Pediatric Bronchiectasis 

René Laennec, inventor of the stethoscope, first described bronchiectasis in 1819 while observing patients with tuberculosis and the sequelae of pneumonia in the preantibiotic era. The term bronchiectasis is derived from the Greek bronchion, meaning windpipe, and ektasis, meaning stretched. Bronchiectasis is characterized by the dilatation of bronchi with destruction of elastic and muscular components of their walls.

Bronchiectasis can be focal or diffuse. It is usually due to acute or chronic infection or inflammation, anatomic airway obstruction, or underlying congenital disease that predisposes to chronic infection. The presentation includes recurrent respiratory infections, productive cough, shortness of breath, and occasional hemoptysis. See the images below.

In developing countries, bronchiectasis is still frequently encountered as one of the sequelae of acute infection. In the developed world, immunizations and antibiotics have led to a declining incidence of this disorder. In these countries, diffuse bronchiectasis is more often found in association with underlying disorders such as cystic fibrosis (CF), immune deficiencies (including human immunodeficiency virus [HIV] infection), primary ciliary dyskinesia, and recurrent aspiration syndromes. Focal bronchiectasis is usually associated with bronchial obstruction (ie, from a foreign body) that leads to infection.

Non–cystic fibrosis (CF) bronchiectasis in children presents as a wide spectrum of disease severity. Some children have intermittent symptoms of cough and occasional lower respiratory tract infections. Others experience daily cough and produce purulent fetid sputum, requiring frequent hospitalizations for respiratory exacerbations. (See Clinical.)

Because bronchiectasis is defined as an abnormal dilatation of airways, the diagnosis depends on radiographically or anatomically visualizing the typical changes. In patients with suspected bronchiectasis without characteristic chest radiograph findings, a high-resolution computed tomography (HRCT) scan is the diagnostic procedure of choice (see Workup). Other testing may be indicated to diagnose underlying conditions.

Cough is an almost universal symptom and is frequently described as productive in older children or loose in toddlers and infants. In addition to the treatment of any identified underlying disorder in patients with bronchiectasis, therapy is guided at reducing the airway secretions and facilitating their removal through cough. Pharmacotherapy may be used to enhance bronchodilation and to improve mucociliary clearance. Antibiotics can be used to prevent and treat recurrent infections. Secretions can be mobilized with chest physiotherapy and mucolytic agents. Occasionally, surgery may be considered. (See Treatment.)

This article focuses on children with non-CF bronchiectasis. See Cystic Fibrosis for a more in-depth discussion of CF bronchiectasis and Bronchiectasis for a discussion of this disorder in adults.

Bronchiectasis generally results from obstruction and/or inflammation of the airway. The obstruction and inflammation may be due to any of the underlying disorders listed above or to infection with acute tuberculosis, adenovirus, measles, Mycobacteriumavium, or Aspergillus fumigatus.

Chronic infection can lead to recruitment of neutrophils, T lymphocytes, and monocyte-derived cytokines. The release of inflammatory mediators, elastases, and collagenases leads to inflammation and destruction of elastic and muscular components of bronchial walls. In addition, the outward elastic recoil forces of surrounding lung parenchyma exert traction, which causes expansion of airway diameter. These changes may be accompanied by bronchial arterial proliferation, which predisposes to hemoptysis. Hemoptysis may also occur as a result of the dilating airways impinging on the accompanying blood vessels.

Bronchiectasis associated with bronchial obstruction may have a focal distribution distal to the site of obstruction. Bronchiectasis associated with underlying disease is likely to be diffuse.

Two different types of bronchiectasis are noted: cylindrical, which is presumably more readily reversible if the underlying disorder can be controlled, and saccular, which is less readily reversible even if the underlying disorder is controlled.

Bronchiectasis may result from infection, congenital or acquired disorders, or obstruction. All causes share the same pathophysiologic pathway: ineffective pulmonary toilet and chronic or recurrent infection and inflammation.

Common infectious causes include the following:

• Severe pneumonia, especially viral
• Measles, tuberculosis, pertussis, Adenovirus Mycobacterium avium, and Aspergillus fumigatus infections
• HIV infection: Children who develop lymphocytic interstitial pneumonitis seem at increased risk of subsequent bronchiectasis

Congenital disorders associated with bronchiectasis include the following:

• CF
• Young syndrome
• Ciliary dyskinesia
• Marfan syndrome
• Bruton agammaglobulinemia
• Congenital absence of bronchial muscle (Mounier-Kuhn syndrome) or cartilage (Williams-Campbell syndromes)
• Immunoglobulin A (IgA) and G (IgG) deficiencies and IgG subclass deficiencies, especially IgG2 deficiency

Acquired disorders associated with bronchiectasis include the following:

• Intrinsic airway luminal obstruction by a retained bronchial foreign body^[1] or extrinsic compression by mass
• Chronic aspiration, which is associated with swallowing dysfunction, gastroesophageal reflux disease, or tracheoesophageal fistula
• Connective tissue disorders, including rheumatoid arthritis and systemic lupus erythematosus
• Allergic bronchopulmonary aspergillosis
• Tracheal stenosis with impaired mucociliary clearance
• Severe tracheomalacia or bronchomalacia with impairment of mucociliary clearance
• Fibrosing lung diseases associated with sarcoidosis or idiopathic pulmonary fibrosis
• Persistent atelectasis

United States statistics

Current population-based estimates of occurrence are not available. In 1963, Clark estimated an incidence of 1.06 cases per 10,000 population.^[2] The incidence of bronchiectasis associated with underlying systemic disease reflects the incidence of the particular disease. The most common congenital disease associated with bronchiectasis is CF. One study estimates that 110,000 people in the United States have bronchiectasis, including adults.^[3]

Callahan and associates reported the incidence among Alaskan Native children in the Yuskon-Kuskokwim region to be about 140 cases per 10,000 population.^[4] Redding and colleagues reported the incidence of bronchiectasis in southwest Alaskan Natives is 16 cases per 1,000 population.^[5]

International statistics

In developed countries, the frequency is similar to that in the United States. The frequency is higher in the developing world, where measles, adenovirus infection, pneumonia, tuberculosis, and HIV infection are all on the rise and are associated with bronchiectasis.

