Cough in Children: A Merck Manual of Patient Symptoms podcast

Cough is a reflex that helps clear the airways of secretions, protects the airway from foreign body aspiration, and can be the manifesting symptom of a disease. Cough is one of the most common complaints for which parents bring their children to a health care practitioner.

Etiology

Causes of cough differ depending on whether the symptoms are acute (< 4 wk) or chronic (see Table 17: Approach to the Care of Normal Infants and Children: Some Causes of Cough in Children).

For acute cough, the most common cause is

• Viral URI

For chronic cough, the most common causes are

• Asthma (most common)
• Gastroesophageal reflux disorder (GERD)
• Postnasal drip

Foreign body aspiration and diseases such as cystic fibrosis and primary ciliary dyskinesia are less common, although they can all result in persistent cough.

Table 17
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Some Causes of Cough in Children Cause Suggestive Findings Diagnostic Approach Acute Bacterial tracheitis (rare) URI-like prodrome, stridor, barky cough, high fever, respiratory distress, toxic appearance, purulent secretions Anteroposterior and lateral neck x-rays Bronchiolitis Rhinitis, tachypnea, wheezing, crackles, retractions, nasal flaring, possible posttussive emesis, paroxysmal cough In infants up to 24 mo; most common among those 3–6 mo Clinical evaluation Sometimes chest x-ray and nasal swab for viral culture Croup URI-like prodrome, barky cough (worsening at night), stridor, nasal flaring, retractions, tachypnea Clinical evaluation Sometimes neck and chest x-ray Environmental pulmonary toxicants Exposure to tobacco smoke, perfume, or ambient pollutants Clinical evaluation Epiglottitis (rare) Abrupt onset, high fever, irritability, marked anxiety, respiratory distress, drooling, toxic appearance If patient is stable and clinical suspicion is low, lateral neck x-ray Otherwise, examination in operating room with laryngoscopy Foreign body Sudden onset of cough and choking No fever initially No URI prodrome Chest x-ray (inspiratory and expiratory views) Sometimes bronchoscopy Pneumonia (viral, bacterial) Viral: Wheezing, fever, retractions, staccato-like or paroxysmal cough, possible muscle soreness Bacterial: Rales, decreased breath sounds, retractions, ill-appearing, fever, chest pain, possible stomach pain or vomiting Signs of consolidation (E to A changes, dullness to percussion) Chest x-ray URI Rhinorrhea, red swollen nasal mucosa, possible fever and sore throat, shotty cervical adenopathy (many small nontender nodes) Clinical evaluation Chronic* Airway lesions (tracheomalacia, TEF) Tracheomalacia: Congenital stridor or barky cough, possible respiratory distress TEF: History of polyhydramnios (if accompanied by esophageal atresia), cough or respiratory distress with feeding, recurrent pneumonia Tracheomalacia: CT or MRI Sometimes bronchoscopy TEF: Attempt passage of a catheter into the stomach (helps in diagnosis of TEF with esophageal atresia) Chest x-ray Bronchoscopy and endoscopy Asthma Intermittent episodes of cough with exercise, allergens, or weather changes; URI Family history of asthma History of eczema, nighttime cough Wheezing, decreased breath sounds, retractions Clinical evaluation Trial of asthma drugs Pulmonary function tests Atypical pneumonia (mycoplasma, Chlamydia) Gradual onset of illness Headache, malaise, muscle soreness Possible ear pain, rhinitis, and sore throat Possible wheezing and crackles Persistent staccato cough Chest x-ray Complement fixation test (IgM, IgG) Cold agglutinins test Chlamydia pneumoniae testing controversial, but serologic test (MIF test) most commonly