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 weeks) or chronic (> 4 weeks). (See table Some Causes of Cough in Children.)
For acute cough, the most common cause is
For chronic cough, the most common causes are
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Asthma (most common)
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Postnasal drip
Foreign body aspiration and diseases such as cystic fibrosis and primary ciliary dyskinesia are less common, but they can all result in persistent cough.
Some Causes of Cough in Children
Cause |
Suggestive Findings |
Diagnostic Approach |
Acute |
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Bacterial tracheitis (rare) |
URI-like prodrome, stridor, barky cough, high fever, respiratory distress, toxic appearance, purulent secretions |
Anteroposterior and lateral neck x-rays Possibly bronchoscopy |
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Rhinorrhea, tachypnea, wheezing, crackles, retractions, nasal flaring, possible posttussive emesis In infants up to 24 months; most common among those 3–6 months |
Clinical evaluation Sometimes chest x-ray Sometimes nasal swab for rapid viral antigen assays or viral culture |
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URI-like prodrome, barky cough (worsening at night), stridor, nasal flaring, retractions, tachypnea |
Clinical evaluation Sometimes anteroposterior and lateral neck x-rays |
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Exposure to tobacco smoke, perfume, or ambient pollutants |
Clinical evaluation |
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Epiglottitis (rare) |
Abrupt onset, high fever, irritability, marked anxiety, stridor, respiratory distress, drooling, toxic appearance |
If patient is stable and clinical suspicion is low, lateral neck x-ray Otherwise, examination in operating room with direct laryngoscopy |
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Foreign body |
Sudden onset of cough and/or choking No fever initially No URI prodrome |
Chest x-ray (inspiratory and expiratory views) Sometimes bronchoscopy |
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Pneumonia (viral, bacterial) |
Viral: URI prodrome, fever, wheezing, staccato-like or paroxysmal cough, possible muscle soreness or pleuritic chest pain Possible increased work of breathing, diffuse crackles, rhonchi, or wheezing Bacterial: Fever, ill appearance, chest pain, shortness of breath, possible stomach pain or vomiting Signs of focal consolidation including localized crackles, rhonchi, decreased breath sounds, egophony, and dullness to percussion |
Chest x-ray |
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Coughing at the beginning of sleep or in the morning with waking Sometimes nasal discharge, congestion; pain on either side of the nose; pain in the forehead, upper jaw, teeth, or between the eyes; headache and sore throat |
Clinical evaluation Sometimes CT |
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Rhinorrhea, red swollen nasal mucosa, possible fever and sore throat, shotty cervical adenopathy (many small nontender nodes) |
Clinical evaluation |
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Chronic* |
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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: Airway fluoroscopy and/or bronchoscopy TEF: Attempt passage of a catheter into the stomach (helps in diagnosis of TEF with esophageal atresia) Chest x-ray Contrast swallowing study, including esophagography Bronchoscopy and endoscopy |
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Intermittent episodes of cough with exercise, allergens, weather changes, or URIs Nighttime cough Family history of asthma History of eczema or allergic rhinitis |
Clinical evaluation Trial of asthma drugs Pulmonary function tests |
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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 Polymerase chain reaction testing |
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Birth defects of the lungs (eg, congenital adenomatoid malformation) |
Several episodes of pneumonia in the same part of the lungs |
Chest x-ray Sometimes CT or MRI |
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History of meconium ileus, recurrent pneumonia or wheezing, failure to thrive, foul-smelling stools, clubbing or cyanosis of nail beds |
Sweat chloride test Molecular diagnosis with direct mutation analysis |
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Foreign body |
History of acute onset of cough and choking followed by a period of persistent cough Possible development of fever No URI prodrome Presence of small objects or toys near child |
Chest x-ray (inspiratory and expiratory views) Bronchoscopy |
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Gastroesophageal reflux |
Infants and toddlers: History of spitting up after feedings, irritability with feeding, stiffening and arching of the back (Sandifer syndrome), failure to thrive, recurrent wheezing or pneumonia (see Gastroesophageal Reflux in Infants) Older children and adolescents: Chest pain or heartburn after meals and lying down, nighttime cough, wheezing, hoarseness, halitosis, water brash, nausea, abdominal pain, regurgitation (see Gastroesophageal Reflux Disease) |
Infants: Clinical evaluation Sometimes upper gastrointestinal study for determination of anatomy Trial of H2 blockers or a proton pump inhibitor Possible esophageal pH or impedance probe study Older children: Clinical evaluation Trial of H2 blockers or proton pump inhibitors Possible endoscopy |
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1–2 weeks 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 polymerase chain reaction testing |
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Allergic rhinitis with postnasal drip |
Headache, itchy eyes, sore throat, pale nasal turbinates, cobblestoning of posterior oropharynx, history of allergies, nighttime cough |
Trial of antihistamine and/or intranasal corticosteroids Possible trial of a leukotriene inhibitor |
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Postrespiratory tract infection |
History of respiratory infection followed by a persistent, staccato cough |
Clinical evaluation |
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Primary ciliary dyskinesia |
History of repeated upper (otitis media, sinusitis) and lower (pneumonia) respiratory tract infections |
Chest x-ray Sinus x-ray or CT Chest CT Microscopic examination of living tissue (typically from sinus or airway mucosa) for cilia abnormalities |
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Psychogenic cough |
Persistent barky cough, possibly prominent during classes and absent during play and at night No fevers or other symptoms |
Clinical evaluation |
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History or risk of exposure Immunocompromise Sometimes fever, chills, night sweats, lymphadenopathy, weight loss |
Tuberculin skin test (PPD) Sputum culture (or morning gastric aspirate culture for children < 5 years) Interferon-gamma release assay (especially if there is a history of bacille Calmette-Guérin [BCG] vaccination) Chest x-ray |
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* All patients require a chest x-ray when they present for the first time with chronic cough. |
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TEF = tracheoesophageal fistula; URI = upper respiratory infection. |
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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 these symptoms are ubiquitous (eg, runny nose, sore throat, fever); others may suggest a specific cause: headache, itchy eyes, and sore throat (postnasal drip); wheezing and cough with exertion (asthma); night sweats (tuberculosis [TB]); and spitting up, irritability, or arching of the back after feedings in infants (gastroesophageal reflux). For children 6 months to 6 years, 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 a 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 oxygen 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, crackles, 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
Interpretation of findings
Clinical findings frequently indicate a specific cause (see Table: Some Causes of Cough in Children); the distinction between acute and chronic cough is particularly helpful although it is important to note that many disorders that cause chronic cough begin acutely and patients may present before 4 weeks have passed.
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. All children with chronic cough require a chest x-ray.
Children with stridor, drooling, fever, and marked anxiety need to be evaluated for epiglottitis, typically in the operating room by an ear, nose, and throat 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 (or in some centers a chest CT).
Children with TB risk factors or weight loss should have a chest x-ray and purified protein derivative (PPD) testing.
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 upper respiratory infection 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 Gastroesophageal reflux disorder unsuccessfully treated with an H2 blocker and/or proton pump inhibitor may require evaluation with a pH or impedance probe study or endoscopy.
Treatment
Treatment of cough 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 oxygen and/or 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.
