Until very recently, when it came to chronic cough, children were to be treated like little adults. In its 1998 guidelines on cough, the American College of Chest Physicians (ACCP) stated that "the approach to managing chronic cough in children is similar to the approach in adults."1
Newly published guidelines from the ACCP take an entirely different view.2 Those guidelines mandate a management approach for children younger than 15 years that is clearly distinct from that for adults. In fact, an entire 23-page article is devoted to the elaboration of the management principles and strategy that are uniquely appropriate for children. What follows here is a summary of the key amendments reflected in these new guidelines.
A first and fundamental difference between the new pediatric and adult guidelines is the definition of chronic cough: in children, this is "a daily cough that lasts longer than 4 weeks" (vs 8 weeks in adults). This time frame is based on a review of the natural history of upper respiratory tract infections in children.
The touchstone of effective management is that treatment should be directed toward the cause of chronic cough. With few exceptions, empiric and symptomatic treatment are strongly discouraged.
Any child with chronic cough needs to be carefully evaluated for symptoms and signs of a systemic or underlying respiratory disease. Sometimes—unlike in adults—specific characteristics of the cough can themselves suggest the diagnosis (Table). Other clinical findings can also offer diagnostic clues.
The guidelines recommend that any evaluation of chronic cough in a pediatric patient include, at a minimum, chest films and spirometry (if age-appropriate). Chronic productive purulent cough is always pathologic, and its evaluation usually includes a number of specialized investigations.
Many suspected causes are actually rare. The guidelines summarize the available evidence on a number of clinical entities that have sometimes been cited as causes of isolated cough in children. These include:
• Upper airway cough syndrome (formerly called postnasal drip syndrome).
• Gastroesophageal reflux disease (GERD).
• Arnold ear-cough reflex.
• Environmental pollutants.
• Pertussis and other respiratory infections.
• Foreign-body aspiration.
• Airway lesions.
All of these entities—even asthma—are, in fact, uncommon causes of isolated cough in children. However, they should not be entirely excluded from the differential diagnosis. This caveat applies in particular to pertussis and foreign-body aspiration, both of which can have serious consequences yet are easily missed.
Two rare causes of cough you don't want to miss. Although pertussis, parapertussis, and Mycoplasma infections typically cause cough with a distinctive pattern or in association with other symptoms, chronic cough may be their sole manifestation. This is especially likely in children who have been vaccinated against pertussis or who have recently received antibiotic therapy. Suspect pertussis in children with persistent cough—even if they are fully immunized—if they have had known contact with a person with pertussis infection.
Because a foreign body lodged in the airway for any length of time can result in long-term pulmonary damage, take pains not to miss this diagnosis. Children who have inhaled a foreign body usually present acutely. However, chronic cough can be the presenting symptom if the diagnosis was missed. Keep in mind that normal findings on a chest radiograph do not rule out foreign-body inhalation.
If evaluation of a child with chronic cough reveals an underlying cause, the cough is said to be specific. Treatment is then directed toward the underlying disease process. However, if no clues to a possible cause are identified, the cough is nonspecific.