Cough

Causes of Cough

Infections:

• Acute – e.g. Laryngitis, tracheitis, bronchitis, bronchiolitis, pneumonia. Whooping cough.
• Chronic – e.g. Pulmonary tuberculosis, chronic bronchitis, chronic laryngitis, bronchiectasis, lung abscess.

Mechanical irritation:

• Inhalation of dust (specifically in pneumoconiosis), irritant gases, chemical fumes or pungent smells, Tobacco smoking.
• Foreign body in larynx or bronchi.
• Post-nasal drip in chronic sinusitis.
• Gastro-esophageal reflux.
• Compression of air passages – (i) Extramural – Aortic aneurysm, pulmonary neoplasm, mediastinal masses, enlarged LA in mitral stenosis. (ii) Intramural – Bronchogenic carcinoma or adenoma, foreign bodies, bronchospasm (asthma), granulomatous endobronchial disease.
• Pressure or tension on air passages – Pulmonary Oedema, interstitial fibrosis, atelectasis, pericardial effusion, pneumothorax.

Reflex – From reflex irritation of vagus:

• Wax in external ear or otitis media.
• Distention of stomach or rarely of colon.
• Sub diaphragmatic abscess or liver abscess.

Thermal stimulus:

• Inhalation of cold air especially in asthmatics and those with intercurrent infection.

Habit cough:

• When a patient has suffered from some prolonged illness in which cough has been a prominent feature, the cough may at times persist as a habit long after the cause has ceased to operate.

Psychogenic cough:

• May be a form of obsessional neurosis or coordinated tic.

Iatrogenic:

• ACE inhibitors, steroid aerosols [1]

Pathophysiology of Cough

• A cough is a protective reflex in healthy individuals which is influenced by psychological.
• The cough reflex is initiated by stimulation of two different classes of afferent nerves, namely the myelinated rapidly adapting receptors, and nonmyelinated C-fibers with endings in the lung. 

Classification of Cough

Dry or unproductive: Upper respiratory tract infection, early stage of pulmonary tuberculosis, bronchogenic carcinoma, smoker’s cough, interstitial fibrosis, bronchial asthma, tropical eosinophilia, pulmonary infarction, etc., Psychogenic or habitual cough.

Wet or productive: Bronchiectasis, lung abscess, fungal infections.

Paroxysmal: Bronchial asthma, cardiac failure, whooping cough.

With wheezing: Bronchial asthma, tropical eosinophilia, chronic bronchitis.

Barking: Harsh, loud, ‘seal-like’ cough, paroxysmal or occasional, in hysteria (functional) disturbing to the hearer, but perhaps not to the patient himself or herself.

Nocturnal in asthma, pulmonary Oedema, post-nasal drip in chronic sinusitis, reflux esophagitis.

Bovine :(Brassy or gander, or leopard’s growl) – due to laryngeal paralysis from involvement of recurrent laryngeal nerve e.g. in aortic aneurysm.

Staccato: In whooping cough there is paroxysmal cough ending in a whoop.

Croupy: Harsh, hoarse cough in laryngeal infection.

Hacking: Short, dry, irritable cough frequently repeated in congestive conditions of pharynx, upper air passages, and smoker’s cough.

Suppressed and painful: In pleurisy cough is suppressed because chest pain is aggravated by coughing (and deep breathing).

Toneless, whispering, aphonic cough: In destructive lesions of vocal cords, e.g., tuberculous ulcer or neoplasm.

Spluttering in trachea: Esophageal fistula.

Cough related to exertion: In early LV failure and mitral stenosis.

Cough related to meals: Suggests hiatal hernia, tracheoesophageal fistula, or esophageal diverticula.

Early morning cough with expectoration in bronchiectasis and pulmonary TB.

Nocturnal cough: LV failure, bronchial asthma, chronic bronchitis, aspiration, post-nasal drip, GERD, esophageal obstruction, ACE inhibitors.

