Every winter, the comment “I just can’t seem to get rid of this cough” permeates conversations.
In fact, coughing is one of the most common complaints for which patients consult their physicians. Fortunately, most coughs are caused by minor upper-respiratory infections, and go away on their own within a month-although the occasional viral cough may persist for up to three months before resolving by itself.
Coughing is a normal protective reflex for the respiratory tract; it helps to rid the lungs of mucus and other secretions, and prevents choking on foreign bodies. A cough becomes chronic and cause for concern when it persists for more than a month. In younger children, especially those under six months, a cough that lasts longer than two weeks should be evaluated by a doctor.
Causes of chronic coughing differ among children, and tend to vary with the age of the child. Possible causes in infancy include:
- Bronchopulmonary dysplasia (abnormal tissue formation in the lungs) usually following respiratory distress syndrome in the newborn period
- Infections, such as pertussis (whooping cough)
- Aspiration (taking into the lungs) of a piece of food or other solid or liquid substance, possibly reflecting a swallowing problem
- Congenital abnormalities of the throat, esophagus, or bronchial passages
- Congestive heart failure associated with congenital heart disease
- Cystic fibrosis
- Exposure to tobacco smoke
In children and adolescents, chronic coughing is most often a result of postnasal drip caused by hay fever or sinusitis. Less often, a chronic cough in an older child is caused by one or more of the following:
- Gastroesophageal reflux (heartburn) in which some of the contents of the stomach back up into the esophagus
- Aspiration of food
- Cigarette smoking
- Psychological factors such as nervous coughing
When a pediatrician or other physician examines an infant’s cough, he or she will first ask the parent questions about birth history, immunization status, and growth patterns. The doctor will want to know whether the child has ever aspirated food or foreign bodies into the lungs, and whether the child has ever had pneumonia or experienced loud, harsh-sounding, labored breathing.
In evaluating children and adolescents with chronic coughs, the physician will investigate symptoms of chronic runny nose. He or she will ask about postnasal drip-frequent clearing of the throat is a sign of this-and the timing of the cough. Does it increase at bedtime or first thing in the morning? The doctor may want to know whether the cough is dry, exacerbated by exercise, triggered by cold air, or brought on by laughter. Other likely questions will cover heartburn, belching, vomiting-and cigarette smoking.
Asthma is a possibility when the cough is dry, occurs at night, or exacerbated by exercise, cold air exposure or laughter. It’s also important to ask questions pertaining to heartburn, regurgitation, and cigarette smoking (which may not be easily admitted).
A cough may be psychological in origin if it sounds like a honk or a bark and is absent when the child is asleep. Often, psychogenic coughing is found in children experiencing social or emotional problems, such as school phobias.
The Physical Exam
After taking a complete history, the physician will perform a physical examination. Blood tests may be ordered, along with a chest or sinus x-ray. The doctor may perform a simple lung-function test, in which the child is asked to exhale forcefully into a plastic tube. Allergy tests may be recommended. The physician may want to look into the lungs with a bronchoscope.
Complications and Treatment
Untreated, a chronic cough may result in several significant complications, from fractured ribs to heart rhythm abnormalities.
Treatment of a cough is most effective when the factor or factors that cause it are identified and addressed. If postnasal drip or asthma are responsible for a cough, for example, the physician will treat those conditions. A cough-suppression medication may also be prescribed. When the cause of the cough is unknown, treatment may include:
- Cough-Suppressing Agents, containing codeine or non-narcotic formulations with dextromethorphan
- Antitussives, such as the analgesic benzonatate, which also suppress coughs
- Expectorants, including water, guaifenesin, ammonium chloride, and iodides, which thin mucus, making it easier to expel from the lungs
Psychogenic cough is a special case. When it is strongly suspected, a reward system for cough control often yields dramatic results.
Chronic coughing should not be a problem. In most cases, coughs will go away by themselves. Coughs that persist can usually be treated successfully.