SYMPTOMS

What is childhood cough? What are its symptoms?

Childhood cough is a common symptom of respiratory diseases in children, caused by the reflexive defensive action of the airways due to irritation from foreign objects or secretions in the respiratory mucosa. The main symptom is coughing, which may be dry or productive, and may be accompanied by sore throat, headache, fever, fatigue, etc. Cough caused by allergies may also present with nasal congestion, runny nose, and sneezing.

Coughing helps clear respiratory secretions and some airway obstructions, but prolonged, frequent, or severe coughing can disrupt normal learning, daily life, and rest, and may even lead to throat pain, hoarseness, or respiratory muscle pain. Persistent severe coughing in individuals with underlying conditions may cause complications such as the spread of respiratory infections, bleeding, spontaneous pneumothorax, or even cerebral hemorrhage.

Childhood cough is not simply a smaller version of adult cough; it has unique characteristics. Acute cough in children can be caused by various factors, with viral respiratory infections being the most common cause.

The top three causes of chronic cough in children are allergic cough, upper airway cough syndrome, and post-infectious cough^[1]. Frequent coughing can negatively impact children's learning, activities, and rest, increase anxiety, and harm their physical and mental health, requiring timely and appropriate intervention by doctors and parents.

What are the differences between childhood cough and adult cough?

The differences between childhood cough and adult cough are as follows^[2]:

• The definition of chronic cough in children is a duration of >4 weeks, while in adults, it is >8 weeks.
• The prevalence of chronic cough in adults is about 10%, with regional variations—higher in areas with severe air pollution. Representative data on childhood prevalence is lacking, but literature reports range from 1% to 12%.
• The common causes of childhood cough and adult cough differ. The most common causes in children include variant asthma, infectious cough, and chronic bacterial bronchitis, while upper airway cough syndrome, gastroesophageal reflux disease, and asthma are more common in adults.
• The evaluation criteria for childhood cough and adult cough differ during medical visits, with doctors conducting more detailed history-taking and physical examinations for children.
• Treatment approaches for childhood and adult cough vary, such as differences in medication types and dosages for the same condition.

TREATMENT

What are some ways to relieve children's cough?

The following measures can be taken to alleviate a child's cough:

• If the child has a severe cough with phlegm obstructing the airways and difficulty expelling it, older children who can take medication on their own may use expectorants such as ambroxol hydrochloride oral solution or acetylcysteine granules. However, it should be noted that if the cough is caused by asthma, it cannot be cured by expectorants alone, and medical attention should be sought promptly^[3].
• Ensure proper indoor ventilation and maintain a clean environment to reduce irritation from dust and pathogens. Using a humidifier or placing a basin of water indoors can increase air humidity, moisten the respiratory mucosa, and help relieve coughing.
• Encourage the child to drink warm water, which helps dilute phlegm and promote its expulsion. Increased water intake also accelerates circulation and metabolism, aiding in recovery.
• If the child's airway is severely blocked by phlegm, parents can gently pat the child's back to assist in expelling the phlegm.
• Adequate rest aids recovery. Parents should avoid taking the child to crowded, poorly ventilated places to prevent exposure to secondhand smoke, dust, or pathogens that may worsen coughing.

Note: If these measures fail to relieve the cough or if it worsens, seek medical attention promptly. Tests such as blood work or chest X-rays may be needed to rule out pneumonia.

If an infection is confirmed, targeted treatment such as antibiotics may be required. Simple symptomatic relief is insufficient—the underlying cause must be addressed.

DIAGNOSIS

Under what circumstances should a child with cough seek medical attention?

A child with cough should go to the hospital under the following circumstances:

• Cough accompanied by high fever (above 38°C), insomnia, or loss of appetite, which may indicate pneumonia. Special attention should be paid to possible COVID-19 infection, and immediate medical care is required.
• Paroxysmal choking cough, severe in intensity, accompanied by difficulty breathing, hypoxia, suffocation, or wheezing, which may indicate foreign body aspiration. Immediate medical attention is necessary.
• Cough accompanied by rapid breathing, hypoxia, or even cyanosis (bluish discoloration of the skin or mucous membranes), with signs of retractions (neck, chest, or intercostal indrawing during inhalation). Immediate medical care is required.
• Cough accompanied by abnormal growth and development, with clubbing of fingers or toes (enlarged, drumstick-like appearance), which may indicate severe lung disease or congenital heart disease. Immediate medical attention is necessary.
• Cough accompanied by purulent sputum or hemoptysis (coughing up blood). Timely medical consultation is advised.

