Cough

last authored: April 2012, David LaPierre
last reviewed:

 

Introduction

Cough is extremely common, being one of the most frequent presenting symptoms in children and adults. It is a protective mechanism to clear the lungs, bronchi, or trachea of irritations and secretions. It also prevents aspiration of foreign materials into the lung, ie from a post-nasal drip or gastric fluid.

 

The differential diagnosis of cough is extensive, ranging from the trivial (physiologic throat clearing) to the potentially lethal (ie pneumonia, congestive heart failure). Careful clinical evaluation is required to ensure the proper diagnosis is made.

 

 

 

The Case of Mr York

Mr York is a 35 year-old man who comes to his family doctor with a worsening cough over the past four months. What questions do you ask him?

return to top

 

 

 

Differential Diagnosis

infectious

viral

 

bacterial

 

fungal

 

respiratory

 

cardiovascular

irritants

 

gastrointestinal

  • GERD
  • diaphragmatic or subdiaphragmatic mass

 

malignancy

 

psychological

  • psychogenic (habitual) cough
  • paradoxical vocal cord dysfunction

 

ear, nose, throat

  • post-nasal drip
  • foreign body in airway, nose, or ear canal
  • middle ear effusion

congenital

pulmonary malformations

  • bronchogenic cysts
  • cystic adenomatoid malformation
  • congenital lobar emphysema
  • pulmonary sequestration

vascular malformations

  • aberrant innominate artery
  • double aortic arch
  • airway hemangioma

gastrointestinal malformation

  • esophageal duplications
  • tracheoesophageal fistula

other

  • congenital immunodeficiency

 

medications

  • beta-blockers
  • ACE inhibitors

return to top

 

 

 

History and Physical Exam

  • history
  • physical exam

History

 

Types of Cough

Stacatto: pertussis or parapertussis

Bark-like: croup

Throat clearing: postnasal drip, sinusitis, allergies

Foghorn-like, only when awake: psychogenic

Present illness:

  • duration?
  • onset: sudden or gradual?
  • frequency?
  • improving or worsening?
  • time of day or night?
  • type of cough?
  • severity?
  • productive? volume, colour, and purulence of sputum?
  • precipitating events: infection, choking, allergies?
  • triggers?
  • fever, malaise
  • chest pain
  • accompanying symptoms - rhinorrhea, watery eyes, hedaches, fever, weight loss, symptoms of malabsorption, wheezing

Triggers for Cough

Cold, exercise, URTI: asthma

Lying down: post-nasal drip, GERD

Eating: GERD, tracheoesophageal fistula

Review of systems

  • chest pain
  • acid reflux
  • constitutional symptoms

 

Past Medical History

  • asthma, COPD
  • GERD/acid reflux
  • sinusitis
  • heart disease
  • previous illnesses or surgery
  • allergies
  • immunizations
  • birth history (especially in children)

 

Medications

  • steriods
  • inhalers
  • anti-reflux medication
  • antihistamines
  • ACE inhibitors

 

Family History

  • asthma
  • allergies
  • cystic fibrosis
  • emphysema
  • sarcoidosis
  • tuberculosis

 

Social history

  • recent travel
  • TB risk factors: country of origin, housing, jail time, homelessness

 

Environmental History

  • cigarette exposure
  • pets
  • condition of home: dust, mold, cockroaches, construction irritants
  • home heating system, especially wood stoves

Physical Exam

 

General appearance

  • height and weight
  • degree of respiratory distress

Skin

  • eczema
  • rashes

HEENT

  • watery eyes
  • ears
  • sinus tenderness
  • nasal discharge or congestion
  • pale or boggy turbinates
  • post-nasal drip
  • pharyngeal cobblestoning (allergies)

Lungs

  • respiratory rate
  • chest appearance
  • breath sounds (rhonchi, crackles, wheezes)
  • symmetrical air expansion

Heart

  • murmur

Extremeties

  • cyanosis
  • clubbing

return to top

 

 

 

Investigations

  • lab investigations
  • diagnostic imaging
  • other

Lab Investigations

Initial workup may include:

  • CBC
  • electrolytes
  • INR/PTT
  • BUN and creatinine

Allergy testing can be done via skin tests.

  • CBC with eosinophilia, or IgE levels, can suggest allergy.
  • radioallergosorbent testing (RAST) is not as sensitive as skin testing

Purified protein derivative (PPD) can be done to rule out tuberculosis.

Sputum culture and gram stain can be done with productive cough, including acid-fast staining if TB is suspected.

Diagnostic Imaging

Chest X ray or CT can evaluate pneumonia, TB, malignancy, sarcoidosis, and other causes of lung disease.

Pulmonary function testing can evaluate the presence of asthma, including in children above age 5. Provocational testing can be done with methacholine or exercise challenges.

return to top

 

 

Management

Diagnosis and treatment (as appropriate) of the underlying cause should be sought in all cases.

 

Treatment of symptoms should be considered when patients are uncomfortable, cannot sleep, or cannot work or study.

Expectorants moisturize airway secretions, assisting with their expectoration (coughing up). Water is the most effective expectorant; another is guaifenesin.

Antitussive medications can act peripherally (diphenhydramine) or centrally (dextromethorphan or codiene).

Mucolytic medications are useful for patients with thick secretions, and include mucomyst and pulmonzyme.

 

return to top

 

 

Pathophysiology

Stimulation of irritant receptors in the pharynx, larynx, trachea, and large bronchi cause cough. Irritants, inflammation, mucous, or mechanical stimulation can all evoke a cough.

return to top

 

 

The Case of little Sam

Sam is a 4 year-old girl with a cough that has lingered since her URTI one month ago (which has otherwise cleared up). She is finding it diffficult to sleep, and her parents are becoming increasingly frustrated.

What treatments do you offer, if any? Are any further investigations required?

return to top

 

 

Additional Resources

 

 

return to top

 

 

Topic Development

created: DLP, Aug 09

authors: DLP, Aug 09

editors:

reviewers:

 

 

return to top