Allergic Asthma and Wheeze

Asthma is a common condition, which affects one in ten children and one in twenty adults. Although asthma usually begins in childhood, and half of those affected will outgrow it by adolescence, it can also occur at any age. There often an allergic background and a tendency for asthma to run in families, as do related conditions such as eczema and hayfever. Adult onset asthma usually doesn't have an allergic basis, but may be associated with aspirin sensitivity. Asthma cannot be cured but it can be kept under control so that those affected can live normally and enjoy involvement in sport and other activities. Most asthma sufferers are actually allergic to certain environmental agents such as cats, dogs, housedust mites, pollens and mould spores.

What happens in asthma

The typical symptoms of asthma include wheezing, a dry troublesome cough, tightness of the chest and shortness of breath. This is due to narrowing of the air tubes in the lungs - brought on by tightening of the muscles surrounding the airway, inflammation and swelling of the airway lining and production of thick sticky mucous within the airway. This process is usually triggered by a specific allergy or when something irritates the lungs. Daily variation in Peak Expiratory Air-flow of 15% or more confirms the presence of asthma. This diurnal variation is referred to as Peak Flow (PEF) Variability. Lowest PEF readings are typically seen in the early morning and highest PEF readings in the evening. 

We refer to asthma symptoms that occur occasionally (less than twice a week) and which respond promptly to reliever medication as mild or Intermittent asthma.  When asthma becomes more problematic and symptoms occur more often than 2 times per week, with night-time exacerbations; this is then called Persistent asthma and depending on severity would be grade as mild persistent, moderate persistent or severe persistent (where symptoms occur daily and are difficult to control with conventional preventer and reliever treatments).

Things that worsen asthma

Asthma attacks are often triggered by allergies to housedust mites, grass and tree pollens, furry animals, birds, some foods and mould spores.

A cold or flu can make asthma worse and this effect may persist for up to six weeks unless treatment is adjusted.

Pollutants in the environment such as cigarette smoke, certain chemicals and car exhaust fumes can trigger an attack.

Exercise, especially in cold weather, can cause an asthma attack but with correct treatment exercise-induced asthma can be well controlled.  Asthmatics should not avoid sport or exercise as in the long-term they are beneficial and increase lung fitness.

Emotion - anger, anxiety and laughter can all trigger an attack. However, it is not true that "nerves" are the cause of asthma.

Drinks containing Sulphur Dioxide can trigger asthma attacks.

Medication such as aspirin, some anti-inflammatory tablets as well as "Beta Blocker" blood pressure tablets and eye-drops for glaucoma may aggravate asthma in adult life.

Modern Asthma Treatment.

Asthma cannot be cured but with the right treatment most asthma sufferers can lead completely normal lives. There are two types of treatment: PREVENTER and RELIEVER medication. These are usually given in an atomised form via inhaler devices. We tend to recommend the additional use of a plastic SPACER to increase penetration of the medication deep into the lungs.

It is important to undergo allergy tests to identify which environmental allergens trigger the asthma. This is done by Skin Prick Tests or RAST tests on a blood sample, testing for specific antibodies (IgE) to housedust mites, cats, dogs, pollens, mould spores and cockroaches. Once the specific allergy is identified, avoidance of the allergen may help control symptoms.

Preventer medicines include Sodium Chromoglycate (Intal, Cromogen), Nedocromil Sodium (Tilade) and low dose inhaled cortico-steroids Beclomethasone (Becotide, Qvar, Asmabec), Fluticasone (Flixotide) and Budesonide (Pulmicort) . All of these medicines are very safe to use at the recommended dosages and SHOULD BE USED CONTINUOUSLY EVEN WHEN SYMPTOM FREE.

Newer oral preparations called Leukotriene Antagonists are available and include Montelukast (Singulair) and Zafirlukast (Accolate). Monoclonal anti-IgE antibodies in the form of Omalizumab (Xolair) may have a profound effect on severe allergic asthma, this treatment is not readily available and is extremely expensive to administer.

As better treatments have evolved, older oral tablets such as the Theophyllines and Aminophylline are rarely prescribed these days.

Combination Preventer and Reliever medications are Seretide and Symbicort. Seretide, which is a combination of Salmeterol and Fluticasone have a synergistic or additive effect in asthma control and treatment. Symbicort is another new combination preventer and controller inhaler which contains Budesonide and Eformoterol.

There is no direct connection between the effects of reliever and preventer medicines. They have quite separate actions on the lung airways.

Complementary treatments are often incorrectly called "alternative" treatments; there are no effective alternatives to modern medication in asthma treatment. Homeopathy, Buteyko and breathing exercises are not as good as conventional treatment. If you decide to consult someone other than your doctor, remember to continue using your preventer and reliever medicines.

Keeping Asthma Controlled

It is very important to recognise when asthma is getting worse.

Asthma that gets worse at night or in the early hours of the morning indicates a need for additional treatment. Wheezing or a tight chest that is not relieved by several reliever inhalations, particularly if there is difficulty with talking, necessitates urgent medical assistance.

Those asthmatics that are often troubled with asthma attacks should have their own PEAK FLOW METER at home so that they can measure their lung performance and know when extra treatment or medical advice is necessary. Discuss an Asthma Management Plan with your doctor - you may need a short course of oral Steroid tablets at home to take in an emergency.

Your doctor or Practice Nurse will develop a STEPWISE ASTHMA MANAGEMENT PLAN with you which will explain how to use the preventer and reliever medication and what to do if the asthma gets worse.

Chronic cough and clinical asthma variants

Various different types of asthma  have been identified over the years.

Classical asthma: Typically reversible wheezing and airways bronchospasm, associated with eosinophils in the mucous and which responds well to bronchodilators (salbutamol)  and inhaled steroids (beclomethasone).

Cough-variant asthma: (first described in 1972) This dry cough responds well to broncho-dilators (implying presence of  bronchospasm) and is associated with a very sensitive cough-reflex .  This is a common condition in  small children and  one third will progress to develop Classical asthma.

Eosinophilic bronchitis: An isolated chronic cough seen in adults and associated with eosinophils in sputum, but no airways bronchospasm or wheeze.  This condition may progress to fixed airway disease such as occurs in chronic bronchitis and emphysema. This cough does not respond to broncho-dilators but does improve with inhaled steroids.

Atopic cough: (recently identified asthma variant). This isolated chronic cough in children is not associated with airways bronchospasm or wheeze. There is usually a family history of allergy, and allergy skin tests are positive with raised IgE, however there are no eosinophils in the sputum. This cough responds well to antihistamines (cetirizine, loratidine or chlorpheniramine) and inhaled steroids but not at all to  bronchodilators (salbutamol).

Certain conditions such as Acute Bronchopulmonary Aspergillosis (a fungal infection and allergy in the air tubes) and Extrinsic Allergic Alveolitis (Farmer's Lung) should be considered if people with asthma like symptoms do not respond to standard asthma therapies.  Occupational asthma may occur in Bakers and also  fro exposure to isocyanates, wood dust, platinum salts and animal allergens (in veterinary workers)

Copyright Dr Adrian Morris 2006

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