Asthma
About 5.1 million people in the UK have asthma. Asthma can affect anyone, at any age, anywhere. However, there is no need for asthma to stop a person living a full and enjoyable life.
What is asthma?
Asthma affects the small airways (bronchioles) carrying air in and out of the lungs. Airways can become inflamed, swollen and constricted (or narrowed) with excess mucus production.
A person experiencing an asthma attack may have symptoms of tightness in the chest, a wheezing or whistling noise in the chest, coughing and difficulty breathing.
An attack can occur suddenly. However, many people with asthma learn to recognise the warning symptoms - such as an itchy nose or itchy skin, dizziness or light-headedness, or an irritating cough.
Learning these signs can often alert a sufferer in time to take preventive action.
Asthma is a chronic condition, which means attacks will occur over a long period of time. Although there are times when acute episodes strike asthmatics, most people can say there are long periods during which they suffer few, if any, symptoms.
Main symptoms
The main symptoms of asthma are:
* Coughing
* Wheezing
* Shortness of breath
* A tight feeling in the chest.
It's becoming more common in the developed world and is now the most common chronic condition in the west. Aspects of our modern environment such as air pollution, processed foods, and centrally heated, double-glazed houses (an ideal breeding grounds for house dust mites) are thought to be contributing factors.
What causes asthma?
Asthma has many causes. It is still unclear exactly what these are. You may have oversensitive airways, a family history of asthma or be allergic to one or many asthma triggers.
One of the most common predisposing factors for asthma are allergies to house dust mites, mould spores, petrs and pollen, and sometimes food allergies. Most people find there are several things that can trigger their asthma.
Asthma has a tendency to affect families that are prone to allergies. Belonging to a family where some members have asthma and others have other allergies , such as eczema, hayfever or allergic rhinitis , makes a person more allergy-prone. However, because there are so many factors involved, it can be difficult to predict exactly who in a family will develop asthma.
Although asthmatic and allergic tendencies are inherited, there is no single gene involved. Rather, there are a number of different ones which react with factors in your environment to trigger the onset of asthma. Scientists are searching for the genes involved in asthma and this may eventually lead to a cure.
Environmental factors
Environmental factors that increase the risk of developing asthma include:
* Exposure to allergens during pregnancy (eg from foods in the mother's diet) which sensitise the unborn baby's immune system;
* Infections such as colds during early life;
* Being brought up in a house where there is a pet (especially a cat);
* Being introduced to certain foods such as cow's milk and eggs at a young age;
* Being born at a time of year when the pollen count was high;
* Being exposed to cigarette smoke in the uterus or early life - babies whose mothers smoke are twice as likely to develop asthma.
Main treatments
Today's asthma treatments are very safe and effective. Your doctor will work closely with you to devise a treatment plan that is suitable for you.
There are two main treatments for asthma – treatments to prevent and treatments to relieve an attack. These are delivered in inhalers of different types that let you breathe the medicine in through your mouth, directly into your lungs. The use of a spacer device increases the medication delivered to the lungs.
Preventers
Preventers are designed to quell swelling and inflammation in the airways and reduce mucus. This also reduces the sensitivity of the airways and so minimises potential damage.
The protective effect is built up gradually over a period of about a fortnight. Your medication must be taken daily to maintain protection, even if you are not experiencing symptoms. Most preventers are based on corticosteroids, usually known as steroids. These are completely different from the anabolic steroids sometimes used by bodybuilders and athletes.
Most common types of preventer are inhaled steroids. These can include beclomethasone, budesonide, fluticasone. There are other non-steroid preventers, usually used for children, such as sodium cromoglycate and nedocromil sodium. They are usually taken three to four times a day and are not generally as effective as steroids.
Many people worry about the side effects of steroids. High doses of steroids taken over a long period can have significant side effects. For this reason, doctors will be careful to prescribe the lowest possible dose needed to control your asthma.
Potential side effects of preventers
The main side effects are hoarseness and an increased risk of mouth and throat infections caused by thrush, a yeast that lives normally on the body's mucus membranes. Using the inhaler before brushing your teeth and rinsing your mouth out afterwards helps to avoid this. Using a 'spacer' makes it easier to inhale the drug, and so helps reduce the risks of steroids being absorbed into your body.
Relievers
Relievers are drugs that relax and open up the airways - medically known as bronchodilators - making it easier to breath. These are prescribed for the relief of asthma symptoms during an actual asthma attack, when peak flow readings are low and before exercise or activity to reduce the risk of an attack. Because these drugs do not reduce swelling and inflammation of airways, you may also need to take a preventer.
