Where is the problem
In asthmatics, the airways are inflamed and the inner wall of the airways is swollen. Therefore the space for passage of air is narrowed. The inflammation also causes accumulation of secretion within airways, further blocking flow of air. If one thinks of how the skin gets red and swollen after having an allergic reaction, the same happens within the air tubes of the lungs in asthmatics.
Why does asthma happen
Often asthma runs in families, therefore genetic factors can play a rope
Certain viruses (Respiratory syncytial virus, rhinovirus) can trigger asthma in mainly children and precipitate asthma attack in adults
Certain people are more allergic (sensitive) to certain substances than others. Inhalation of such substances can precipitate asthmatic symptoms. Common culprits are cockroaches, droppings from pet animals, house dust mites, grass pollen etc)
Sometimes certain chemicals precipitate asthma attack in some people in their workplace and this is called “occupational asthma”. These people are worse with their symptoms in their workplace than outside.
Hygiene hypothesis: There is a strong theory that cleaner/ more urban upbringing is causing more asthma in today’s children. There is far less number of asthmatics in children brought up in farms. This is because they have been exposed various substances from animals and hays etc from early life and their body systems get used to those substances and therefore do not become allergic.
In a large group of people, the first asthma symptoms occur in middle age and it appears that their body gets intrinsically reactive and airways get harmed in the process.
Exercise induced asthma: In a group of patients, exercise precipitate attacks of asthma
Obesity: In overweight people there are some chemical in excess in the body that has been shown to cause asthmatic symtoms.
What are the symptoms
The symptoms of asthma are as follows
The main symptom of asthma is wheeze
Tightness of chest
In a group of people, dry irritating cough is the only symptom of asthma
Symptoms of asthma often get worse in the late night/ early morning
What are the treatments
A single strategy is not enough for controlling asthma and the following are the pillars of asthma management
Regular monitoring of severity: As diabetics should monitor their blood glucose levels routinely at home, asthmatics also should monitor how good or bad their disease is by doing regular “peak flow” measurement at home and keeping an eye on their symptoms.
If someone with asthma is getting more breathless than usual -- waking up in the night with wheeze or cough, is using the relieving inhaler more than twice a week or if the peak flow values are consistently lower than normal – it should be noted that the disease is not under control and escalation of treatment should be done to prevent further worsening of symptoms.
Asthma action plan is now widely used tool that is used by patients to take control of their disease.
Patient educationKnowing how the disease is behaving helps the patient to take appropriate steps. Educating patients should involve informing them about specific asthma trigger and how to avoid them and also the role of different inhaled therapy and other form of treatment. Educating patients is integral part of asthma management.
Avoidance of trigger
Patients would usually know what usually triggers symptoms and should try to avoid them
Smoking, air pollution should be avoided
Various cleaning agents and their fumes can trigger asthma symptoms and should be avoided
Some patients are allergic to pet animals and should stay away from them
House and the bedding should be cleaned regularly. One has to be careful to keep the house free from cockroaches, mould, mice etc.
Patients should be careful in the winter months and should take influenza vaccination
Dietary triggers should also be avoided depending what triggered symptoms in the past (usual culprits are wine, some dried fruit, shrimp etc)
Medications – Aspirin and anti-inflammatory medications can make asthma worse and should be avoided.
Acid reflux- Gastro-oesophageal acid reflux can make asthma worse and should be actively treated.
Drugs and inhalers (pharmacological management). Drugs are divided in 2 groups
Preventers This group of drugs reduce inflammation in the airways and therefore prevents progression of the permanent damage to airway wall. For obvious reasons, they need to be taken regularly. Usually this is in the form of steroid inhalers. In severe disease, steroid tables need to be taken.
Relievers These are group of drugs that minimise the symptoms of after an asthma attack/ worsening of symptoms has taken place. Therefore they do not play a role in preventing long term consequences of asthma. They are usually in the form of inhalers but oral preparations are available as well.
How do the treatments work
There are 2 main groups of drugs as described – preventers and relievers.
Preventers are mainly different forms of steroids. Broadly this can be in inhaled form or in oral form. In either form, steroids reduce the inflammation in the wall of the air tubes – therefore keep the disease under control.In inhaled form the drug particles are directly delivered to the airways – therefore reducing the chance of side effects throughout the body.
However, during worsening of symptoms or during sever attacks, oral forms of steroids need to be taken to regain control of the disease process. This also reduces the chance of permanent damage to the airways. Oral forms can then be stopped when symptoms are back under control. Mostly this takes 1-3 weeks.
An important thing to note is that body does not get used to steroids in the inhaled form or when someone takes steroids for less than 3 weeks in oral form. It causes more harm not to use them when they are needed, as airways start to get permanently damaged.
If the disease is so difficult that the patient had to take oral steroid for more than 3 weeks, then the dose should be gradually reduced instead of being suddenly stopped.
When the muscles of the air tubes become constricted or tight, the diameter of the airways become narrow and it is then difficult to breath. The reliever group of drugs relax these muscles– thereby they prevent the narrowing of the diameter of air tubes. Once used in inhaled form, they take usually less than 5 minutes to act.
There are 2 broad forms of this group of drugs in terms of how long they last in the body - short acting and long acting.
Short acting : Salbutamol and Ipratropium belong to this group. These drugs are to be taken to relieve immediate symptoms, when the patient is wheezy or tight chested.
Long acting: Salmeterol, Formeterol, Aclidinium, Indacaterol belong to this group. In patients, who need to use their short acting relievers frequently, it is best to switch to a long acting version so that they don’t have to use their inhalers too frequently.**
** One must remember, however, that a doctor needs to assess why the patient needs to use the short acting ones so frequently and consider increasing the steroid inhaler/ Use short oral steroid course as this is the treatment which is going to keep the disease under check.
It is important that someone with asthma should seek immediate medical help if the breathing/ wheezing is getting progressive worse as in some people, it could deteriorate fast and can be fatal. Hospitalisation, oxygen, reliever medication given through devices called nebuliser and steroid are the treatments that these patients need. A very small proportion of these patients need admission to intensive care for artificial support for their breathing.
What is the prognosis
Around half of children grow out of asthma beyond their teens.An early onset asthma, that persists, will cause some deficits in lung function later in life compared to someone who never had asthma.
In adults, unlike children, asthma hardly ever goes away completely and most people with asthma would be fully functional. It also is not usually known to reduce one’s life span in a usual asthmatic, unless someone suffers from a sever asthma attack requiring hospital admission.
In adult asthmatics, only about 5% reports disease progression and in the rest, the disease remains stable. In most people who are at least moderately symptomatic, the age related decline in lung function is faster than people who do not have asthma.