Chronic cough is typically defined as a cough that persists for longer than 8 weeks. Chronic cough is not a disease, it?s a symptom. It is a very common problem, and is one of the most common symptom for which patients see a healthcare provider.

 

Causes

Pathogenic triad of chronic cough

• Upper airways cough syndrome or postnasal drip syndrome
• Bronchial asthma
• Gastro esophageal reflux disease (GERD)

Upper airways cough syndrome (UACS)

UACS refers to the sensation of secretions from the nose or sinuses that drain into the pharynx in addition to nasal discharge and frequent throat clearing.

UACS is considered the most common cause of chronic cough and has been implicated as the cause in up to 85- 87% of patients

It includes

• Chronic sinusitis
• Allergic rhinitis
• Vasomotor rhinitis
• Nonallergic rhinitis with eosinophilia (NARES)
• Post infectious rhinitis
• Allergic fungal sinusitis
• Rhinitis due to anatomic abnormalities
• Rhinitis due to physical or chemical irritants
• Occupational rhinitis
• Rhinitis of pregnancy
• Rhinitis due to medications (decongestants over use)

Bronchial asthma

Its variable air flow obstruction and airway hyper responsiveness which manifests as shortness of breath, wheezing, dyspnea, and cough

The treatment of bronchial asthma, regardless of whether it is of the cough variant or not, includes beta-2 agonists and corticosteroids

Gastro esophageal reflux disease

It’s due to 2 mechanisms

• Esophageal acid exposure that stimulates cough reflex via vagus nerve
• Micro aspirations of esophageal contents in the trachea and bronchi

Other cause

• Bronchiectasis
• Smoking
• Bronchiolitis
• Lung carcinoma
• Chronic aspiration
• Chronic obstructive pulmonary disease (COPD)
• Congestive heart failure (CHF)
• Foreign body
• Interstitial lung disease
• Neuromuscular disorders
• Pertussis
• Psychogenic cough
• Sarcoidosis
• Tracheoesophageal fistula
• Tuberculosis
• Zenker diverticulum
• Esinophillic bronchitis
• Use of ACE inhibitors

Cough associated symptoms

Although chronic cough is usually not serious, it can be associated with a variety of unpleasant effects, including physical exhaustion, self-consciousness, insomnia, headache, dizziness, muscle strain, hoarseness, excessive perspiration, and leakage of urine during coughing.

Tests and diagnosis

• Complete blood count
• Sputum examination and culture
• Chest X-ray
• Pulmonary function test- spirometry
• Bronchoscopy

Treatment

Symptomatic relief

• Cough medications- Expectorants (Guaiphenasin) with antitussives (Dexmethorphan)
• Steam inhalation
• Drink plenty of water while taking expectorants. Fluids will help to break up mucus and clear congestion
• In severe cases Codeine- cough suppressants are prescribed
• Quit smoking
• Avoid exposure to allergens and pollutants
• Patients taking blood pressure medications (ACE inhibitors) need to consult a doctor and later plan the treatment

Cough suppressants

Opiods and derivatives	Benzyl morphine, Codeine, Dihydrocodeine, Dextromethorphan, Heroin, Hydrocodone, Noscapaine, Pholcodeine,
Others	Diphenhydramine, Dimethoxanate, Dibunate, Oxalamine, and others

 

 

Specific therapy

Post nasal drip

• Decongestants (pseudoephedrine) and anti histamine (diphenhydramine)
• Antibiotics to overcome infection
• Nasal inhalers with ipratropium bromide

Chronic variant asthma

• Bronchodilators – Salbutamol, Salmetrol, Deriphylline, and others
• Corticosteroids (inhaled) – Budesenoid, Fluticasone, Betamethasone and others
• Other inhalers- Salbutamol, Ipratropium bromide, and others

GERD

Stop smoking and quit alcohol

Not to skip any meals and to have meals on proper time

Avoid fatty, spicy, junk foods and carbonated drinks

Proton pump inhibitors and H2 antagonists are useful to reduce the reflux .