Allergic Asthma

At present, around 5% of adults and 10% of children have clinically significant asthma in many countries, including the UK. Asthma has become one of the most significant chronic disorders in the developed world. Its prevalence has increased significantly within the last 25 years and it now affects around 300 million people worldwide.

Asthma is 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 this approach is having a strategy for allergen avoidance. According to Asthma UK, 5.4 million people in the UK have asthma, which includes 1.1 million children. The condition costs the NHS £1 billion a year and accounts for an annual 1.1 million lost working days and around 80,000 hospital admissions.

Yes, there are two main types of asthma – childhood onset (sometimes called extrinsic) and adult onset (or intrinsic). Most asthma does begin in childhood and is often associated with other atopic diseases like eczema and rhinitis.

1. Childhood-onset asthma often has clearly identifiable triggers which will bring on an attack. The link between the three allergic diseases in childhood is often called ‘the march of asthma’, describing the journey from, for instance, eczema in babyhood to asthma and rhinitis when a child reaches school age.

2. 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 many subcategories of asthma, such as:

Nocturnal asthma: Many people with asthma are woken at night with an attack. This feature is often associated with poor overall control of the disease.

Occupational asthma: Officially recognised as an industrial disease, occupational asthma is caused by exposure to a substance in the workplace. The UK Health and Safety Executive lists around 50 such substances which can be inhaled, some of them include chemicals such as isocyanates, aluminium and hair spray ingredients, various kinds of dust like flour and wood dust and animal dander all contribute to this type of asthma.

Brittle asthma: This is a severe form of asthma. In type 1 brittle asthma, the disease is uncontrolled and marked by very variable peak flow in the air to the lungs. In type 2 brittle asthma, there are sudden severe deteriorations from a stable baseline airflow from the lungs.

Exercise-induced asthma: Physical activity is a common asthma trigger, particularly in children.

Aspirin-sensitive asthma: Asthma that is brought on by aspirin and related drugs, such as anti-inflammatory drugs like ibuprofen. Asthma may also be brought on by beta-blockers, a common type of drug for treatment of high blood pressure.

Asthma can be particularly dangerous during pregnancy, please click here for more information on allergy & asthma during pregnancy.

Asthma does tend to run in families. However, asthma is not a single-gene disorder, with a clear pattern of inheritance. Instead, there are several ‘susceptibility’ genes involved in asthma, each contributing to the risk of developing the disease. So far, five potential susceptibility genes for asthma have been identified.

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 tests, blood tests, or scans, which can definitely diagnose asthma and distinguish it from other lung conditions. However, if asthma is suspected, you may be sent for breathing tests to confirm the diagnosis. These include:

Spirometry: This is breathing into a machine called a spirometer, which measures how much air you can breathe out, showing 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 to monitor your asthma.

Skin prick, or blood tests, may be carried out to find out what allergens are triggering your asthma.

Asthma tends to be a chronic disease. However, around 50% of children do ‘outgrow’ asthma by the time they become teenagers. But their asthma often re-emerges when they are older. Like other chronic diseases, such as diabetes, asthma is not curable in the same way as, say, pneumonia, but it can be managed successfully so you can still live a full life. To find out more, please visit ourasthma treatment information page.

Asthma can easily be mistaken for other conditions. Most commonly, asthma can resemble Chronic Obstructive Pulmonary Disease but there are some important differences. Chronic Obstructive Pulmonary Disease tends to affect those over 35, there is no link with family history, the patient is usually a current smoker, and breathlessness is progressive rather than intermittent.

Other disorders which might be mistaken for asthma, because of similarity in symptoms, include:

• Hyperventilation/panic attack
• Heart failure
• Cough induced by ACE inhibitors (a blood pressure drug)
• Vocal cord problems
• Cystic fibrosis
• Bronchiectasis
• Pulmonary thromboembolism (blood clot on the lungs)
• Lung cancer