All you need to know about Asthma



Bronchial asthma is a medical condition that is due to inflammation, swelling and narrowing of the smaller airways of the lung resulting in difficulty breathing. It is known to affect about 235 million people worldwide with an overall prevalence of about 3% in India which is approximately 20 million people.

People of any age group can be affected by asthma, however almost 50% of the cases develop before the age of 10 years. It also tends to occur more commonly in boys than girls in childhood but with increasing age(>40 years) it becomes more common in women than in men.

Causes and Risk factors

Asthma occurs as a result of hyper-responsiveness of the conducting zone of the lung (trachea, bronchi & bronchioles) due to multifactorial triggers and recruitment of cells of humoral and cell-mediated immunity like mast cells, basophils, eosinophils, T-helper cells and B cells. This hyper-responsiveness which is generally reversible results in inflammation of the airways associated with airflow obstruction, swelling and accumulation of thick mucus that result in cough, breathlessness or wheezing. Chronic asthma or repeated attacks of asthma can however lead to irreversible or partially reversible changes due to airway remodeling and smooth muscle proliferation.

The factors associated with a higher occurrence of asthma are young boys, older women, obesity, higher socioeconomic factors, history of atopic infection, family history increases the risk by three to six times, early age of motherhood, smoking in pregnancy increases the risk in the newborn, premature birth and low birth weight.

Triggers of Bronchial Asthma

There are various factors which may trigger the occurrence of an asthma attack or worsen symptoms in a person with a known history of asthma. These triggers may differ from person to person and may cause different levels of exacerbations. Some well-known triggers of asthma include.

  • Allergens like pollen, mold, pet dander or dust mites
  • Smoking or passive smoking
  • Infections like common cold, viral infections, pneumonia and sinusitis
  • Irritants like environmental pollutants, fragrances or chemicals with strong odour
  • Change in weather particularly exposure to cold, dry air
  • Exercise
  • Stress, anxiety or other strong emotions
  • Certain food and food additives like monosodium glutamate, egg, shellfish etc
  • Gastroesophageal reflux disease or heartburn
  • Drugs like beta blockers, aspirin, ACE inhibitors or NSAIDS

    • Signs & Symptoms

    The symptoms observed in asthma can vary for each individual and depends on the severity of acute exacerbation. Generally, the most common symptoms seen are shortness of breath, frequent coughing particularly at night, sleep disturbance, chest tightness, wheezing or whistling sound on breathing out.

    Whereas a severe attack of asthma may present with abnormal rapid breathing, reduced oxygen levels, wheezing both during expiration and inspiration, loss of consciousness, reduced blood pressure, chest pain and bluish discoloration of the nails or lips due to lack of oxygen. Very rarely a severe asthma attack called status asthmaticus can lead to a silent chest where no wheezing is heard despite adequate treatment and is a medical emergency that may lead to cardiac or respiratory arrest requiring mechanical intubation and ventilation.

    Asthma in Pregnancy

    Though there is no direct causation between pregnancy and asthma, it is noticed that pregnancy can worsen the symptoms of asthma in an already known asthmatic patient. Therefore it is very important to adequately monitor and control asthma during pregnancy to maintain the well-being of both the mother and the child. The different medications safe in pregnancy are short-acting inhaled bronchodilators, leukotriene antagonists, and some inhaled or oral corticosteroids like budesonide and prednisolone.

    Inadequately controlled asthma during pregnancy is known t be associated with pregnancy-induced hypertension, preterm delivery, low birth weight, congenital malformations, and increased risk of fetal death or spontaneous abortions.

    Diagnosis

    Asthma can be evaluated through a complete medical history, physical examination, and a few basic tests like chest X-ray, spirometry to assess lung function, FeNO test that uses the levels of nitric oxide in your breath to denote the level of inflammation, peak expiratory flow rate and allergy testing. Other tests like the methacholine challenge test, sputum eosinophils, and provocative tests for exercise or cold-induced asthma are also done.

    Treatment

    The treatment for asthma mainly aims to reduce the number of asthma attacks, improve breathing and help increase the patient's participation in daily activities along with finding effective ways to reduce the side effects of long-term treatment. The different treatment options available are based on the classification of asthma based on severity. They are administered either as inhalers, nebulizers or as oral formulations.

  • Bronchodilators: they help relax the smooth muscles around the airways and relieve bronchospasm. They are hence use as the first-line treatment for acute exacerbations. Eg short-acting or long-acting beta-agonists.
  • Corticosteroids: which are anti-inflammatory medications that reduce the swelling and also reduce mucous production, thereby improving airflow.
  • Other anti-inflammatory agents used are mast cell stabilizers and leukotriene antagonists
  • Anticholinergic drugs like ipratropium and tiotropium work by inhibiting the airway constriction and secretion of excess mucus in the bronchi. They also dilate the airways in patients who have already been on beta-agonists or corticosteroids.
  • Methylxanthines like theophylline are drugs which have both anti-inflammatory and bronchodilator effects.
  • Immunomodulators are medications like antibodies, which act against certain molecules mediating airway inflammation in asthma. They are especially used in patients who have severe asthma attacks due to exposure to allergens.

    • Can Asthma be Cured?

    Although asthma cannot be cured, multidisciplinary approaches to treatment along with ways to prevent exacerbation have led to asthma becoming a very much treatable disease. The advances and available treatment protocols for asthma have become extremely effective that most people tend to lead a near normal life and have near complete control of their asthmatic symptoms.

    Patient education, identifying and avoiding triggers that cause an asthma attack and proper compliance to treatment can lead to a better quality of life and definitely helps reduce the frequency of asthma attacks.