Asthma

Asthma is a long term condition in which air passages in the lungs become narrow due to inflammation and contraction of the muscles around the small airways. This causes symptoms such as cough, wheezing, shortness of breath and chest tightness. These symptoms are intermittent and are often worse at night or during exercise.

Other names #

Asthma is also known as

• Obstructive airway disease

• Bronchial asthma

• Reactive airway disease

Causes Of Asthma #

The exact cause of asthma is still not known. It is also believed to be a multifactorial pathology that is affected by both genetics and environmental factors. Ideally, when your immune system comes in contact with an allergen, it triggers an immune response to fight against the allergen. But in people with asthma, this immune response is very strong which leads to inflammation. This in turn, causes the airways to swell and become narrowed causing it difficult to breathe.

During an asthma attack, three things can happen:

• Bronchospasm: The muscles around the airways constrict (tighten). When they tighten, it makes the airways narrow. Air cannot flow freely through constricted airways.

• Inflammation: The airway linings become swollen. Swollen airways don’t let as much air in or out of the lungs.

• Mucus production: During the attack, your body creates more mucus. This thick mucus clogs airways.

Symptoms of Asthma #

• Breathlessness (shortness of breath) when exposed to triggering factors

• Cyanosis (blue discolouration of face and extremities)

• Wheezing or whistling sound during breathing

• Chest tightness, which feels like a tightened band around the chest

• Intense coughing or the urge to cough that may be triggered by an allergen or other environmental factors

• Fatigue during and after an asthma attack

Risk factors #

• Genetics: Evidence suggests that presence of asthma and its severity can be influenced by the genome or genetic make up of a person.

• Air pollution: Exposure to outdoor pollutants like nitrogen dioxide and diesel particulates, is associated with increased asthma symptoms.

• Diet: Diets low in antioxidants such as Vitamin A, Vitamin C, Vitamin D, magnesium, & selenium and may also predispose to the development of asthma.

• Viral infections: Respiratory tract infections that may be caused by a virus during childhood can be a cause for asthma in adulthood.

• Allergens: Environmental allergens such as pollen dust or mites can trigger an asthma attack.

• Medications: Certain medicines such as aspirin & beta-blockers are also a cause of asthma attacks in certain individuals.

• Exercise: Exercise may aggravate asthma and make breathing difficult.

• Chronic sinusitis: Post-nasal drip caused by sinusitis can trigger coughing and itchy throat which can aggravate asthma symptoms.

• Insects or plants: Some people may be allergic to certain plants or insects that may act as a trigger for asthma.

• Obesity: Being overweight puts you at a higher risk of asthma and its symptoms such as shortness of breath and wheezing.

• Stress: Emotional factors such as stress can trigger not only anxiety but also asthma symptoms like breathlessness.

• Smoke: Smoke or chemical irritants such as fumes can also lead to asthma symptoms like wheezing and shortness of breath.

Diagnosis #

• Physical examination: During a physical examination, your doctor might look at your eyes, ears, nose or throat for swelling or drainage which may indicate allergic reaction. Also, checking your chest and lungs for wheezing or whistling sounds which may indicate inflammation and contraction of airways.

• Blood tests: Your doctor may recommend certain blood tests to check the level of inflammation, antibodies and eosinophils (a type of immune cells). These include complete blood count (CBC), immunoglobulin E (IgE) and absolute eosinophil count (AEC).

• Pulmonary function test: Pulmonary or lung function tests are done to find if there are any airway obstructions. In case there is clinical suspicion but the lung function test comes out to be normal, then other tests such as post-exercise test or allergen challenge test can help in determining bronchial hyperresponsiveness in adults.

• Chest X-ray: In severe cases, hyperinflation of lungs may be seen which can be detected with the help of chest x-ray.

• Allergy panel/asthma/rhinitis screening test: If you are showing symptoms of asthma and an allergic trigger is suspected, then allergy diagnosis is generally recommended. The diagnosis of an allergy consists of medical history, skin prick test, and specific IgE (immunoglobuline group E) test. ​

Prevention #

• Staying away from allergens such as animal dander, dust mites, mold, etc.

• If possible, wear a mask whenever you come in contact with smoke and other irritating fumes.

• Patients suffering from asthma should avoid exposure to viruses and other respiratory infections.

• It is important to wash your hands carefully. Don’t forget to get your flu and/or pneumonia vaccine every year and reduce the risks of an asthma attack.

• Maintain an asthma diary and note specific triggers so you can inform your doctor about these and reduce flare-ups in the future.

