Asthma is a Global Health Issue

Asthma is a global health problem

The incidence of this condition is increasing day by day

Globally more than 100 million people are affected 

In Indian 15-20 million peoples are suffering

It is also a killer disease. Worldwide annually more than 180,000 deaths.

Occurrence of asthma is a complex processes which involves a complex interaction between in-utero factors, genetic factors, atopy, viruses and environmental condition etc

Exact Cause is Unknown

It isn’t clear why some people get this condition and others don’t. The causes of is not due to a single factor but may be due to complex interaction of multiple factors including a combination of environmental and genetic (inherited) factors.

Triggers of Asthma

Exposure to various irritants, chemicals and substances (allergens) can trigger symptoms. These triggers include:

• Airborne substances, such as pollen, dust mites, mold spores, pet dander or particles of cockroach waste
• Respiratory infections, such as the common cold
• Cold air
•  Physical activity (exercise-induced asthma)
• Air pollutants and irritants, such as smoke
• Certain medications, including beta blockers, aspirin, ibuprofen etc
• Strong emotions and stress
• Sulfites and preservatives added to some types of foods and beverages, including shrimp, dried fruit etc
• Gastroesophageal reflux disease (GERD)

Factors associated with an increased incidence of asthma

1. Genetic factor:

There are several genes responsible for increased risk. Family history of atopy or some form of allergic disease will increase the likelihood in child.

2. Allergic rhinitis:

Allergic rhinitis is a major risk factor for development. Children who has allergic rhinitis are at increased risk in later life.

3. Allergen sensitization and exposure:

Sensitization to environmental allergen is  strongly linked to childhood asthma. However allergen avoidance measure in already developed case of asthma is a debatable issue and is it advisable to avoid allergen whenever possible.

4. Smoking

Exposure to cigarette smoke is a major risk factor for wheezing illness in children.  Maternal smoking during pregnancy significantly increases the risk of wheezing in early childhood. However these factors may not increase risk of atopic asthma later in life.

Phenotypes of Asthma

Asthma may have cluster of characteristics that define the disease and its subsets. These subsets are the phenotypes . These include:

• Allergic asthma: most common phenotype. This variety often occurred in childhood. There may be past and/or family history of allergic disorders like  such as eczema, allergic rhinitis, or food allergy. This phenotype responded well with inhaled corticosteroid (ICS) treatment.

• Non-allergic asthma: this condition is not associated with allergy.   These type of patient less responded to ICS.

• Pre-asthma wheezing: These phenotypes mainly occur in infant and pre-school children. It may be episodic due to virus or trigger by multiple factors.

• Late-onset asthma: occur in adult, mainly in women. These types require higher dose of ICS.

• Exercise-Induced Bronchospasm (EIB)– here the person started symptoms during exercise.
• Aspirin-Exacerbated Respiratory Disease (AERD): It consists of three clinical entities namely  asthma, recurrent nasal polyp, and sensitivity to aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs).

• Asthma associated with apparent irreversible airflow limitation: Few patients with long-standing cases develop fixed airflow limitation. This occur due to remodeling of the airways.

• Asthma with obesity: obese patients may have prominent respiratory symptoms

Most Common Symptoms

If someone has asthma his airways become swollen and the muscles around the airways can tighten due to inflammation of the airways.

This swelling and tightening of muscles around the airways lead to difficulty for air to move in and out of the lungs, causing classical symptoms.

These includes

• Coughing,
• Wheezing,
• Shortness of breath and/or chest tightness.

Symptoms are often worse at night or in the early morning times and during walking. Symptoms are often triggered by allergens, cold air, viral infections , exercise, laughter.

Diagnosis of Asthma

The diagnosis is based on clinical symptoms and lung function test. Spirometry is an objective and reproducible test to determine the lung function. In this test the patient need to take a deep breath and then suddenly blow into a sensor to measure the amount of air in the lungs can hold and the speed of the air you inhale or exhale. The diagnosis can be made by demonstrating the presence of reversible airway obstruction. This test diagnoses asthma along with severity. Repeat test can be done to see the treatment response.

Management

Till date there is no cure for this condition. But the symptoms can be controlled with proper management. The management include education and learning to avoid triggers. Medications include Reliever and controller medication.

Reliever / Rescue medications-

These medications are those which quickly relax airways and thereby relieve the  symptoms. These include: short-acting beta-agonists (SABA) medication like salbutamol or levosalbutamol. They can be used as and when required basis.

Controller medications-

They reduce airway inflammation, control symptoms, reduced exacerations  and improve the lung function. These include inhaled corticosteroids (ICS) like

• Budesonide,
• Fluticasone,
• Mometasone
• Beclomethasone etc.

Combination Therapy-

Combined inhalers contain an inhaled corticosteroid and a long-acting beta-agonist (LABA) medicine. Combination medications include

• Fluticasone and Salmeterol,
• Budesonide and Formoterol,
• Mometasone and Formoterol.

Other medication include-

Anticholinergics medications  like tiotropium.

Leukotriene modifiers like montelukast, zafirlukast.

Oral and intravenous corticosteroids like prednisone and methylprednisolone, used in acute exacerbation.

Monoclnal antibody– Anti IgE Antibody- omalizumab. Helpful in allergic phenotype.

Advantage of MDI

Advantage of MDIs include:

• It is portable and compact. Anyone can carry easily.
• Efficient drug delivery.
• Short treatment time