used Cystic fibrosis History of meconium ileus, recurrent pneumonia, failure to thrive, sinusitis, steatorrhea, foul-smelling stools, clubbing or cyanosis of nail beds Sweat chloride test Molecular diagnosis with direct mutation analysis Foreign body History of sudden onset of cough and choking, prolonged cough Possible development of fever No URI prodrome Presence of small objects or toys near child Chest x-ray (inspiratory and expiratory views) Bronchoscopy Gastroesophageal reflux Infants and toddlers: History of spitting up after feedings, arching of the back (Sandifer's syndrome), cough when lying down Older children and adolescents: Chest pain or heartburn after meals and lying down, possible wheezing, hoarseness, nausea, regurgitation Infants: Clinical evaluation Sometimes upper GI x-ray for determination of anatomy Trial of H2 blockers Possible esophageal pH probe and swallowing study Older children: Clinical evaluation Trial of H2 blockers or proton pump inhibitors Possible endoscopy Pertussis (parapertussis) 1–2 wk catarrhal phase of mild URI symptoms, progression to paroxysmal cough, difficulty eating, apneic episodes in infants, inspiratory whoop in older children, posttussive emesis Intranasal specimen for bacterial culture and PCR Postnasal drip (allergic) Headache, itchy eyes, sore throat, pale nasal turbinates, cobblestoning of posterior oropharynx, history of allergies, nightly cough Trial of antihistamine Postrespiratory tract infection History of respiratory infection followed by a persistent, staccato cough Clinical evaluation Primary ciliary dyskinesia History of repeated respiratory infections, and frequent sinusitis Chest CT (characteristic findings include hyperinflation, peribronchial thickening, atelectasis, bronchiectasis, situs inversus) Microscopic examination of living tissue for cilia abnormalities Psychogenic cough Persistent barky cough, possibly prominent during classes and absent during play and at night No fevers or other symptoms Clinical evaluation TB History of exposure Immunocompromise Most children are asymptomatic Atypical symptoms: Weight loss, growth delay, fever, night sweats, chills PPD *All patients require a chest x-ray when they present for the first time with chronic cough. MIF = microimmunofluorescent; TEF = tracheoesophageal fistula. Some Causes of Cough in Children Cause Suggestive Findings Diagnostic Approach Acute Bacterial tracheitis (rare) URI-like prodrome, stridor, barky cough, high fever, respiratory distress, toxic appearance, purulent secretions Anteroposterior and lateral neck x-rays Bronchiolitis Rhinitis, tachypnea, wheezing, crackles, retractions, nasal flaring, possible posttussive emesis, paroxysmal cough In infants up to 24 mo; most common among those 3–6 mo Clinical evaluation Sometimes chest x-ray and nasal swab for viral culture Croup URI-like prodrome, barky cough (worsening at night), stridor, nasal flaring, retractions, tachypnea Clinical evaluation Sometimes neck and chest x-ray Environmental pulmonary toxicants Exposure to tobacco smoke, perfume, or ambient pollutants Clinical evaluation Epiglottitis (rare) Abrupt onset, high fever, irritability, marked anxiety, respiratory distress, drooling, toxic appearance If patient is stable and clinical suspicion is low, lateral neck x-ray Otherwise, examination in operating room with laryngoscopy Foreign body Sudden onset of cough and choking No fever initially No URI prodrome Chest x-ray (inspiratory and expiratory views) Sometimes bronchoscopy Pneumonia (viral, bacterial) Viral: Wheezing, fever, retractions, staccato-like or paroxysmal cough, possible muscle soreness Bacterial: Rales, decreased breath