Treatment Of Asthma #

The common treatment approach for people with asthma involves use of preventive medicines (also known as controllers) and quick-relief medicines (also known as relievers)

Controllers #

These medicines help reduce the swelling of the airways and prevent mucus formation. They are mostly used to prevent asthma attacks and protect the lungs. These medicine classes are:

Corticosteroids #

These are the best and most commonly prescribed drugs for asthma. They act by inhibiting the activity of the inflammatory compounds such as prostaglandins, leukotrienes, and histamines which are responsible for inflammation. They are broadly classified into:

Inhaled corticosteroids (ICSs) #

ICSs are amongst the most effective anti-inflammatory medications available to treat asthma. Low-dose monotherapy of inhaled corticosteroids is usually given as first-line maintenance therapy for most children and adults dealing with asthma. Regular use of ICS have been shown to reduce symptoms and flare ups of asthma along with improvement in lung function. Example of drugs that belong to this category are:

• Beclomethasone

• Budesonide

• Fluticasone

Oral corticosteroids #

These are generally given for the acute treatment of moderate to severe asthma. Prolonged use of oral steroids are generally avoided as it has been associated with potentially serious side effects. Examples include:

• Prednisone

• Prednisolone

Leukotriene receptor antagonists #

These medicines are effective for the treatment of asthma, are well tolerated and are safe to use. As the name suggests, they work by blocking the action of an inflammation-causing chemical messenger called leukotriene. These medicines thereby reduce the inflammation in the airways, preventing asthma and relieving symptoms of allergies. Common examples of these medicines include:

• Montelukast

• Zafirlukast

Biological therapies #

Biological therapies such as the anti-IgE monoclonal antibody, example omalizumab, can reduce the frequency of asthma attacks. This drug is given subcutaneously once every 2–4 weeks. This medicine is specific to patients with difficult to control asthma with an elevated serum IgE level. It is also given to people whose asthma symptoms do not improve even with ICS therapy in combination with a second controller medication.

Relievers (bronchodilators) #

These are the preferred medications for the treatment and maintenance of acute symptoms of asthma and are generally prescribed to all patients with asthma. They work by dilating the bronchioles, thereby providing only temporary relief. These medicines are used to relieve the symptoms of asthma when they occur but not reverse the inflammation that has already occured. Drugs that belong to the class of bronchodilators are:

Short-acting beta agonists (SABA) #

These medicines are used for the treatment of asthma symptoms and its exacerbations. As the name suggests, these are known to provide quick relief. For example, salbutamol which is the common drug, has an action onset of under 5 minutes & lasts for 3 to 6 hours. Some of the common examples include:

• Salbutamol

• Terbutaline

• Levalbuterol

Long- acting beta agonists (LABA) #

This class of medicines contain low doses of controllers and relievers with a long lasting effect. These not only help you to relieve the symptoms but also protect you from asthma attacks. These medicines are often used in conjugation with other drugs such as corticosteroids. They have an action onset of more than 5 minutes but the effect lasts for at least 12 hours. Common example include:

• Salmeterol

• Formoterol

• Indacaterol

• Olodaterol

• Vilanterol

Methylxanthines #

These are a new class of medicines used for the treatment of asthma. It is known to aid in the treatment of asthma by reducing airways inflammation and airway obstruction which is seen in asthmatics. Theophylline is one of the most commonly prescribed methylxanthines.

Anticholinergic drugs #

This class of medicines work by blocking the action of acetylcholine, a neurotransmitter which plays a key role in controlling the constriction of smooth muscles and inflammation. These are further classified into:

Short acting muscarinic antagonists (SAMA) #

Ipratropium is the common medicine that belongs to this class. It is used to treat and prevent the symptoms of asthma and COPD along with improving the breathing.

Long acting muscarinic antagonists (LAMA) #

Tiotropium is the common medicine which is mainly used for the treatment of chronic obstructive pulmonary disease (COPD) and asthma.

Other therapies #

Bronchial thermoplasty is a bronchoscopic treatment using thermal energy to ablate airway smooth muscle in accessible bronchi. It may reduce exacerbations in patients not responding to maximal inhaler therapy.

Personal care #

• Stay away from allergens

You must know what could trigger asthma such as plants, dust or certain food items and keep them away from your home.

• Stay hydrated

Drinking plenty of water throughout the day keeps the mucus thinner, helps in better breath control and digestion, thereby keeping asthma in control.

• Keep the air filters clean

It is important to keep the air around you clean and for that you need to keep the air filters cleaned or changed to avoid triggers for asthma.

• Avoid strong fragrances

Not only dust, but strong fragrances such as cleaning sprays, perfumes & air fresheners can also trigger asthma. Therefore, it is best to avoid these sprays.

• Keep yourself active

It is commonly believed that exercise can trigger asthma attacks. However, if you are taking your medication regularly and indulge only in moderate exercise then you can easily stay active and fit.

• Avoid exposure to dust

Keep your surroundings clean to avoid build up of dust. Always wear a mask while cleaning or vacuuming.