptoms and signs — Systemic markers of bronchiectasis vary widely, reflecting the associated comorbidities and complications as well as the underlying etiology of the child's bronchiectasis.

Children with bronchiectasis may have growth failure and other comorbidities that may not directly relate to markers of bronchiectasis severity. These include cardiac dysfunction, pulmonary hypertension, sleep disorders, gastroesophageal reflux, psychosocial challenges, and impaired quality of life [15,27,28]. Comorbidities may also be caused by the medications used for treating the child's bronchiectasis, such as corticosteroids.

Other symptoms and signs are related to the underlying cause or risk factor associated with the bronchiectasis (table 2). Examples include:

●Features of extreme prematurity [10]

●Congenital anomalies associated with swallowing dysfunction, such as previous esophageal atresia/tracheoesophageal fistula [29]

●Sinusitis with or without situs inversus in those with primary ciliary dyskinesia

●Syndromic features (eg, trisomy 21, in which bronchiectasis is related to dysphagia associated with recurrent small-volume aspiration)

●Primary immunodeficiency, in which symptoms/signs may be specific (eg, ataxia-telangiectasia) or nonspecific (eg, scarred tympanic membrane from previous chronic suppurative otitis media)

Some of the comorbidities that are seen in adults with bronchiectasis, such as rheumatic disease and amyloidosis [7], are much rarer in children. (See "Clinical manifestations and diagnosis of bronchiectasis in adults", section on 'Etiologies'.)

OVERVIEW AND GOALS OF THE EVALUATION — For a child with suspected bronchiectasis, goals of the evaluation are:

●Confirm or exclude the diagnosis of bronchiectasis

●Determine its severity and complications

●Assess for an underlying cause or risk factor for the bronchiectasis, which informs treatment decisions

●General assessments to optimize management of the child's bronchiectasis, including bronchiectasis-related education and counselling to enhance adherence to treatment

This information informs the evaluation plan, which includes a panel of tests in all children and more in-depth investigations in selected patients to determine the cause of the bronchiectasis (table 2). Defining the cause of the bronchiectasis and/or other factors that may contribute (so-called "treatable traits") also informs the management strategy [5]. (See 'Further evaluation' below and "Bronchiectasis in children without cystic fibrosis: Management".)

INITIAL EVALUATION OF SUSPECTED BRONCHIECTASIS

Medical history

●History of present illness – The initial evaluation of a child suspected of having bronchiectasis includes a targeted history focusing on current and past symptoms (table 1). Key information includes the characteristics of cough, including its onset and duration, type of cough (wet or dry, time of day), history of response to therapies (if any), and purulence (if sputum can be expectorated).

If the cough is wet-sounding, symptoms suggesting one of the more common and treatable causes of bronchiectasis should be specifically explored:

•Protracted bacterial bronchitis (PBB) – Recurrent PBB is a relatively common cause of bronchiectasis, especially in certain indigenous populations in Australia, New Zealand, and Alaska and some other populations with limited access to health care [10]. Symptoms of PBB include chronic (>4 weeks) wet or productive cough. Untreated or recurrent PBB can progress to bronchiectasis, which should be suspected in children who have not responded to four weeks of antibiotics or who have >3 episodes per year (figure 1). (See "Causes of chronic cough in children", section on 'Protracted bacterial bronchitis'.)

•Foreign body aspiration – The possibility of foreign body aspiration should be suspected in a child with a history of wheeze, hemoptysis, and sudden onset of cough/choking. (See "Causes of chronic cough in children", section on 'Inhaled retained airway foreign body'.)

●Related medical history – The past medical history should be explored for possible causes or contributing factors, including:

•Neonatal history, including prematurity or neonatal distress requiring oxygen (suggests primary ciliary dyskinesia)

•Previous severe pneumonia or recurrent pneumonias

•History or risk factors for tuberculosis

•HIV status

•Cardiothoracic surgery

•Symptoms or risk factors for dysphagia (eg, neurologic dysfunction)

•Features of primary immunodeficiency disease (eg, recurrent infections) as well as risk factors such as consanguinity and family history (see "Approach to the child with recurrent infections")

•Specific questioning on possible inhalation/recurrent small-volume aspiration injuries (eg, lipoid substances [30]) should also be sought in some cultural settings [31]

●Other history

•Psychosocial history – Understanding the family's resources and cultural setting informs management strategies. This includes health literacy, which informs the type of education resources used, and/or use of culture-specific educational tools for indigenous people.

