Recurrent Croup and Bronchitis
John Welter, MD
•Croup is a viral illness that causes inflammation of the upper airway, which leads to upper-airway obstruction that manifests as barky cough and stridor.
•Recurrent or atypical episodes of croup have many causes and should be distinguished from typical viral croup (see Table 42-1).
—Croup (acute laryngotracheitis)
▪Viral infection of the larynx, trachea, and/or bronchi (most commonly caused by parainfluenza)
▪Typically, viral upper respiratory tract symptoms followed by barky cough, hoarse voice, and stridor
▪Symptoms typically last 2–3 days
▪Symptoms often worse at night
▪Not a specific diagnosis, has many causes
▪Recurrent episodes of barky cough, hoarse voice, and stridor
▪More than 2 episodes of croup per year, often atypical
▪Presence should prompt evaluation for underlying etiologic origin
▪Viral illnesses can unmask the underlying cause
|Table 42-1. Differences Between Croup and Recurrent Croup|
|Age||Commonly 6 mo to 3 y of age, uncommon over 6 y of age||Any age|
|Time of year||Viral illness season (fall, winter)||Any time of year|
|Duration||1–2 days||May last days to weeks, symptoms may persist between episodes|
|Response to treatment||Symptoms typically resolve||Partial or no response|
•Stridor occurs during acute episodes.
—Timing in the respiratory cycle can help distinguish the type of obstruction.
▪Inspiratory: Supraglottic obstruction
▪Biphasic: Glottic and/or subglottic obstruction
▪Expiratory: Tracheal obstruction
•Pharyngeal cobblestoning may be seen in allergic rhinitis and gastroesophageal reflux (GER).
•Wheezing is an indication of lower airway involvement, such as asthma.
•Reduced air entry may indicate an airway foreign body.
•It has been reported that ≤50% of children with subglottic hemangiomas have a facial or neck (beard distribution) cutaneous hemangioma.
•Recurrent croup should prompt obtaining a patient history to identify underlying airway abnormalities.
—Birth history: Intubation in the neonatal period may cause subglottic stenosis that is manifesting as recurrent croup episodes.
—Onset: Early onset before 6 months of age raises suspicion for congenital abnormalities such as tracheomalacia, subglottic hemangioma (which is often steroid responsive), or congenital subglottic stenosis. However, all of these etiologic origins can be causes of recurrent barking cough at any age.
—Quality and volume of voice and crying: A weak cry and/or hoarse voice can be a sign of vocal cord paralysis.
—Dysphagia, recurrent chest infections, and episodes of prolonged cough: These symptoms may be a sign of a vascular ring or other external thoracic compression of the trachea.
—History of foreign-body aspiration: Bronchial foreign bodies may manifest as recurrent croup and are often associated with delayed diagnosis.
•Recurrent croup should also prompt obtaining a patient history to identify associated disorders.
—GER: Symptoms of GER are often present in patients with recurrent croup (occurring 47%–100% of the time).
▪Episodes may improve with treatment; however, the incidence of GER is so high in patients with recurrent croup that other potential etiologic origins should only be discarded with caution.
—Asthma and atopy: Between 40% and 80% of patients with recurrent croup have been reported to have symptoms of asthma and allergies.
—Family history: Children who have a parent with a history of croup are 4.1 times as likely to have recurrent croup than a child whose parents have not had croup.
—On chest radiographs, look for mass effect on the airway, caused by anomalies such as mediastinal masses and radiographically opaque foreign bodies (Figure 42-1).
—Barium esophagography can be used to identify thoracic abnormalities that are causing esophageal and tracheal compression, such as vascular rings, cysts, or neoplasms.
—Computed tomography (CT) or magnetic resonance (MR) imaging of the chest can be used to determine whether mass effect is seen on the airway, suggesting possible vascular ring or mediastinal mass.
Figure 42-1. Vascular ring in a 4-year-old boy. A. Frontal chest radiograph shows mass effect on the right side of the trachea, suggesting a vascular ring (arrow). B. Frontal and C. lateral views from barium esophagraphy demonstrate mass effect on the esophagus at the level of the aortic arch (arrows). D. Coronal reformatted contrast-enhanced computed tomographic image confirms a right arch (arrow on D) with aberrant left subclavian artery.
—Pro: Laryngoscopy can be performed in the ear, nose, and throat office without sedation.
—Con: The subglottic region and trachea cannot be evaluated.
—Laryngomalacia, glottic abnormalities, and signs of GER may be identified.
—The presence of laryngomalacia does not rule out distal airway abnormalities (below the vocal cords).
•Rigid and flexible bronchoscopy performed with anesthesia
—Subglottic, tracheal, and bronchial lesions may be identified, and bronchoscopy is essential for the diagnosis of tracheomalacia.
—With rigid bronchoscopy, tracheomalacia may be underestimated or missed. Flexible bronchoscopy may cause tracheomalacia to be missed, as well, unless it is performed with minimal or light anesthesia in a spontaneously breathing patient.
—Flexible bronchoscopy may cause subglottic hemangiomas to be missed.
—Rigid bronchoscopy can be both diagnostic and therapeutic (ie, removal of foreign bodies).
•Pulmonary function testing
—In older children (typically >5 years of age, but some younger patients may be able to perform testing adequately), inspiratory flows and flow volume loops can help determine the presence, degree, and site of upper-airway obstruction.
