diease

Asthma


OVERVIEW OF 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.


EPIDEMIOLOGY :

asthmatic is common among the people of age group above 65 years.


CAUSES :

The following are the triggering factors for asthma,it includes:

  • Airborne allergens, such as pollen, dust mites, mold spores, pet dander or particles of cockroach waste
  • Respiratory infections, such as the common cold
  • Sinusistis
  • Physical activity
  • Cold air
  • Air pollutants and irritants, such as smoke
  • Certain medications, including beta blockers, aspirin, and nonsteroidal anti-inflammatory drugs, such as ibuprofen (Advil, Motrin IB, others) and naproxen sodium (Aleve)
  • Strong emotions and stress
  • Sulfites and preservatives added to some types of foods and beverages, including shrimp, dried fruit, processed potatoes, beer and wine
  • Gastroesophageal reflux disease (GERD), a condition in which stomach acids back up into your throat


PATHOPHYSIOLOGY :

Asthma is described as an chronic infection which shows inflammation in the pulmonary airway and bronchial hyperresponsiveness to an allergen resulting in asthmatic conditions.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 permeabilty,mucous secretion, bronchospasm, and wheezing.these are the signs of  EARLY ASTHMATIC ATTACK.

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 cells consisting of eosonophis,  mast cells, lymphocytes, monocytes and neutrophils.This is the sign of LATE ASTHMATIC ATTACK.


ROUTES OF TRANSMISSION :

Types of asthma: There are many types of asthma. Listed below are a few of the most common types:

  • Allergic Asthma
  • Bronchial asthma
  • Nocturnal Asthma
  • Occupational Asthma
  • Exercise-Induced Asthma
  • Alcohol induced asthma


COMMON CLINICAL SIGNS AND SYMPTOMS :

 Difficulty in breathing

Wheezing cough

Sneezing

Rapid breathing

Difficulty in speech

Pressure on the chest

  • Risk factor: Having a blood relative with asthma, such as a parent or sibling
  • Having another allergic condition, such as atopic dermatitis — which causes red, itchy skin — or hay fever — which causes a runny nose, congestion and itchy eyes
  • Being overweight
  • Being a smoker
  • Exposure to secondhand smoke
  • Exposure to exhaust fumes or other types of pollution
  • Exposure to occupational triggers, such as chemicals used in farming, hairdressing and manufacturing


DIAGNOSTIC :

Diagnosis : It is easy to diagnose a patient with asthma. There are several tests available to detect the symptoms as asthma triggers. The common tests are spirometry, exhaled nitric oxide and challenge tests.

Spirometry is a type of lung function test that measures how hard a person can blow air out of their lungs. It can determine the level of obstruction in the airway. The test is performed using a machine called a spirometer.

Exhaled nitric oxide is a test that is performed by breathing into a hand-held machine. It then calculates the amount of nitric oxide present in the exhalation. Nitric oxide is produced inside the lungs and is an indicator of inflammation.

Challenge tests are tests which are performed if the other tests are not able to establish a diagnosis of asthma. Challenge tests are of two types – mannitol and methacholine. These agents, when inhaled, causes the airways to narrow only if asthma is present. The test involves the inhalation of these agents in the forms of aerosols or dry powders. If the lung function drops during the challenge, the individual is positive for asthma.

Other diagnostic procedures include:

  • Chest X-rays
  • Other lung function tests.
  • Allergy tests are recommended to detect the exact triggers.

General physical examinations for the functioning of the respiratory system.


TREATMENT AND PROGNOSIS :

Since there is no better cure for asthma the triggering factors such as smoking exposure to pollen can be avoided.If trigger avoidance provides sufficient results then there is no pharmacological treatment is needed in them.If not then administrationnof thebdrug is mandatory.

 Bronchodilator are used for short term recovery.If mild persistent occurs such as teo episodes per week then the administartio of leukotriene antagonist,mast cell inhibitor,corticosteroids are recommeneded. 

Education to the patient regarding the attacks and usage and advantages of pulse oximeter should be conveyed tem and they should be advised to use it periodically.

Lifestyle modification

The triggering factors should be kept in control.the patient should avoid allerens which are lifethretening 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.Mild exercises provide good relief inasthamatic ptients.

Medications

medications are classified as long acting and short acting.

Fast–acting:

Slabutamol is used as inhaler in the treatment of asthmatic attack.They are beta 2 adrenoreceptorand these are the first choice of treatment in asthma.

Ipatropium an anticholinergic medications when used with an SABA provides best results.

Adrenergic agonist such as epinephrine are used in asthmatic attacks but it is contraindicate din cardiac patients.

A shorter course of corticosteroids provides relief and prevents the relapse of the episodes.

Long–term control

Fluticasone propionate metered is used as an inhaler in long term asthmatic attack.

 

  • .Corticosteroids such as beclomethasone provides relief in long term attack.
  • Long acting beta adrenergic (LABA) such as salmetrol or formetrol can improve asthma control, at least in adults, when given in combination with inhaled corticosteroids.
  • Leukotriene receoptor antagonist (anti-leukotriene agents such as montelukast and zafirlukast) may be used in addition to inhaled corticosteroids, typically also in conjunction with a LABA. When these drugs are administered in adjuvant to the corticosteroid they provide relief in moderat and  severe attacks
  • Intravenous administration of the drugs aminophylline  does not provide an improvement in bronchodilation when compared to standard inhaled beta-2 agonist treatment. Aminophylline treatment is associated with more adverse effects compared to inhaled beta-2 agonist treatment.
  • Mast cell inhibitors such as  cromolyn sodium are preferred in case of corticosteroids and they reduces the inflammatory reactions.
  • In paediatric patients long acting beta blockers(LABA) and cinhalational corticosteroids provides an better relief. 
  • . Antocholinergic medications such as Ipatropium bromide are not indicated in long term of treatment in adults.

Delivery methods

Medications are typically provided as metered dose inhalers(MDIs) in combination with an asthma spacer or dry powder inhaler. Spacer is the type of cylinder that mixes the medicines with the air to enhance sthe effectiveness of the intake of the drug .Nebulizers are also used in the treatment with adjuvant to spacers.The main disadavantage of using these medications are oral thrush,inflammation in the mucosa.

Duplimab,Omalizumab are the monoclonal antibodies that are used to treat atopy asthmatic attack.

 

 


PROGNOSIS :

it is a chronic illness and life long patient should be under medications.


PREVENTION :

Avoid coming into contact with the allerrgens

avoid humid climates.


Medicines used in the Treatment :

beclomethasone

Duplimab,Omalizumab

Leukotriene receoptor antagonist (anti-leukotriene agents such as montelukast and zafirlukast

Mast cell inhibitors such as  cromolyn sodium

 


REFERENCE :

http://asthmaticsociety.in

http://medicinenews.in

http://healthline.con

http://who.gov.in