Children’s Cough

by Jeff Cersonsky, MD, FAAP

“My four-year-old son has had a cough for two weeks. What does this mean?”

I get this question a lot in the office this time of year. Children are going two, three, or four weeks or longer with a nagging, irritating cough and parents get frustrated trying to get rid of it. Frequently, the child coughs through the night, perhaps not waking him, but the parents worry about his breathing.

Cough is a normal body function designed to forcibly eject material that is partially blocking the airway. Frequently, that material is mucus formed anywhere in the respiratory tract, from the nose to the throat to the lungs. Cough has a job to do and accomplishes that job fairly well, preventing a build-up of mucus in the airway, and hindering any bacteria or viruses in the mucus from infecting the lung tissue and causing pneumonia.

“My child never spits out the mucus. Will he get pneumonia?”

Cough is frequently classified as productive or non-productive (or dry). In actuality, virtually all coughs are productive to some extent. However, the dry cough brings up so little mucus that the child swallows it without even knowing it. Children will frequently swallow the mucus brought up by a productive cough, too. Parents are understandably concerned about this, as the misconception is that the mucus goes back down into the lungs, when it actually ends up in the stomach. Although mucus in the stomach can be irritating to the stomach (and occasionally leads to vomiting), most of the time the mucus is broken down by the stomach and passes through harmlessly. If a child is able, the mucus is best spit out into a tissue. Swallowing the mucus will not cause pneumonia.

“Green mucus means infection, right?”

The nature of the mucus brought up by a cough is also a frequent subject of discussion in the office. One important myth to dispel is that thick or green mucus means bacterial infection in children. Thick or green mucus just means that there is little water in it.

“Why does my child keep his cough so long?”

The cough reflex stimulates an area of the brainstem that controls coughing. Any material in the airway or irritation of the airway wall can cause this reflex. Frequently, an infection causes an area of irritation in the airway (bronchitis, laryngitis, tracheitis, or pharyngitis). Even when the infection is resolved and the virus and bacteria are no longer present, the irritation can persist and the cough continues. The child is cured, but he sure doesn’t sound like he’s cured! By far, this residual irritation is the most common reason that children keep their cough for weeks. Exposure to smoking, allergies, and recurrent respiratory infections can also cause prolonged cough.

“What are the causes of cough? Don’t bad coughs usually require antibiotics?”

Allergy is a common cause of cough. Allergic rhinitis and asthma are the most common illnesses in this category. Specific treatment is indicated – bronchodilators and anti-inflammatories for asthma, and antihistamines or anti-inflammatories for allergic rhinitis. Frequently, allergy can lead to infection, most notably sinusitis.

Cough is frequently caused by infections in the airway which are predominantly viral and do not require antibiotics. Common viral infections include rhinitis (the common cold), pharyngitis (sore throat), laryngitis, tracheitis, bronchitis, and bronchiolitis, none of which should be treated with an antibiotic. Even pneumonia is mostly viral in children, although we usually treat pneumonia with antibiotics because of the risk of missing a bacterial pneumonia. Some infections cause combinations of the above such as croup (laryngotracheobronchitis) and respiratory syncitial virus (RSV), which can cause infection anywhere in the respiratory tract. Aside from pneumonia, there are a few respiratory infections that require antibiotics, including sinusitis, otitis media (yes, the common ear infection is really a respiratory infection), strep throat (which usually does not cause cough), and whooping cough (which can be prevented by the vaccination).

“So what can I give her for cough?”

Since most causes of cough are not treatable with antibiotics, what is a parent to do when her child has a cough? The first step is to consult a pediatrician to determine the most likely cause of the cough. The doctor might prescribe an antihistamine, an antibiotic, an anti-inflammatory, a humidifier, or avoidance of allergens, if indicated. Making a definite diagnosis is frequently difficult, so, if the treatment prescribed does not have the desired effect, the doctor should be contacted again. Assuming the cause is viral and no prescription medication is necessary, a parent then goes to the local pharmacy looking for a “cough medicine.” Most pharmacies have a dizzying array of these tonics, all making different promises. However, they come down to five prime ingredients: expectorants, decongestants, pain killers/fever reducers, antihistamines, and cough suppressants. Expectorants are worthwhile from a psychological effect of feeling like they sooth the airway. Decongestants provide some measure of relief of the nasal congestion accompanying a cold. (Phenylpropanolamine, a drug that’s been in the news lately as having caused strokes in young adults, is an effective decongestant. There is no evidence yet that it causes any significant side effects in children although many are cautiously not recommending its use.) In my opinion, pain killers/fever reducers (acetaminophen and ibuprofen) should be given separately when needed and should not be included in cold or cough medicines. It pays to read the ingredient labels carefully so that one doesn’t double-dose the child. Antihistamines can be effective if the cause is allergy (see above). Cough suppressants are slightly effective in decreasing the cough. The most common ingredient in over-the-counter cough-suppressant medications is dextromethorphan (DM). This ingredient is safe in recommended doses, as it does not paralyze the cough, but can reduce the nagging, unnecessary cough. Diphenhydramine (Benadryl) is also a safe cough-suppressant, although it is usually used as an antihistamine.

Prescription cough medicines are prescription for a reason – they can cause serious side-effects. The most common medicines contain codeine or hydrocodone. These are narcotics that do paralyze the cough reflex in the brainstem and also paralyze the cilia in the airway that help us clear mucus. I rarely prescribe these medications in children, because I fear that the child could lose his ability to clear the mucus, resulting in pneumonia. I would rather see the child continue to cough than get this serious infection.

A parent who is better informed about the nature of cough and its causes can make a better decision on treatment of their child, and is better able to relax when faced with a chronic cough.

(Note: Most of the questions used in my articles are derived from questions I’m asked in my practice. I welcome questions, which can be sent to my e-mail address at jmcdii@erols.com or to my office at 30 Quaker Farms Road, Southbury, CT 06488. I cannot respond to all questions nor give medical direction for specific children, but I can give helpful general advice. Previous articles can be found on my Web site at www.erols.com/jmcsdii/page2.html.)