In settings such as kindergartens or schools, if cough occurs in clusters, prompt medical consultation is recommended.

Under what circumstances can a child with cough be observed at home without immediate medical attention?

• Mild cough after exercise or stress.
• Brief cough occurring only in the morning.
• Cough accompanied by low-grade fever (36.5°C–38°C) and excessive phlegm, but with good energy levels, likely caused by a common cold. In such cases, focus on reducing fever first, then address the cough after the fever subsides.

Which departments should be consulted for a child's cough?

Pediatrics, Emergency Medicine, or Psychology.

What tests might be required for a child's cough during a medical visit?

• Medical history and physical examination: The doctor will inquire about the child's medical history in detail, conduct a thorough physical examination (including auscultation of the lungs with a stethoscope), and assess growth, development, and any physical abnormalities.
• Imaging tests: Including chest X-rays, chest CT scans, and possibly sinus CT or MRI to rule out structural abnormalities in the upper/lower respiratory tract or heart.
• Pulmonary function tests: Including standard spirometry. The child will wear a nose clip and breathe through a mouthpiece connected to specialized equipment. For suspected asthma, bronchial provocation or bronchodilator tests may be performed.
• Bronchoscopy: Recommended if airway malformation, foreign body (including endogenous airway obstructions or mucus plugs), or similar conditions are suspected.

POTENTIAL DISEASES

Classification and Causes of Pediatric Cough

According to China's pediatric cough guidelines, cough in children is classified based on duration into acute cough, protracted cough, and chronic cough, in addition to psychogenic cough. This classification aids in analyzing the underlying causes. Pediatric cough is typically caused by the following factors^[4,5]:

1. Acute cough: Lasts less than 2 weeks, often caused by upper or lower respiratory tract infections due to various microorganisms or acute asthma attacks.

   • Most children have a history of cold or respiratory infection, accompanied by symptoms such as nasal congestion, runny nose, sore throat, or even fever. Physical examination may reveal enlarged tonsils, and some children may have lung crackles.
   • The spectrum of infectious microorganisms varies slightly by age group. Viral infections are common in infants and toddlers, while Mycoplasma pneumoniae is predominant in preschool and school-aged children.
   • A barking cough, resembling a harsh dog-like sound, is often acute and caused by epiglottis or larynx disorders or tracheal compression, commonly seen in acute laryngitis or epiglottitis, and occasionally in psychogenic cough.

2. Protracted (or subacute) cough: Lasts more than 2 weeks but less than 4 weeks. Besides respiratory infections, it may occur in bacterial sinusitis or asthma. Patients often have a dry cough without phlegm, though a few may produce sputum. Imaging may show thickened or disordered lung markings.

3. Chronic cough: Lasts more than 4 weeks and is divided into specific and nonspecific cough in children.

   • Specific cough refers to chronic cough caused by underlying abnormalities or diseases, most commonly asthma, protracted bacterial bronchitis, chronic suppurative lung disease, bronchiectasis, airway abnormalities (congenital, foreign body, or tumor), aspiration, chronic or rare infections, interstitial lung disease, or extrapulmonary causes (e.g., cardiac abnormalities, ear disorders).
   • Nonspecific cough refers to chronic cough where imaging shows no abnormalities and no clear cause is identified after evaluation. It includes cough-variant asthma, upper airway cough syndrome (e.g., chronic rhinitis, chronic pharyngitis, sinusitis, adenoid hypertrophy), post-infectious cough, allergic cough, gastroesophageal reflux-related cough, and functional cough (e.g., habitual cough or tic disorder).
   • Some congenital conditions, such as vascular anomalies, mediastinal tumors, ciliary dyskinesia, tracheomalacia, or tracheoesophageal fistula, may also cause chronic cough.

4. Psychogenic cough: Also called habit cough, it is typically worse during the day and may present as barking or honking sounds, or throat-clearing. Coughing decreases during enjoyable activities but worsens with attention from parents, teachers, or doctors. Diagnosis is confirmed if symptoms improve after psychotherapy.

How to Prevent Pediatric Cough?

• Prevent cough by avoiding colds. Parents should keep children warm, ensure proper ventilation at home, encourage physical exercise, and take children outdoors regularly to boost immunity.
• Avoid crowded or poorly ventilated places to reduce exposure to cough-causing infections.
• Limit cold, greasy, or spicy foods and minimize snacks.
• Ensure adequate sleep and a regular diet.
• Consider influenza vaccination to prevent flu-related cough.