Some relievers alleviate symptoms almost instantly (rescue relievers). Others have a longer lasting action (long-lasting relievers). The latter may be prescribed if wheezing, breathing difficulties and coughing persist despite using preventer and a rescue reliever - or if symptoms come on in the night nocturnal asthma.
Common rescue relievers are salbutamol and terbutaline. Another type of reliever (most often prescribed for babies under two and for older people) called ipratropium bromide takes about 45 minutes to take effect.
Long-lasting relievers include oxitropium, salmeterol, and eformoterol, all of which are inhaled. Occasionally theophylline-based drugs are taken by mouth, so tablets may be prescribed.
Potential side effects of relievers
Side effects are usually mild and pass away quickly. The main ones are a slightly increased heartbeat, which may cause muscle trembling, especially in the hands. Some oral relievers may cause dry mouth, blurred vision, difficulties passing urine, or constipation. Theophylline-based drugs can occasionally cause nausea, more rapid heart rate, a nettle-like rash, dizziness, nervousness, headaches, irritability or restlessness. Always report any unusual symptoms to your doctor.
Most asthma treatments are inhaled. There are several different types of inhalers, but the main ones are aerosol-based called puffers and dry powder inhalers.
Puffers - the medication is mixed into a liquid and forced under pressure into a small aerosol canister. Once activated (usually by pushing down the canister), the liquid evaporates, leaving the active ingredient that you inhale. A measured dose of the drug is released every time the canister is pushed down. Both relievers and preventers can be given via a puffer.
Dry powder inhalers - the drug that comes in dry powder form is contained in a capsule. When the device is activated, the capsule breaks and the powder may be inhaled. In some inhalers the powder is contained inside a disk or compartment.
Spacers - because it can be hard to co-ordinate your breathing with an inhaler, you may be prescribed a spacer. This device allows more medication to enter your lungs than would be possible using inhaler alone. It's usually a large canister in two halves that click together with a mouthpiece at one end, and at the other, a hole that is attached to an aerosol spray. When you inhale, the drug is trapped in the space that is placed over the mouth - or the nose and mouth in the case of 'babyhalers.'
Nebulisers - a machine in which air or oxygen is forced through the liquid form of a drug, creating a mist, which is then inhaled through a mask or mouthpiece. It's used to administer high doses of reliever in an emergency and sometimes for children who are too young to use an inhaler.
Oral medication
There are a number of medicines that are taken in pill form, including leukotriene receptor antagonists and steroid tablets. Your doctor will be able to advise you when and why these may be necessary for you.
If your asthma is really bad, your doctor may also prescribe a short course of steroid tables to calm down your inflamed airways.
How to cope with an attack
Remove yourself from any conditions or situations that trigger your asthma. Treatment is not as effective in the presence of trigger.
Take a couple of puffs of your reliever, using a spacer if you have one. Stay calm and relaxed and breathe slowly to reduce fatigue.
Rest sitting up. It's harder to breathe lying down. Rest your hands on your knees to help support your back.
Wait 5-10 minutes to see if the attack eases. Measure your peak flow to see if your reading is improving. If it does, you can resume what you were doing. If the reliever has not taken effect within 15 minutes, call a doctor or ambulance. Carry on using the reliever until help arrives.
Never put off seeking medical help because of fear of making a fuss.
Hospitalisation
If you do need hospitalisation, take your medication (and your asthma management plan, if you have one) with you. The doctor will need to know what steroids you have taken, whether you used a nebuliser, and if you are taking the drug theophylline.
On arrival, the doctor will examine you and check your pulse, blood pressure and peak flow. You may also have a test to check blood levels of oxygen and carbon dioxide.
Treatment will usually begin with a nebuliser to improve peak flow reading. If you have to be admitted, a chest x-ray may be done to check for damage to your lungs. On the ward, you'll probably have nebulised bronchodilator treatment and steroid injections. Oxygen may be needed and, in severe cases, artificial ventilation.
Helping someone having an attack
If you're with someone who is having an asthma attack, try to stay calm. Make sure they take their reliever medicine. Listen to them, reassure them and encourage them to breathe slowly and deeply. If the person has a peak flow meter use this to monitor their condition.
Don't try to lie them down as this constricts the breathing passages. If the reliever has no effect after 10 minutes or if the peak flow meter falls to less than 50 per cent of the expected reading, you should call a doctor or ambulance immediately. You should also do this if the person becomes distressed or unable to speak properly.
Call for medical help immediately if:
* The person's symptoms worsen even after taking medication
* The peak flow number decreases or doesn't improve after treatment
* Breathing becomes increasingly difficult, for example, the person is struggling to breathe and the chest and neck are depressed with each breath
* The person has difficulty walking or talking and has to stop what they are doing
