Chronic coughing has been defined as a cough lasting for 3 weeks or more. The basic tenet is that acute coughing is likely to be a viral or self-limited process, while chronic coughing merits an evaluation for an underlying illness. This distinction, however, is not always simple. Pediatric providers must recognize the child who presents with a cough that is acute yet recurrent—not an uncommon scenario. For example, the child who develops 10 days of “acute” coughing every month still warrants an evaluation for chronic cough.

In a child who has chronic respiratory problems, it is extremely helpful to ask the parent: “Is this the same type of cough your child usually gets with asthma (or allergies, sinusitis, etc.), or is the cough different this time?” It is helpful to see if a pattern to the cough exists and how it fits into the child’s overall health history. Regardless of the duration of the cough, providers must use good clinical judgment to evaluate the severity of the illness.

Ascertaining the time of day that the cough is most severe is one of the most important and helpful tasks. Coughing from postnasal drip can occur at any time but tends to be most prominent when the child first wakes up in the morning. It also may be troublesome when the child first lies down. Bronchospasm is likely to cause a cough that is most annoying in the middle of the night; however, postnasal drip, pertussis, and gastroesophageal reflux also strike at night. On the contrary, the cough that occurs all day—especially during times of stress—yet disappears completely the instant the child falls asleep, may be a habit cough, also called a cough tic or psychogenic cough.

In temperate climates, coughing is a far more common complaint during the winter, especially in those with viral respiratory illnesses, asthma, or sinusitis. Bronchiolitis from respiratory syncytial virus (RSV) usually occurs between October and March but can happen at other times as well. A pattern of coughing in the fall, spring, or both should raise suspicions about allergic rhinitis and allergy-triggered asthma.

Families and providers often point out the nature of the cough, using terms such as dry, moist, loose, tight, barking, honking, or hacking. This element of the history can be helpful but usually is not specific enough to help pin down the diagnosis. Some practitioners have come to label all children with a dry, barking cough as having “croup”. This practice should be avoided unless one is explicitly referring to a specific acute viral illness characterized by inspiratory stridor. Patients diagnosed as having “recurrent croup” are likely to have asthma, postnasal drip, or sinusitis.

Coughing fits, or paroxysms, often followed by post-tussive vomiting are common in patients with pertussis. Similar coughing fits can occur in patients with asthma, bronchiolitis
and other viral infections, sinusitis, and cystic fibrosis (CF).

A loud, brassy cough is seen in patients with cough tic (a habit cough) or tracheomalacia. Many patients with residual tracheomalacia associated with tracheoesophageal fistula will have a troublesome brassy cough. Patients with asthma will often report a change in cough from dry to wet (or tight to loose) as they improve.

Coughing that is triggered primarily by food intake always warrants evaluation. These patients may develop aspiration, laryngospasm, choking, or apnea. Newborns with suck-and-swallow incoordination may cough and sputter upon initiation of feeds, perhaps accompanied by oxyhemoglobin desaturation, cyanosis, or apnea. Patients with neuromuscular disease may have varying degrees of dysphagia, most commonly presenting with respiratory difficulty when drinking thin liquids. Infants or young children with coughing or choking during feeding and a history of stridor or wheezing may have a vascular ring. Babies with an H-type tracheoesophageal fistula may present with aspiration episodes and abdominal distension from swallowing air. Gastroesophageal reflux (GER) may occur at any age but is most likely to elicit respiratory symptoms in infants. The child may cough, choke, or have apnea toward the end of a feed or even an hour or longer afterward. Choking, nasal congestion, arching of the back, drooling, hoarseness, and irritability may characterize the event. The child may appear to be in pain or seem to have a bad taste in the mouth. If there is associated laryngospasm, bronchospasm, or aspiration, the child may have respiratory distress. The diagnosis of GER is more likely when these symptoms occur in association with vomiting.

Finally, children with coughing during feeds accompanied by signs of allergy (eg, rhinitis, conjunctivitis, puffy eyelids, eczema, hives, or wheezing) may have an underlying food allergy. Food allergy is seen most commonly in infants and young children.

Clues to the etiology and significance of the cough may be found in the patient’s personal or family health history or in the environment. Has the child presented with coughing before? If so, what was the cause and what worked to make it better? Equally important, which medications were tried in the past for coughing and did not work? Does the child generally wheeze or go into respiratory distress after the onset of coughing? Does the child have a history of asthma, allergies, or sinusitis?