sounds, retractions, ill-appearing, fever, chest pain, possible stomach pain or vomiting Signs of consolidation (E to A changes, dullness to percussion) Chest x-ray URI Rhinorrhea, red swollen nasal mucosa, possible fever and sore throat, shotty cervical adenopathy (many small nontender nodes) Clinical evaluation Chronic* Airway lesions (tracheomalacia, TEF) Tracheomalacia: Congenital stridor or barky cough, possible respiratory distress TEF: History of polyhydramnios (if accompanied by esophageal atresia), cough or respiratory distress with feeding, recurrent pneumonia Tracheomalacia: CT or MRI Sometimes bronchoscopy TEF: Attempt passage of a catheter into the stomach (helps in diagnosis of TEF with esophageal atresia) Chest x-ray Bronchoscopy and endoscopy Asthma Intermittent episodes of cough with exercise, allergens, or weather changes; URI Family history of asthma History of eczema, nighttime cough Wheezing, decreased breath sounds, retractions Clinical evaluation Trial of asthma drugs Pulmonary function tests Atypical pneumonia (mycoplasma, Chlamydia) Gradual onset of illness Headache, malaise, muscle soreness Possible ear pain, rhinitis, and sore throat Possible wheezing and crackles Persistent staccato cough Chest x-ray Complement fixation test (IgM, IgG) Cold agglutinins test Chlamydia pneumoniae testing controversial, but serologic test (MIF test) most commonly used Cystic fibrosis History of meconium ileus, recurrent pneumonia, failure to thrive, sinusitis, steatorrhea, foul-smelling stools, clubbing or cyanosis of nail beds Sweat chloride test Molecular diagnosis with direct mutation analysis Foreign body History of sudden onset of cough and choking, prolonged cough Possible development of fever No URI prodrome Presence of small objects or toys near child Chest x-ray (inspiratory and expiratory views) Bronchoscopy Gastroesophageal reflux Infants and toddlers: History of spitting up after feedings, arching of the back (Sandifer's syndrome), cough when lying down Older children and adolescents: Chest pain or heartburn after meals and lying down, possible wheezing, hoarseness, nausea, regurgitation Infants: Clinical evaluation Sometimes upper GI x-ray for determination of anatomy Trial of H2 blockers Possible esophageal pH probe and swallowing study Older children: Clinical evaluation Trial of H2 blockers or proton pump inhibitors Possible endoscopy Pertussis (parapertussis) 1–2 wk catarrhal phase of mild URI symptoms, progression to paroxysmal cough, difficulty eating, apneic episodes in infants, inspiratory whoop in older children, posttussive emesis Intranasal specimen for bacterial culture and PCR Postnasal drip (allergic) Headache, itchy eyes, sore throat, pale nasal turbinates, cobblestoning of posterior oropharynx, history of allergies, nightly cough Trial of antihistamine Postrespiratory tract infection History of respiratory infection followed by a persistent, staccato cough Clinical evaluation Primary ciliary dyskinesia History of repeated respiratory infections, and frequent sinusitis Chest CT (characteristic findings include hyperinflation, peribronchial thickening, atelectasis, bronchiectasis, situs inversus) Microscopic examination of living tissue for cilia abnormalities Psychogenic cough Persistent barky cough, possibly prominent during classes and absent during play and at night No fevers or other symptoms Clinical evaluation TB History of exposure Immunocompromise Most children are asymptomatic Atypical symptoms: Weight loss, growth delay, fever, night sweats, chills PPD *All patients require a chest x-ray when they present for the first time with chronic cough. MIF = microimmunofluorescent; TEF = tracheoesophageal fistula.

