diease

Cough


OVERVIEW OF Cough :

 A cough is way of responding when something irritates or triggers the throat and respiratory tract.


CAUSES :

The following causes, alone or in combination, are responsible for the majority of cases of chronic cough:

  • Postnasal drip. When your nose or sinuses produce extra mucus, it can drip down the back of your throat and trigger your cough reflex. This condition is also called upper airway cough syndrome (UACS).
  • Asthma. An asthma-related cough may come and go with the seasons, appear after an upper respiratory tract infection, or become worse when you're exposed to cold air or certain chemicals or fragrances. In one type of asthma (cough-variant asthma), a cough is the main symptom.
  • Gastroesophageal reflux disease (GERD). In this common condition, stomach acid flows back into the tube that connects your stomach and throat (esophagus). The constant irritation can lead to chronic coughing. The coughing, in turn, worsens GERD — a vicious cycle.
  • Infections. A cough can linger long after other symptoms of pneumonia, flu, a cold or other infection of the upper respiratory tract have gone away. A common but under-recognized cause of a chronic cough in adults is pertussis, also known as whooping cough. Chronic cough can also occur with fungal infections of the lung, tuberculosis (TB) infection or lung infection with nontuberculous mycobacterial organisms.
  • Chronic obstructive pulmonary disease (COPD). COPD, a chronic inflammatory lung disease that causes obstructed airflow from the lungs, includes chronic bronchitis and emphysema. Chronic bronchitis can cause a cough that brings up colored sputum. Emphysema causes shortness of breath and damages the air sacs in the lungs (alveoli). Most people with COPD are current or former smokers.
  • Blood pressure drugs. Angiotensin-converting enzyme (ACE) inhibitors, which are commonly prescribed for high blood pressure and heart failure, are known to cause chronic cough in some people.

Less commonly, chronic cough may be caused by:

  • Aspiration (food in adults; foreign bodies in children)
  • Bronchiectasis (damaged, dilated airways)
  • Bronchiolitis (inflammation of the very small airways of the lung)
  • Cystic fibrosis
  • Laryngopharyngeal reflux (stomach acid flows up into the throat)
  • Lung cancer
  • Nonasthmatic eosinophilic bronchitis (airway inflammation not caused by asthma)
  • Sarcoidosis (collections of inflammatory cells in different parts of your body, most commonly the lungs)
  • Idiopathic pulmonary fibrosis (chronic scarring of the lungs due to an unknown cause)

The Gastroesophageal reflux disorder sometimes causes irritation and caused cough.

There are two types of coughs includes wet cough and dry cough. Wet cough brings the mucus out whereas mucus presentation is absent in the dry cough. The dry cough is created by the upper respiratory tract infections.

 


PATHOPHYSIOLOGY :

Pathophysiology:

 

The three main receptors plays a vital role in the cough:

  • Rapidly adapting receptors (RARs) that respond to mechanical stimuli, cigarette smoke, ammonia, acidic and alkaline solutions, hypotonic and hypertonic saline, pulmonary congestion, atelectasis, and bronchoconstriction
  • Slowly adapting receptors (SARs)
  • Nociceptors on C-fibers that respond to chemical stimuli as well as inflammatory and immunological mediators such as histamine, bradykinin, prostaglandins, substance P, capsaicin, and acidic pH

 

It is believed that the cough is caused by the following mechanism due to hypersensitivity reactions:

 

Cough is described as an chronic infection which shows inflammation in the pulmonary airway and

bronchial hyperresponsiveness to an allergen. Inflammatory cells are

accumulated in respiratory bronchioles.

Physiologically, allergen inhaled results in provocation of the inflammatory system of the respiratory

system resulting in increased secreation of inflammatory mediators such as methacalmine and

histamine. Release of histamine from the mast cells results in activation of the prostaglandins and

leukotrienes.In addition to that cytokines are also released from the mast cells which leads to

Increased vascular permeability, mucus secretion, bronchospasm, and wheezing. These leads to the bronchoconstriction and the airway is disturbed which results in cough mechanisms.

Triggering factors that results in blockage of the pulmonary airway include cold air, exercise, viral upper

respiratory infection, cigarette smoke, and respiratory allergens. Bronchial provocation with allergen

induces a prompt early phase immunoglobulin E (IgE)-mediated decrease in bronchial airflow. Initially

there is an increase in the leukocyte count in the pulmonary ares with help of CD4+ cells. The activated

T-lymphocytes also direct the release of inflammatory mediators from eosinophils, mast cells, and

lymphocytes. The cross-linkage of two IgE molecules by allergen causes mast cells to degranulate,

releasing histamine, leukotrienes, and other mediators that perpetuate the airway inflammation.

Histolopathology of the bronchial airway might shows an inflammatory infiltrate consisting

of eosinophils , mast cells, lymphocytes, monocytes, and neutrophils.


COMMON CLINICAL SIGNS AND SYMPTOMS :

Difficulty in breathing

Wheezing cough

Sneezing

Rapid breathing

Difficulty in speech

Pressure on the chest


DIAGNOSTIC :

It is the most common cause of the chronic cough .  avoding environmental irritants and offending antigens, treating sinusitis with antibitics and wearing patients off nasal dcongstants for rhinitis medications. The treatment is with thedecongestants and antihistamines.

Asthma:

Asthma is a chronic condition of the respiratory system in which the airways get blocked and narrowed.the airways get swollen and may produce excess mucus resulting in breathing difficulties and couhing.Nonallergic eosinophilic bronchitis. The asthmatic symptoms include Difficulty in breathing

Wheezing, cough,Sneezing,Rapid breathing,Difficulty in speech,Pressure on the chest

Gastroesophageal reflux disease

Gastroesophageal reflux disorder indicates regurgitation of the acidic content into the esophagus due to the dysfuction of the valve present between the oesophagus and stomach.

The choice of acid suppressive medication can include histamine 2 (H2) blockers, proton pump inhibitors (PPIs), and prokinetic agents.

indicated that treatment of refractory chronic cough with a combination of speech pathology therapy and pregabalin (300 mg daily) is more effective than treatment with speech pathology therapy plus placebo.


TREATMENT AND PROGNOSIS :

Medications used to treat chronic cough may include:

  • Antihistamines, corticosteroids and decongestants. These drugs are standard treatment for allergies and postnasal drip. Antihistamine used in cough includes cromolyn sodium, cetirizine, chlorpheniramine.
  • Inhaled asthma drugs. The most effective treatments for asthma-related cough are corticosteroids and bronchodilators, which reduce inflammation and open up your airways. Theophylline produces better relief.s
  • Antibiotics. If a bacterial, fungal or mycobacterial infection is causing your chronic cough, your doctor may prescribe medications to address the infection. Azithromycin or third generation cephalosporins provides better relief.
  • Acid blockers. When lifestyle changes don't take care of acid reflux, you may be treated with medications that block acid production. Some people need surgery to resolve the problem. Omeprazole or Ranitidine can be used.
  • Opiates such as codeine is used in cough syrup to produce better relief.

 


PROGNOSIS :

The prognosis is excellent.


PREVENTION :

The triggering factors should be kept in control.

the patient should avoid allerens which are lifethreatening to them.

Allergens include smoke,non selective beta blockers,sulfite containing foods and smoking and second hand smokers also called as passive smokers are the reasons for deterioration in the treatment. 

Yoga provide the better relief.

Obesity should be avoided.

If GERD is suspected then proper treatment should be checked.


Recovery Period :

it might take 15-20 days for the cough to subside