The child’s past medical patterns are important. It is alarming when a child who was never prone to respiratory problems in the past begins to have such symptoms. While this scenario may only indicate the late onset of asthma or allergies, it also can be the presentation for a collagen vascular disease or an airway tumor. While most providers will consider CF in the child with a cough, failure to thrive, and malabsorption, it is important to remember that CF is quite variable. Ten percent of
patients with CF do not have malabsorption, and some patients with CF are overweight. Table 36-2 lists some important aspects of past medical history and their implications.

Most children with asthma have a positive family history. Uncovering a family history of asthma can be trickier than it seems, however, as many patients are undiagnosed or have been mislabeled as having various forms of chronic or recurrent “bronchitis.” Siblings may have been diagnosed with “recurring croup.” Display 36-1 lists important aspects of the family history to explore.

The environmental history should include the home, neighborhood, school, daycare center or babysitter’s home, as appropriate. It also should include the work site of employed adolescents. If the parents are divorced, there may be two home environments to consider. It is gratifying to cure a chronic cough by making appropriate modifications to the home environment. Display 36-2 lists important aspects of the environmental history.

When ordering a chest radiograph, it is important to order films in both the posterior–anterior (PA) and lateral positions. It is not uncommon to miss findings if only the PA film is ordered. It is always worthwhile to provide the radiologist with clinical information. The chest x-ray may reveal pneumonia, an unsuspected aspirated foreign body, bronchiectasis in a patient with CF, or lymphadenopathy suggestive of TB. Commonly, the chest x-ray may reveal signs of hyperinflation or atelectasis as a result of mucus plugging, findings suggestive of bronchiolitis or asthma. Peribronchial cuffing or central perihilar densities also suggest asthma. The x-ray also may detect pleural disease, interstitial disease, pulmonary edema, congenital pulmonary anomalies, or a mass. If a mass is detected, a chest CT may be useful in further delineating the lesion. Serial radiographs can be helpful in determining whether or not an abnormality is persistent.

Localized hyperinflation suggests an endobronchial foreign body. In such cases, decubitus films, or, in cooperative older children, inspiratory and expiratory films may be ordered to enhance findings of unilateral hyperinflation secondary to a retained foreign body. A mucus plug in the airway due to asthma or bronchiolitis may yield the same radiographic appearance as a foreign body. If the clinical history is suggestive, and there is no history of foreign body aspiration, the provider may elect to treat for asthma and repeat the chest x-ray to see if the localized hyperinflation has disappeared.
A normal chest radiograph can give reassurance, narrow the diagnostic possibilities, and reduce the use of unnecessary antibiotics.

A soft tissue x-ray of the neck can reveal adenoidal hypertrophy or various forms of upper airway obstruction. Sinus films may detect air-fluid levels or opacification, but a sinus CT scan has greater sensitivity for sinus disease and anatomy.

The upper gastrointestinal (GI) series, or barium swallow, is helpful in the child with cough related to feedings. It is less sensitive in detecting GER as the pH probe but can detect associated anatomical problems, such as hiatal hernia, and is very sensitive for cases of vascular ring. Finally, an upper GI series can sometimes detect an H-type tracheo-esophageal fistula, although these are notoriously difficult to find. For obvious reasons, a technician and radiologist accustomed to performing this study on infants and young children should perform the GI series.

A modified barium swallow, or cinefluoroscopy, is helpful in the evaluation of the child who may be aspirating oral feedings. In this study, the patient eats and drinks barium-coated drinks and foods in various textures. Fluoroscopy is performed while the child swallows, so that abnormalities in the swallowing mechanism and any tracheal aspiration can be documented.

The complete blood count (CBC) may reveal an elevated number of eosinophils in patients with asthma, allergies, or chlamydia. Neutrophils will be elevated in bacterial pneumonia, sinusitis, or CF, and lymphocytes will be high in viral illness or pertussis. Quantitative immunoglobulins (IgG, IgA, and IgM) may be useful to measure in the patient with recurring cough and frequent infections. The quantitative subclasses of IgG also can be determined, but there is significant variability in the reliability of results from different laboratories. Serum IgE can be measured to detect allergies. Blood cultures can occasionally establish the etiology of bacterial pneumonia.