In a study from the United Kingdom that started in 1949, Field studied children with bronchiectasis for almost 2 decades and documented a fall in the annual hospitalization rate for bronchiectasis in 5 British hospitals. During the study period, as broad-spectrum antibiotics became widely available, the hospitalization rate decreased from approximately 48 cases per 10,000 population to 10 cases per 10,000 population.^[6]

In New Zealand, Twiss and colleagues reported the incidence of bronchiectasis in children younger than 15 years at 3.7 cases per 100,000 population in 2001-2002.^[7] The incidence was highest among Pacific children, at 17.8 cases per 100,000 population. The incidence was 4.8 cases per 100,000 population in Maori children and 1.5 cases per 100,000 in New Zealand overall, compared with 2.4 cases per 100,000 in other Pacific regions. Most New Zealand children with bronchiectasis developed disease in early childhood and had a delayed diagnosis.

Twiss and colleagues noted that the incidence of bronchiectasis in New Zealand children was nearly twice the rate of CF and 7 times that of bronchiectasis in Finland, which is the only other country reporting a childhood national rate. They further noted that in central Australian aborigines, the incidence is 14 cases per 1,000 population, compared with 0.1 cases per 1,000 in Scotland and 4.9 cases per 1,000,000 in Finnish children.^[7]

Race-, sex-, and age-related demographics

Bronchiectasis is more common in patients of Polynesian and Alaskan Native ancestry. Karadag and associates' study in Turkey suggests possible genetic predisposition in some populations and found that 43% of children with bronchiectasis had parents who were first-degree or second-degree relatives but presumably without any other known underlying disorder.^[8]

Morrissey and colleagues found non-CF bronchiectasis to be more common and more virulent in women. The differences may results from inflammatory-immune, environmental, anatomic, or other genetic factors.^[9]

Karadag and colleagues reported a mean age at presentation of 7.4 ± 3.7 years.^[8] In Field's 1949 survey, 15% of patients presented when younger than 2 years, 43% when aged approximately 2 years, and 92% when younger than 10 years.^[10] These data predate most current immunizations and antibiotics. In Clark's 1963 series, one half of the children developed symptoms when younger than 3 years.^[2]

Overall, the prognosis is good for a child with bronchiectasis. The key to a successful outcome is determining whether the cause of the damage is ongoing (eg, chronic aspiration) and then treating the underlying problem.

Growth of new pulmonary tissue in children proceeds rapidly until about age 6 years and then tapers off through childhood. Injury at an early age may be compensated for by growth of normal healthy lungs in the absence of ongoing damage.

In the absence of an underlying condition, children with isolated bronchiectasis often have a good prognosis. Progressive bronchiectasis from underlying disease (eg, CF) or ongoing pulmonary insult (eg, aspiration syndromes) causes a progressive obstructive defect and, ultimately, respiratory compromise. This may manifest as dyspnea at rest or with exercise or sleep-disordered breathing. Ultimately, patients may experience chronic hypoxemia, pulmonary hypertension, cor pulmonale, hypercarbia, respiratory failure, and death.

Progressive focal disease may lead to progressive infection with fever and abnormal growth. The area may contribute enough ventilation/perfusion mismatch to cause hypoxemia with exercise. Although not yet proven, infected secretions from the abnormal portion of the lung could spill over to other portions of the lung, causing more widespread infection.

Prolonged therapy with systemic or high-dose inhaled corticosteroids may affect growth and increase the risk of other complications of steroids. In patients with non-CF bronchiectasis, prolonged systemic antibiotics may produce a small benefit and reduce sputum volume and purulence but may also be associated with unpleasant side effects.

Karadag and associates illustrated that bronchiectasis remains one of the most common causes of childhood morbidity in developing countries.^[8] Twiss and colleagues recently demonstrated that children with bronchiectasis have significant airway obstruction that deteriorates over time.^[11] However, Karadag and associates demonstrated that children with non-CF bronchiectasis have a much slower decline in lung function than children with CF.^[6] Akalin and colleagues reported decreased left ventricular function and exercise capacity in bronchiectasis.^[12]

Limited mortality data are available. In Field's original group, who were studied at the beginning of the antibiotic era, 4% of children with medically treated bronchiectasis died (mostly from infection), and 3% of children who were surgically treated died (many immediately following or as a late result of surgery) in the ensuing 2 decades.^[10]

Chest physiotherapy and postural drainage are important elements in the treatment of bronchiectasis and should be taught to the child's parents early in the course of disease. This is especially true when the child produces significant amounts of sputum. Physiotherapy techniques should be frequently reviewed and retaught.

For patient education information, see the Bacterial and Viral Infections Center, as well as Tuberculosis.