How to evaluate a patient with chronic cough?

Initial evaluation of chronic cough (defined as more than 8 weeks' duration in adults and 4 weeks in children) should include a chest radiography (CXR) in most adult patients.

Patients who are taking an angiotensin-converting enzyme inhibitor (ACEi) should switch to a medication from another drug class.



Differential diagnosis of cough, a simple mnemonic is GREAT BAD CAT TOM. Click here to enlarge the image: (GERD (reflux), Laryngopharyngeal Reflux (LPR), Rhinitis (both allergic and non-allergic) with post-nasal drip (upper airway cough syndrome), Embolism, e.g. PE in adults, Asthma, TB (tuberculosis), Bronchitis, pneumonia, pertussis, Aspiration, e.g foreign body in children, Drugs, e.g. ACE inhibitor, CF in children, Cardiogenic, e.g. mitral stenosis in adults, Achalasia in adults, Thyroid enlargement, e.g. goiter, "Thoughts" (psychogenic), Other causes, Malignancy, e.g. lung cancer in adults).

The most common causes of chronic cough in adults are:

- upper airway cough syndrome (post-nasal drip)
- asthma
- gastroesophageal reflux disease (GERD)
- any combination of the above

If upper airway cough syndrome is suspected, a trial of a decongestant and an antihistamine is warranted.

The diagnosis of asthma can be confirmed with a clinical response to empiric therapy with inhaled bronchodilators or corticosteroids (spirometry is generally preferred though).

Empiric treatment for gastroesophageal reflux disease (GERD) should be initiated in lieu of testing for patients with chronic cough and reflux symptoms.

Patients should avoid exposure to cough-evoking irritants, such as cigarette smoke.

Further testing may be indicated if the cause of chronic cough is not identified and includes:

- high-resolution computed tomography (CT) of the chest
- referral to a pulmonologist or an allergist

In children, a cough lasting longer than 4 weeks is considered chronic.

The most common causes of chronic cough in children are:

- respiratory tract infections ("bronchitis" and pneumonia)
- asthma
- rhinitis with post-nasal drip
- gastroesophageal reflux disease (GERD)
- aspirated foreign body is relatively rare but must not be missed

Evaluation of children with chronic cough should include chest radiography (CXR) and spirometry (if older than 5 years of age). Skin prick test for environmental allergies can also be indicated.

References:

Evaluation of the patient with chronic cough. Benich Iii JJ, Carek PJ. Am Fam Physician. 2011 Oct 15;84(8):887-92.

Diagnosis of chronic cough in children

Vaccines prevent this: Infant girl with whooping cough (Mayo Clinic video)

While the pertussis infection can be mild in adults (often it is quite severe though), if a baby who hasn't received a full course of vaccinations is infected, whooping cough can be extremely serious. Mayo Clinic News reporter has more on how to recognize and treat this potentially deadly disease:



Infant girl with whooping cough -- Mother holding infant girl in Intensive Care Unit. The baby has pertussis (whooping cough) and is coughing severely. Warning: the video is hard to watch.



Everyone should receive the indicated vaccines to prevent potentially deadly diseases such as pertussis.

Acute bronchitis: Many patients expect to be treated with antibiotics and cough meds but this differs from guidelines

Mind map of differential diagnosis of cough. See more Allergy and Immunology mind maps here.

Cough is the most common symptom bringing patients to the primary care physician's office. The most common diagnosis in these patients is acute bronchitis, according to a recent review in the official journal of AFP, American Family Physician.

Acute bronchitis should be differentiated from other common causes of cough such as pneumonia and asthma - because the therapies are clearly different.

Symptoms of acute bronchitis typically last 3 weeks. As we already know, the presence of colored (e.g., yellow or green) sputum does not reliably differentiate between bacterial and viral lower respiratory tract infections. This conclusion was contradicted by a recent study: Green or yellow phlegm likely to be bacterial - confirming beliefs by doctors and patients alike (http://goo.gl/zff8X and http://goo.gl/cwKGs).

Viruses cause more than 90% of acute bronchitis, and therefore, antibiotics are generally not indicated. They should be used only if pertussis is suspected to reduce transmission or if the patient is at increased risk of developing pneumonia (e.g., patients 65 years or older).

The typical therapies that have been traditionally used for managing acute bronchitis symptoms have been shown to be ineffective. The U.S. Food and Drug Administration recommends against using cough and cold preparations in children younger than 6 years.

The supplement pelargonium may help reduce symptom severity in adults.

Many patients expect to be treated with antibiotics and cough medications but this differs from evidence-based recommendations.

The CNN video below tries to decipher what hides behind the names of common cough and cold medications:

References:

Diagnosis and treatment of acute bronchitis. Albert RH. Am Fam Physician. 2010 Dec 1;82(11):1345-50.