Evaluation

History: History of present illness should cover duration and quality of cough (barky, staccato, paroxysmal) and onset (sudden or indolent). The physician should ask about associated symptoms, some of which are ubiquitous (eg, runny nose, sore throat, fever). Other associated symptoms suggest a cause; they include headache, itchy eyes, and sore throat (postnasal drip); wheezing and cough with exertion (asthma); night sweats (TB); posttussive emesis, spitting up after feedings, or apparent discomfort or arching with lying down (GERD). For children 6 mo to 4 yr, the parents should be asked about potential for foreign body aspiration, including older siblings or visitors with small toys, access to small objects, and consumption of small, smooth foods (eg, peanuts, grapes).

Review of systems should note symptoms of possible causes, including abdominal pain (some bacterial pneumonias), weight loss or poor weight gain and foul-smelling stools (cystic fibrosis), and muscle soreness (possible association with viral illness or atypical pneumonia but usually not with bacterial pneumonia).

Past medical history should cover recent respiratory infections, repeated pneumonias, history of known allergies or asthma, risk factors for TB (eg, exposure to person who has known or suspected TB infection, exposure to prisons, HIV infection, travel to or immigration from countries that have endemic infection), and exposure to respiratory irritants.

Physical examination: Vital signs, including respiratory rate, temperature, and O₂ saturation, should be noted. Signs of respiratory distress (eg, nasal flaring, intercostal retractions, cyanosis, grunting, stridor, marked anxiety) should be noted.

Head and neck examination should focus on presence and amount of nasal discharge and the condition of the nasal turbinates (pale, boggy, or inflamed). The pharynx should be checked for postnasal drip.

The cervical and supraclavicular areas should be inspected and palpated for lymphadenopathy.

Lung examination focuses on presence of stridor, wheezing, rales, rhonchi, decreased breath sounds, and signs of consolidation (eg, egophony, E to A change, dullness to percussion).

Abdominal examination should focus on presence of abdominal pain, especially in the upper quadrants (indicating possible left or right lower lobe pneumonia).

Examination of extremities should note clubbing or cyanosis of nail beds (cystic fibrosis).

Red flags: The following findings are of particular concern:

• Cyanosis or hypoxia on pulse oximetry
• Stridor
• Respiratory distress
• Toxic appearance
• Abnormal lung examination

Interpretation of findings: Clinical findings frequently indicate a specific cause (see Table 17: Approach to the Care of Normal Infants and Children: Some Causes of Cough in Children); the distinction between acute and chronic cough is particularly helpful.

Other characteristics of the cough are helpful but less specific. A barky cough suggests croup or tracheitis; it can also be characteristic of psychogenic cough or a postrespiratory tract infection cough. A staccato cough is consistent with a viral or atypical pneumonia. A paroxysmal cough is characteristic of pertussis or certain viral pneumonias (adenovirus). Failure to thrive or weight loss can occur with TB or cystic fibrosis. Nighttime cough can indicate postnasal drip or asthma. Coughing at the beginning of sleep and in the morning with waking usually indicates sinusitis; coughing in the middle of the night is more consistent with asthma. In young children with sudden cough and no fever or URI symptoms, the examiner should have a high index of suspicion for foreign body aspiration.

Testing: Children with red flag findings should have pulse oximetry and chest x-ray, as should those whose symptoms are prolonged (eg, > 4 wk) or worsening.

Children with stridor, drooling, fever, and marked anxiety need to be evaluated for epiglottitis, typically in the operating room by an ENT specialist prepared to immediately place an endotracheal or tracheostomy tube. If foreign body aspiration is suspected, chest x-ray with inspiratory and expiratory views should be done.

Children with TB risk factors or weight loss should have a chest x-ray and PPD testing for TB.

Children with repeated episodes of pneumonia, poor growth, or foul-smelling stools should have a chest x-ray and sweat testing for cystic fibrosis.

Acute cough in children with URI symptoms and no red flag findings is usually caused by a viral infection, and testing is rarely indicated. Many other children without red flag findings have a presumptive diagnosis after the history and physical examination. Testing is not necessary in such cases; however, if empiric treatment has been instituted and has not been successful, testing may be necessary. For example, if allergic sinusitis is suspected and treated with an antihistamine that does not alleviate symptoms, a head CT may be necessary for further evaluation. Suspected GERD unsuccessfully treated with an H₂ blocker may require evaluation with a pH probe and a swallowing study.

Treatment

Treatment is management of the underlying disorder. For example, antibiotics should be given for bacterial pneumonia; bronchodilators and anti-inflammatory drugs should be given for asthma. Children with viral infections should receive supportive care, including O₂ and bronchodilators as needed.

Little evidence exists to support the use of cough suppressants and mucolytic agents. Coughing is an important mechanism for clearing secretions from the airways and can assist in recovery from respiratory infections. Use of nonspecific drugs for cough suppression is discouraged in children.

Key Points

• Clinical diagnosis is usually adequate.
• A high index of suspicion for foreign body aspiration is needed if children are age 6 mo to 4 yr.
• Antitussives and expectorants lack proof of effect in most cases.
• Chest x-rays should be taken in patients with red flag findings or chronic cough.

Last full review/revision February 2010 by Eve R. Colson, MD; Rachel L. Chapman, MD; Melissa R. Held, MD

Content last modified February 2012