•Exposure to tobacco smoke and other environmental pollutants – These exposures can contribute to bronchiectasis and should be addressed as part of a treatment plan.

•Activity level – The child's activity level should also be assessed for presence of exertional dyspnea. In addition, activity level is relevant to general health as children with bronchiectasis often have suboptimal physical activity levels [32].

Physical examination — The physical examination includes:

●Respiratory signs – The most common sign consistent with bronchiectasis is chronic wet cough, sometimes with wheezing. Patients with more advanced disease may have digital clubbing or chest wall deformity, such as hyperinflation, pectus carinatum, or Harrison sulci (transverse depressions along the sixth and seventh costal cartilages at the site of attachment of the anterior part of the diaphragm) (table 1). Identification of scars from previous cardiothoracic surgery may supplement the past medical history.

●General examination – This includes assessment of growth and assessment of other systems (eg, cardiac, skin) with particular attention to issues raised by the medical history. As an example, a child with dysphagia should have a thorough neurologic assessment.

Imaging

●Chest radiograph – A chest radiograph should be performed in all children with chronic wet cough [33]. The primary purpose is to evaluate for clues to the respiratory symptoms, such as foreign body aspiration or pneumonia, which sometimes lead to bronchiectasis. The chest radiograph should not be used to exclude bronchiectasis, as it is insensitive for detecting bronchiectasis [34]. As an example, in a series of 14 patients with bronchiectasis diagnosed by high-resolution computed tomography (HRCT), none had evidence of bronchiectasis on chest radiograph [35].

When the bronchiectasis is moderate to severe, it may be possible to detect a "tram track" appearance, which consists of parallel lines that reflect the thickened walls of dilated bronchi (image 1). Additionally, if the bronchiectasis is severe, the dilated airway structures may appear as ring-like structures (if the dilated lumen filled with air) or cystic opacities (if the lumen is filled with mucus).

●Advanced imaging – Advanced imaging (typically multidetector CT [MDCT] with HRCT) should be performed in children with chronic wet cough who have an increased likelihood of underlying bronchiectasis, such as those with a poor response to appropriate antibiotics [17], recurrent PBB [20], or underlying immunodeficiency. HRCT is not indicated for children with first presentation of chronic wet cough and no other signs or risk factors for bronchiectasis.

•HRCT – HRCT is moderately sensitive and specific for diagnosing the condition. HRCT usually consists of 1 mm sections of the lung every 10 to 15 mm intervals with a high spatial resolution algorithm [36].

Features of bronchiectasis on HRCT are:

-Increased bronchoarterial ratio (BAR) – The pathognomonic feature of bronchiectasis seen on HRCT is an abnormally dilated airway compared with the adjacent artery. The BAR is used as an index for this dilatation; it is defined as the ratio of the inner diameter of an airway to the outer diameter of adjacent artery that is within 5 mm in a nontangential plane (image 2). Although this is the classic method, there is some controversy as to whether the outer diameter of the airway should be used instead [37]. Pediatric guidelines recommends using a BAR of >0.8 to define bronchiectasis (instead of the adult cutoff of >1 or >1.5) [8,38].

-Signet ring sign – The airway dilation also results in a characteristic "signet ring" sign (image 2), in which the dilated airway appears as a ring and the adjacent artery resembles a protruding signet or jewel.

-Bronchial wall thickening is often present (image 3).

-Other abnormalities associated with bronchiectasis include: a lack of bronchial tapering (from central to periphery), "tram track" lines (depending on the orientation plane), presence of bronchial structures in the lung periphery (image 4), mucus plugging, and mosaic perfusion (reflecting air trapping) [5]. In the acute state, "tree-in-bud" appearance may also be visualised.