Recent worsening in case of chronic cough is a common presenting symptom of bronchial carcinoma.[1]

Sign & Symptoms of Cough

• A runny or stuffy nose
• A feeling of liquid running down the back of your throat (in other words, postnasal drip)
• Frequent throat clearing and sore throat
• Hoarseness
• Wheezing also shortness of breath
• Either Heartburn or a sour taste in your mouth
• Occasionally, coughing up blood
• Symptoms of nasopharyngeal disease should be assessed, including postnasal drip, sneezing, also rhinorrhea.
• Lastly, GERD may be suggested by heartburn, hoarseness, and frequent eructation. [3][4]

Clinical / Physical Examination For Cough

• In brief, On physical examination, signs of cardiopulmonary diseases should be assessed, including adventitious lung sounds and digital clubbing.
• Examination of the nasal passages, posterior pharyngeal wall, auditory canals, also tympanic membranes should be performed.[4]

Diagnosis of Cough

• Laboratory evaluation should include chest radiography.
• Furthermore, Spirometry with bronchodilator testing can assess for reversible airflow obstruction.
• In detail, With normal spirometry, methacholine challenge testing can be used to assess for asthma.
• Purulent sputum should be sent for routine bacterial also possibly mycobacterial cultures.
• Besides this, Sputum cytology can reveal malignant cells in lung cancer and eosinophils in eosinophilic bronchitis.
• Esophageal either pH probes or radio transmitter capsules can be used to assess for GERD.
• Lastly, Chest CT should be considered in pts with normal chest radiographs who fail to improve with treatment.[4]

Differential Diagnosis of Cough

• Upper airway cough syndrome (i.e. UACS; postnasal drip)
• Asthma
• Gastroesophageal reflux disease (in other words, GERD)
• Non asthmatic eosinophilic bronchitis (in other words, NAEB)
• Chronic bronchitis/COPD
• Angiotensin-converting enzyme inhibitor (i.e. ACE inhibitor)
• Pneumonia
• Post infectious cough

Treatment of  Cough

• Treatment of cause where possible.
• Cough suppressants – for dry cough. Diamorphine, methadone, codeine, or pholcodine in form of linctus. Dry cough in bronchial asthma responds to β-agonist inhalation.
• Expectorants – Mucolytic drugs such as bromhexine, guaifenesin, acetylcysteine, carbocisteine reduce sputum viscosity and help expectoration.
• Treating a cough will depend on what is causing the cough. If you have an infection, your healthcare provider might prescribe some type of antibiotic or antiviral medication, but most viral coughs do not require antiviral medications.
• For GERD, they might suggest diet changes or prescribe a proton pump inhibitor or an H2 blocker.
• Water can be good for a cough. Drinking it can help ease a cough from throat irritation or dryness. Adding it to the air with a vaporizer or a steamy shower are other ways water relieves a cough.
• Quitting smoking and avoiding other irritants are also ways to relieve a cough. Those irritants may include medicines, scents (like perfume or candles), smoke or allergens.[1][5]

Prevention 

Generally, You can prevent some kinds of cough by avoiding irritants that you know cause you to cough.

You can help prevent coughs caused by infections i.e.:

• Getting vaccinated for influenza, COVID-19 and pneumonia.
• Moreover, Avoiding people who are ill.
• Avoid touching your eyes, nose also mouth.
• Lastly, Wash your hands often with soap and water and/or using hand sanitizers.[5]

Complication 

• Cough syncope – Prolonged coughing can reduce venous return, impair cerebral blood flow, thus cerebral oxygenation and result in syncope.
• Rib fracture – especially pathological, e.g., in multiple myeloma, osteoporosis and osteolytic metastasis.
• Spontaneous pneumothorax from rupture of emphysematous bulla.
• Hernia – at weak hernial sites. [1]

Diet & Regimen

• Avoid desserts, soft drinks, fruit juices and all kinds of nectar. Due to sugar in food Increases the risk of inflammation and infection in the body. Make people who are sick with a cold Symptoms do not improve or it may be more severe during the cough, so you should temporarily avoid sweet foods.
• Honey tea, honey may relieve coughs.
• Ginger may ease a dry or asthmatic type, as it has anti-inflammatory properties.
• Fluids Staying hydrated is vital for those with a cough or cold.
• Steam- A wet cough, which is one that produces mucus or phlegm, may improve with steam.
• Salt-water gargle- This simple remedy is one of the most effective for treating a sore throat.
• Bromelain- Bromelain is an enzyme that comes from pineapples. It is most plentiful in the core of the fruit. Bromelain has anti-inflammatory properties and may also have mucolytic properties, which means that it can break down mucus and remove it from the body.
• Probiotics do not directly relieve it, but they may boost the immune system by balancing the bacteria in the gut.[6]