Currently, three states perform CF screening in all newborns, and several other states are considering initiating these programs. Elsewhere, testing is ordered when providers suspect the condition. The most sensitive test is the sweat test, which should be ordered whenever a child has a history of repeated lower respiratory infections with or without malabsorption or failure to thrive. Whenever possible, providers should choose a laboratory with extensive experience and credentials for performing the sweat test, such as a Cystic Fibrosis Foundation–accredited laboratory. Genetic testing (mutation analysis) has lower sensitivity, depending on the particular laboratory and the patient’s ethnic background. The reader should refer to Chapter 55 for more information about CF.

Children with a cough from asthma, rhinitis, or sinusitis often have underlying allergies. In the past, referral for allergy testing and desensitization was almost a knee-jerk reaction to a diagnosis of asthma. Today, it is clear that allergy testing and desensitization demonstrate very limited utility for children with asthma. They may be moderately useful for youngsters with allergic rhinitis unresponsive to medical therapy with nonsedating antihistamines and intranasal steroids.

Testing may be warranted in certain situations, such as when the family needs evidence that a family pet is causing the problem or if food allergies are suspected. Skin tests have the greatest sensitivity in detecting allergies. Specific IgE radioallergosorbent technique (RAST) tests are less sensitive and more expensive, particularly if a large panel of tests is requested. Skin or RAST tests should check for the most likely allergens related to the patient’s environmental exposures and seasonal pattern of illness. In young infants, foods are the most likely allergens; the likelihood of environmental allergies increases with age.

A reliable method of tuberculin testing, such as the Mantoux (PPD) test, is a basic part of the evaluation of coughing children. This testing becomes more important if there is a history of exposure, suggestive findings by radiograph, or any documented pneumonia.

By far, the most common etiology for a cough in an otherwise healthy child is an acute respiratory viral illness. The cough in this case is the result of postnasal drip and mucus hypersecretion. The afflicted child may develop a runny or stuffy nose, perhaps some fever, and cough. Generally, the cough is not severe, and the child has minimal interruption in sleep or other daily activities. The child may appear well or only mildly ill. The chest examination will be normal. Often, other family members will be affected as well. The cough generally resolves itself within 10 days and requires no specific treatment. If the fever persists for several days or if the child appears ill or has a marked loss of appetite or persistent vomiting, the provider must consider the possibility of pneumonia, even if the examination is normal.

If the cough is disturbing the child’s sleep or associated with post-tussive vomiting, providers should consider the possibility of asthma or reactive airway disease (RAD). This is true even if the child is not wheezing.

Infants cannot cooperate in taking a deep breath for chest examination, so providers may miss mild wheezing on auscultation. They also can miss wheezing on examination of a screaming, fussy baby. Children may wheeze mainly at nighttime and sound completely clear during the day. Many children with RAD present with a cough and perhaps coarse breath sounds and a prolonged expiratory phase, but no overt wheezing. Finally, patients with severe bronchospasm may not be moving enough air to generate a wheeze.

Young children often show evidence of airway reactivity with nearly every viral respiratory illness. If the cough is disturbing to the patient and family or does not clear up after 10 days, a trial of asthma medications (eg, a bronchodilator, perhaps with a short course of an oral corticosteroid) may be warranted. Another option, if nasal congestion is prominent, is to try a decongestant or antihistamine. Coughing that restricts a child’s sleep, activity, or school attendance and prevents parents from attending work is worth treating. A more detailed discussion of asthma and cough-variant asthma is presented in Chapter 55.

Bronchitis, defined as inflammation of the bronchial epithelium, occurs as part of the clinical spectrum of many different diseases. As such, its existence as an isolated illness is unusual during childhood. Most children who are experiencing bronchial inflammation have antecedent or current viral illness. Inflammation and spasm of the bronchi also occur as part of the spectrum of asthmatic illness. Bordatella pertussis, measles, influenza and diphtheria, can all involve the tracheobronchial airway and as such produce the harsh cough that is observed with inflammation of this part of the respiratory tree. With croup, a relatively common illness in early childhood, there is inflammation of the trachea, bronchi, and larynx. (Please refer to the ensuing discussion of croup.) Environmental allergens, irritants, pollutants, and toxins can also affect the bronchi and cause acute or chronic symptoms.

Croup is technically a syndrome, the hallmark of which is upper airway obstruction and stridor. Congenital airway anomalies, smoke inhalation, postintubation stridor, measles, and diphtheria can all cause a croup syndrome. In common parlance, however, the term croup refers to the most frequently occurring variety, laryngotracheobronchitis (LTB), or viral croup. While most children with LTB have mild illnesses that can be treated at home, the potential exists for severe airway obstruction or even respiratory failure.