-In some cases, the HRCT scan may include a concurrent abnormality related to the underlying disease process associated with bronchiectasis, such as a ground-glass changes reflecting graft-versus-host disease in children with previous transplant (image 5).

False positives of the pathognomonic HRCT abnormality (increased BAR) may occur at high altitude, with asthma, and with reduced pulmonary flow [5]. In children with interstitial lung disease, increased BAR may also be present from pulmonary fibrosis, but patients do not have any symptoms consistent with bronchiectasis. Also, chest CT scans should not be taken to assess the presence of bronchiectasis immediately after an acute infection, as any abnormalities may be reversible.

•MDCT with HRCT – Combining MDCT with HRCT has significantly better sensitivity than conventional HRCT in detecting bronchiectasis and should be used when available [39,40]. Accordingly, the European Respiratory Society Clinical Practice Guideline recommends MDCT with HRCT as the primary imaging modality for diagnosing bronchiectasis in children and adolescents [8].

•Magnetic resonance imaging (MRI) – MRI has been proposed as an alternative to evaluate small airway disease. However, MRI provides a relatively blurred image (compared with images acquired from HRCT) and can only detect moderate to severe airway abnormalities [41]. MRIs cannot be used to exclude the presence of bronchiectasis. Whether or not MRI can be used for monitoring disease (as opposed to diagnosis) remains to be determined.

●Defining severity of radiographic bronchiectasis – Historically, bronchiectasis severity was classified as cylindrical, varicose (or fusiform), and cystic (or saccular) (figure 2), based on the classical appearance of each stage on bronchography [42]. Such appearances are also evident on CT (image 2 and image 4 and image 6), although the definition of varicose versus saccular may not be as clear on axial plane compared with coronal or sagittal planes.

Various scores have been developed to define severity of bronchiectasis based on HRCT findings, such as the Bhalla [43], Reiff [44], or Webb [45] scores. In each of these, higher scores reflect larger BAR and increasing bronchiectasis severity. These scores correlate with progression from cylindrical to cystic changes. They are used primarily in research on bronchiectasis in patients with or without cystic fibrosis [46,47].

●Distribution – Bronchiectasis may be focal or generalized (table 3). These characteristics provide clues to the cause but are not reliable and also depend upon the imaging modality; advanced imaging tends to detect more diffuse disease compared with conventional radiographs.

Spirometry — All children with suspected or confirmed bronchiectasis should be evaluated with spirometry at diagnosis and with serial measures in follow-up [8,38]. The typical spirometric abnormality in bronchiectasis is an obstructive pattern, in which the forced expiratory volume in one second (FEV₁) is low and normal forced vital capacity (FVC) is normal (figure 3) [14,18]. However, in some children with bronchiectasis, a restrictive pattern may be seen (figure 4). Whether the restrictive pattern reflects poor lung growth or bronchiectasis per se has not been established.

Spirometry has limited sensitivity for defining and/or monitoring the severity of bronchiectasis. In children with mild or cylindrical bronchiectasis, spirometry may be normal and may not correlate with radiographic assessment of severity (figure 5) [46,48,49]. As an example, in a study involving 67 Turkish children with bronchiectasis, quality-of-life scores were more closely correlated with clinical symptoms (wheezing and dyspnea) than with spirometry indices [28]. The correlation is better for children with moderate to severe bronchiectasis, in whom spirometry is consistently abnormal [14] and generally correlates with severity, as determined by HRCT and prognosis (based on data from adults [7]).

Serial spirometry can be used to monitor the functional consequences of bronchiectasis, which may worsen over time [50,51], but can also remain stable [52], improve [53,54], or even normalize [55] if the bronchiectasis is diagnosed early and optimally treated.

Other pulmonary function tests may be useful for selected patients (eg, if an asthmatic component of symptoms is suspected but cannot be established with office spirometry). (See 'Special pulmonary function tests' below.)

DIAGNOSIS — Bronchiectasis is suspected in a child with chronic respiratory symptoms (especially chronic wet cough) or signs of severe respiratory disease (digital clubbing or hemoptysis) that are not otherwise explained (table 1). It is more likely in children with risk factors for bronchiectasis, including established or suspected immunodeficiency or history of recurrent pneumonias or protracted bacterial bronchitis (PBB), and in children from a population with high rates of recurrent respiratory infection. (See 'Clinical manifestations' above.)