•Assess the response to corticosteroids—most commonly dexamethasone— and nebulized epinephrine; consider further evaluation in patients with poor response.
•Assess the patient for asthma and optimally treat both asthma and allergic rhinitis if present (see Chapter 29, Allergic Rhinitis).
•Other treatment is based on the underlying condition.
When to Refer
•Frequent croup (>2 episodes per year)
—Age <6 months or >3 years
—Prolonged episodes beyond 1–2 days
—Hospitalization required, especially for respiratory failure
—No response to standard treatment
•Chronic respiratory symptoms between croup episodes
—Weak cry, hoarse voice
—Frequent lower respiratory tract infections
•Suspicion of foreign-body inhalation
See also Chapter 43, Recurrent Wheezing in Infants, Toddlers, and Preschoolers.
•Cough is one of the most common reasons parents bring their children for medical care.
•Bronchitis manifests as a wet bronchial cough and possibly wheezing caused by both infectious and noninfectious bronchial inflammation.
•Recurrent bronchitis encompasses multiple diseases and is not itself a disease entity.
•More than 2 episodes of cough lasting >10 days should prompt obtaining a further history and evaluation aimed at determining the underlying cause.
•By definition, asthma is a form of bronchitis (see Chapter 30, Asthma Guidelines: Overview).
—While asthma is the most common reason for recurrent bronchitis and therapy directed toward asthma is often successful, asthma can also be overdiagnosed. Without wheezing, it can be dangerous to assume that all children with recurrent coughing have asthma. Lack of response to asthma treatment should prompt evaluation for other causes of recurrent bronchitis.
•Premature infants with subsequent bronchopulmonary dysplasia are prone to prolonged cough and wheeze with viral illnesses that may or may not be inflammatory in nature.
•History of recurrent mild respiratory tract infections (ie, sinusitis, ear infections) or >1 serious systemic infection may be an indication of an immune deficiency.
•Classic cystic fibrosis (CF) typically manifests as failure to thrive, symptoms of fat malabsorption, and chronic cough that is typically responsive to antibiotics. However, some patients may not have symptoms of fat malabsorption.
•Primary ciliary dyskinesia was previously referred to as immotile cilia syndrome.
—Most patients with primary ciliary dyskinesia have a history of chronic or recurrent otitis and/or sinusitis.
—While still considered rare, mild cases have been increasingly recognized with symptoms attributed to asthma for many years, even into adolescence or adulthood.
•Foreign-body aspiration may not elicit a history suggestive of aspiration, which could delay diagnosis.
•Extrinsic airway compression, such as vascular rings, can be associated with dysphagia at times, but not always. Extrinsic airway compression leads to poor bronchial airway clearance and difficulty clearing lower respiratory tract infections.
•In chronic aspiration, neurological weakness or laryngeal anatomic abnormalities can lead to chronic aspiration that places children at risk for recurrent bronchitis.
•Bacterial bronchitis is not common in pediatric patients; however, children with a wet cough for >4 weeks may have evidence of lower-airway bacterial infection at bronchoscopy that is responsive to antibiotics (protracted bacterial bronchitis).
•Consider further diagnostic studies as dictated by the clinical history or if the patient has prolonged or severe episodes that are not responsive to therapy.
•Pulmonary function testing is extremely helpful; it can be used to identify airway obstruction, as well as responsiveness to bronchodilators such as albuterol, which is consistent with the diagnosis of asthma.
—If pulmonary function shows an obstructive pattern after the
use of inhaled albuterol, it is less likely that recurrent bronchitis
can be attributed to asthma alone and should prompt a more extensive workup.
•Radiographic studies may be performed.
—Chest radiography may be used to identify hyperinflation associated with either upper- or lower-airway obstruction, as well as signs of bronchial inflammation or atelectasis.
—If extrinsic airway compression is suspected, barium esophagography may be performed to evaluate the presence of possible vascular ring.
—There is a trend for pediatric radiologists to recommend MR arteriography instead of barium esophagography to evaluate the presence of a possible vascular ring, depending on local resources, including adequate anesthesia support.
—Perform modified barium swallow or flexible endoscopic evaluation of swallow if concerns for aspiration exist.
▪Recurrent aspiration can occur in children who appear otherwise normal neurologically.
—Perform CT of the thorax if there is concern for possible bronchiectasis.
—Still the standard of reference when ruling out CF
—Should always be performed at a Cystic Fibrosis Foundation–accredited laboratory
•Flexible or rigid bronchoscopy
•Treatment of recurrent bronchitis is aimed at the underlying diagnosis.
When to Refer
•Refer the patient to a specialist if there is difficulty establishing the diagnosis.
•Refer if specialized testing, such as bronchoscopy, is needed.
•Refer for interpretation of abnormal pulmonary function test results.
•Refer if the patient is not responding adequately to therapy, particularly if coughing is not resolved within 2–3 weeks at most and/or if a child has a chronic cough, even if mild in nature, in between episodes.
•Barium esophagography is technically dependent, and the radiologist should be alerted to the concern for thoracic compression of the trachea, such as a vascular ring. Many pediatric radiologists suggest MR imaging, MR arteriography, or chest CT, since these modalities provide more information than barium esophagography. In young children, this may vary, depending on resources and availability of pediatric anesthesiology.
•If there is clinical suspicion for CF, then further evaluation, such as sweat testing, should be pursued, even if there is a negative newborn screening result.