Asthma has become one of the most common chronic disorders in the developed world. Asthma is difficult to describe, but the International Consensus Report on the Diagnosis and Management of Asthma defines it the following way: “Asthma is a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role".
Throughout the developed world, typically 5% of adults and 10% of children have clinically significant asthma. Its prevalence has increased significantly over the last 25 years and is now thought to affect around 300 million people worldwide.
Asthma can be a serious condition, which occasionally proves fatal, accounting for 1,131 deaths in the UK in 2009. However, most deaths and hospital admissions for asthma are preventable. Asthma is a condition that can be managed successfully and part of that management should include a strategy for allergen avoidance.
For example, in the UK, around 5.4 million people suffer from asthma, which includes 1.1 million children. The condition costs health services around £1 billion a year and accounts for an annual 1.1 million lost working days and around 80,000 hospital admissions.
Asthma comes in several forms
There are two primary types of asthma – childhood onset and adult onset. Most asthma does begin in childhood and is often associated with other related conditions like eczema and rhinitis.
Childhood onset asthma often has clearly identifiable triggers which will bring on an attack.
Adult onset asthma may be a continuation of childhood onset asthma, or it may be a new onset of the condition. Asthma can occur at any age, and should be considered in anyone who has a chronic cough. In adult onset asthma, there is often no obvious trigger, except for a chest infection.
There are also several sub-categories of asthma, including:
It can run in families
Asthma tends to run in families. However, asthma is not a single-gene disorder, with a clear line of inheritance. There are several ‘susceptibility’ genes involved in asthma, each contributing to the risk of developing the disease.
Diagnosis depends upon the doctor taking a careful medical history from the patient and noting whether the hallmark symptoms of wheeze, chest tightness, breathlessness, and cough are present. There are no laboratory or other tests which can definitely diagnose asthma and distinguish it from other lung conditions. However, if your doctor suspects asthma you may be subject to breathing tests to help confirm the diagnosis. Such tests include:
Spirometry: Spirometry is breathing into a machine which measures how much air you can exhale, which shows whether the airways are obstructed or not.
Peak expiratory flow rate test: A small hand-held device, called a peak flow meter, is used to measure how fast you can blow air out of your lungs in one breath. The peak flow meter can be a useful tool to use yourself at home to monitor your asthma.
Skin prick, or blood tests, are often carried out to find out which allergens might be triggering your asthma.
Thorough diagnosis by a doctor is a must, as asthma can easily be mistaken for other conditions, including:
Asthma tends to be a chronic disease (that is once you have asthma it will remain with you for the rest of your life). However, around a half of children do ‘grow out of’ asthma by the time they become teenagers, sometimes to re-emerge in adulthood. Like other chronic diseases, such as diabetes, asthma is not curable in the same way that, say, an infection can be cured. However, asthma can be controlled successfully so you can still live a full life.