The diagnosis of bronchiectasis is established by the finding of abnormally dilated bronchi on imaging, typically high-resolution computed tomography (HRCT) with or without multidetector CT (MDCT). (See 'Imaging' above.)

FURTHER EVALUATION

Laboratory studies for all patients — In addition to the imaging tests and spirometry described above, all patients with bronchiectasis should have the following basic panel of tests to screen for an underlying cause, as recommended in consensus guidelines [8,38]:

●Sweat chloride test – This should be performed for all children because neonatal screening can miss the diagnosis of cystic fibrosis.

●Complete blood count and immunologic tests (total immunoglobulin G, A, M, and E [IgG, IgA, IgM, IgE] specific antibodies to vaccine antigens) – This panel serves as an initial screen for some relatively common primary immunodeficiency disorders, such as common variable immunodeficiency and hyper-IgE syndrome.

●Lower airway bacteriology – Bacterial cultures are needed to guide a targeted antibiotic regimen [8,38]. Sputum is the preferred lower airway specimen but may be difficult to obtain from young children, even when induced with normal or hypertonic saline nebulization. Oropharyngeal and nasopharyngeal swab samples have been suggested as an alternative, but results from these specimens may not accurately predict lower airway bacteriology [56]. Therefore, bronchoalveolar lavage may be required to obtain an accurate lower airway specimen in some patients. For bronchioalveolar lavage specimens, a diagnostic threshold of ≥10⁴ colony-forming units/mL of microorganism is typically used to define a clinically relevant infection in children with bronchiectasis [57], based on limited data.

Other tests for selected patients

Tests to determine the cause — Other tests may be needed to determine the cause of the bronchiectasis and are selected based on the child's clinical presentation (table 2) [8]. The etiologies vary among cohorts depending on risk factors. As an example, a rare immunodeficiency may be more likely in a population with consanguinity or founder mutations, but the evaluation requires in-depth immune and/or genetic testing [58] that may not be available in some settings.

Examples of targeted evaluations include:

●In-depth immunologic assessments for children with evidence of immunodeficiency (in consultation with a pediatric immunologist) (see "Approach to the child with recurrent infections")

●Diagnostic bronchoscopy to assess for large airway obstruction with bronchoalveolar lavage for microbiology in children with focal findings on imaging or suspected foreign body aspiration and/or if lower airway specimens are needed for bacteriology.

●Tests for swallowing dysfunction and aspiration in children with risk factors such as neurologic impairment or feeding problems (see "Aspiration due to swallowing dysfunction in children")

●Testing for primary ciliary dyskinesia in a child with neonatal respiratory distress, recurrent upper and lower respiratory infections, and/or situs inversus (see "Primary ciliary dyskinesia (immotile-cilia syndrome)")

●Evaluation for gastroesophageal disease in children with frequent regurgitation or heartburn (see "Clinical manifestations and diagnosis of gastroesophageal reflux disease in children and adolescents")

●Genetics assessment for children with congenital anomalies or syndromic features or a known or suspected genetic disorder (refer to appropriate topic reviews)

●Tuberculosis testing or HIV screening in selected settings (eg, where tuberculosis or HIV have a high prevalence and/or there is a history of close contact with tuberculosis) (see "Tuberculosis disease in children: Epidemiology, clinical manifestations, and diagnosis" and "Epidemiology of pediatric HIV infection" and "Screening and diagnostic testing for HIV infection")

Special pulmonary function tests — A variety of specialized pulmonary function tests are available, although the more complex tests (eg, static lung volumes, lung clearance index, forced oscillatory test) are only available in specialist hospitals and/or research units.

