Dry cough, Chronic cough causes and treatment

Cough is one of the most common reasons for adults seeking medical treatment.
Coughing is a protective reflex mechanism. Cough clears breathing passages from irritants, foreign particles and microbes.
Cough can be dry or productive. A productive cough produces phlegm or mucus, clearing it from the lungs. A nonproductive cough, also known as a dry cough, doesn't produce phlegm or mucus.
Cough can be chronic or acute.
Acute cough is self limiting usually within 3 weeks.
The most common causes of acute cough in adults are an acute viral upper respiratory infection, also known as the common cold, and acute bronchitis. If cough lasts more then 6 weeks it is called chronic cough.
Most patients with chronic cough, present with a dry or minimally productive cough.
So, dry cough most commonly is chronic problem.
Chronic cough can be caused many different conditions, but most common causes include:
upper airway cough syndrome (postnasal drip syndrome), which means, when mucus from your nose, or sinuses drips down the back of your throat.
Gastroesophageal reflux disease, and Asthma.
70 % of chronic cough are caused by these 3 diseases.
In many cases, Cough can be psychogenic and idiopathic (or unexplained).

Chronic cough can be only symptom for asthma. Cough increases especially at night.
Caugh can be caused by Sensitization of cough receptors by inflammatory mediators.
Or Stimulation of cough receptors through constriction of the bronchial smooth muscle.
treatment for patients with cough-variant asthma include, long-acting bronchodilators, antileukotrienes, and or, low-dose theophylline.
Gastroesophageal reflux disease is reported as a cause of chronic cough in as many as 40% of the patients.
Such Patients also complain of typical and frequent gastrointestinal symptoms, such as, heartburn and regurgitation.
Gastroesophageal reflux disease causes cough by 3 mechanisms:
Intraesophageal reflux, (stimulation of the esophageal-tracheobronchial cough reflex), laryngopharyngeal reflux, and microaspiration.
It is important to note that, up to 75% of the cases, patients with GERD-related cough may present with no gastrointestinal symptoms.
Treatment: anti-reflux diet and lifestyle changes, a prokinetic agent (e.g. metoclopramide), and an acid suppressant with a proton pump inhibitor.
In case of postnasal drip syndrome, treatment is dependent on underlying cause.
Antibiotics, in case of sinusitis. Antihistamines in case of allergic rhinitis. Also, avoidance of allergens or irritating factors
When cough reflex is unexplained, and treatment against the potential aggravating factors is not satisfactory. Antitussive medications can be used. The common centrally acting antitussive agents: Codeine, pholcodine, dextromethorphan, methadone, and morphine.
They exhibit their action directly on the cough center in the brain and decrease the nerve impulse discharges to the muscles that produce cough.
First generation antihistamines like chlorpheniramine and centrally acting opioid derivatives like codeine are often used alone or in combination in the management of nonspecific cough.
In children, for acute cough, no effective treatment exist. There is tentative evidence that the use of honey is better than no treatment or diphenhydramine in decreasing coughing.
It does not alleviate coughing to the same extent as dextromethorphan, but it shortens the cough duration better than placebo and salbutamol.
Using honey for infants aged up to 12 months is not advised because of poor immunity against bacteria that may be present, which can cause paralysis.
By BruceBlaus - File:GERD.png, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=56634664
By Mahdy Fouad - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=53115107