Some patients with bronchiectasis have an asthma phenotype that coexists or complicates the clinical management [24]. In many cases, the asthma can be demonstrated by standard spirometry (ie, an obstructive pattern that reverses with bronchodilatory administration). In selected cases in which spirometry is unclear, an airway hyperresponsiveness or bronchoprovocation test (eg, mannitol or methacholine challenge) may be useful. While lower airway eosinophilia is found in some children with bronchiectasis [59], the utility of fractional exhaled nitric oxide (FeNO; a biomarker for lower airway eosinophilia) has not yet been examined in children with bronchiectasis. Details on the evaluation and diagnosis of asthma are discussed separately. (See "Overview of pulmonary function testing in children" and "Pulmonary function testing in asthma" and "Asthma in children younger than 12 years: Initial evaluation and diagnosis".)

Measures of static lung volume and diffusion capacity (specialized pulmonary function tests used in pulmonology clinics) have not been well studied in children with bronchiectasis. Static lung volume (and, specifically, increased residual volume) is more closely correlated with radiographic assessment of bronchiectasis severity than it is with spirometry, based on data from children with primary ciliary dyskinesia [60]. In adults with bronchiectasis, reduced total lung capacity and diffusion capacity are associated with increased mortality [61]. Reduced exercise capacity (on cycle ergometry and aerobic capacity) has been described in children with bronchiectasis but does not correlate with severity of bronchiectasis, based on HRCT scores [47,62].

In research, lung clearance index is used as an outcome measure in some studies of children with cystic fibrosis but appears to be less useful in other populations with bronchiectasis [63]. Further, this test is not feasible for routine clinical practice, because it requires specialized equipment, technical expertise, and time.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Bronchiectasis" and "Society guideline links: Hemoptysis" and "Society guideline links: Primary ciliary dyskinesia".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topics (see "Patient education: Coughing up blood (The Basics)" and "Patient education: Bronchiectasis in children (The Basics)")

SUMMARY AND RECOMMENDATIONS

●Definition and causes – Bronchiectasis in children is defined as the presence of abnormal bronchial dilatation on chest computed tomography (CT) scans in combination with a clinical syndrome of recurrent or persistent wet/productive cough, airway infection, and/or inflammation. It is the end result of a variety of illnesses, including congenital malformations, cystic fibrosis, primary immunodeficiencies, retained airway foreign body, or postinfectious processes (table 2). (See 'Definition' above and "Bronchiectasis in children: Pathophysiology and causes".)

●Clinical manifestations – Children and youth with bronchiectasis can present with a variety of nonspecific symptoms and signs, the most common of which is a chronic cough that sounds wet and/or is productive of mucus (table 1). Those with advanced disease may develop dyspnea, hemoptysis, and/or digital clubbing. (See 'Clinical manifestations' above.)

●Evaluation and diagnosis – The initial evaluation for a child with suspected bronchiectasis includes a focused medical history and physical examination; chest radiograph; high-resolution CT (HRCT), ideally with multidetector CT (MDCT); and spirometry. (See 'Initial evaluation of suspected bronchiectasis' above.)

•Imaging – The diagnosis of bronchiectasis is confirmed if HRCT demonstrates abnormally dilated bronchi (image 2 and image 3 and image 4). (See 'Imaging' above.)

•Spirometry – Spirometry should be performed at diagnosis and with serial measures in follow-up. The typical spirometric abnormality in bronchiectasis is an obstructive pattern where the forced expiratory volume in one second (FEV₁) is low, with preserved forced vital capacity (FVC) (figure 3). Spirometry can be normal in mild disease (figure 5) or can show a restrictive pattern. (See 'Spirometry' above.)

●Laboratory testing – In addition to the imaging tests and spirometry, all patients with bronchiectasis should have a basic panel of tests, including sweat chloride, complete blood count and immunologic tests (total immunoglobulin G, A, M, and E [IgG, IgA, IgM, IgE], specific antibodies to vaccine antigens), and lower airway bacteriology (on sputum or sample from bronchoalveolar lavage). These tests screen for an underlying cause and guide antibiotic therapy. Other tests may be needed to determine the cause of the bronchiectasis and are selected based on the child's clinical presentation (table 2 and table 3). (See 'Further evaluation' above.)

ACKNOWLEDGMENTS — The UpToDate editorial staff acknowledges Khoulood Fakhoury, MD, and Adaobi Kanu, MD, who contributed to an earlier version of this topic review.