Attacks of breathlessness, coughing, and/or wheezing in children due to reversible narrowing of the airways
In children with asthma, the airways in the lungs tend to narrow temporarily. Narrowing occurs when the linings of the airways become swollen and inflamed and produce excess mucus, which may block the smaller airways.
Asthma affects about 1 in 11 children in the UK and is the most common long-term respiratory disease in children. The reason for the high prevalence of asthma in children is not known, but allergies and other environmental factors may be involved.
Asthma attacks in children are a common cause of absence from school and admission to hospital. However, between attacks, children can be perfectly well. Severe attacks of asthma are distressing for both children and their parents and can be life-threatening.
Asthma is more likely to develop in children with a family history of the condition, suggesting that a genetic factor may be involved. Other respiratory disorders, especially those associated with premature birth (see Problems of the premature baby), may also increase the risk of developing asthma. Regular exposure to cigarette smoke in the home and pollution from car exhaust and factory fumes may also be risk factors for asthma.
In children under the age of 5, attacks of asthma are usually triggered by a viral infection, such as the common cold. In older children, asthma attacks are often caused by an allergic reaction to substances such as pollens, moulds, house dust mites, and the fur or dander from animals. Exercise, especially outside in cold, dry conditions, may also trigger an asthma attack. In rare cases, certain foods, such as milk, nuts, and eggs, can provoke asthma. In some affected children, emotional stress may make the attacks more severe.
Symptoms vary in severity from day to day and week to week and with the age of the child. They appear rapidly and may persist for a few hours or longer. Symptoms may include:
Shortness of breath.
Tightness in the chest.
Dry cough that may be worse at night and disturb sleep.
Very young children with asthma often have a dry cough at night and no other symptoms. Older children often feel tired due to disturbed sleep and may have difficulty participating in strenuous sports due to shortness of breath. Children with asthma are also predisposed to the allergic disorders eczema (see Eczema in children) and hay fever (see Allergic rhinitis).
A severe asthma attack may cause very rapid breathing, difficulty speaking, and indrawing of the chest wall. If the level of oxygen in the blood is low, a child may develop a bluish tinge to the lips and tongue, a condition known as cyanosis. You should call an ambulance immediately if your child has such an attack, because he or she needs emergency treatment.
Left untreated, severe asthma may impair a child’s growth (see Growth disorders) and development. Because children who have asthma often have difficulty sleeping, many become chronically tired, which can lead to poor performance at school.
Diagnosis of the condition is based on a description of your child’s symptoms. The doctor will listen to your child’s chest with a stethoscope. An older child may be asked to breathe out through a peak flow meter, a special device that measures the child’s capacity to exhale (see Monitoring your asthma). To confirm the diagnosis, the doctor may prescribe a trial of a quick-relief drug that opens up the airways in the lungs (see Bronchodilator drugs). If your child’s symptoms are caused by asthma, they should improve significantly after administration of the drug.
Once the diagnosis has been confirmed, your child may have a skin test to look for specific allergies that may be the trigger factors for his or her asthma attacks (see Skin prick test).
The aim of treatment for asthma is to enable your child to live as active a life as possible with a minimum of drug treatment. The doctor may give you a detailed plan for managing your child’s asthma with advice on when to change treatments and what to do if your child has a sudden attack. It is important that children who have asthma understand their condition and are confident about dealing with their symptoms. Some children will need to take regular peak flow readings at home to monitor their asthma over a period of time. Since the normal peak flow values are determined according to a child’s height, growth should also be measured regularly.
There are many ways in which you can modify your child’s environment to minimize contact with factors that may trigger an attack (see Reducing the risk of asthma attacks in children).
The drugs that are used to treat children with asthma fall into two groups: reliever drugs and preventer drugs, which are usually corticosteroids (see Corticosteroids for respiratory disease) although sodium cromoglicate and leukotriene antagonists (see Antiallergy drugs) may also be used. The reliever drugs act rapidly to open up the airways and relieve wheezing. They usually work within 10 minutes, but their effect lasts for only a few hours. Children who have mild asthma attacks once or twice a week may be prescribed a reliever drug for use when symptoms occur.
Children who have frequent asthma attacks also need to take regular doses of preventer drugs. These drugs take effect slowly over several days and should be taken regularly, even if there are no symptoms of asthma. Preventer drugs reduce inflammation of the airways and prevent the symptoms from occurring. Respiratory corticosteroids are commonly prescribed as preventer drugs, but other drugs, such as sodium cromoglicate, may be given to dampen the allergic response and help to keep the airways open. Leukotriene antagonists may be used in addition to inhaled corticosteroids to treat moderately severe asthma.
Drugs to treat asthma are usually administered with an inhaler. A spacer device attached to an inhaler may be necessary for young children who find an inhaler difficult to use effectively (see Giving inhaled drugs to children). A nebulizer, a device that delivers a drug in aerosol form through a face mask, may be used during a severe asthma attack. It is crucial to learn the correct technique for using inhalers and nebulizers. The doctor or a nurse will show you and your child how to use the devices properly. After a severe asthma attack, oral corticosteroids may be prescribed for your child in addition to the inhaled drugs.
You or your child should always carry a reliever inhaler in case it is needed to treat an asthma attack. An inhaler should also be kept at your child’s school and you should ensure that his or her teachers understand its use. If your child’s symptoms are not eased by a single dose of a reliever drug, a repeat dose should be taken. If that fails to improve the symptoms, call for an ambulance immediately or take your child to the nearest accident and emergency department. It is important to remain calm and reassure your child. Once in hospital, your child will probably be given oxygen and high doses of reliever drugs through a spacer or with a nebulizer to relieve the symptoms. He or she may need to stay in hospital to recover completely from a severe attack of asthma and may also require a course of oral corticosteroids.
Children with asthma are usually able to lead active lives through careful use of drugs and avoidance of trigger factors, such as animal fur. About half of all children with asthma grow out of the condition by the time they are teenagers. Asthma that persists past the age of 14 is likely to continue into adulthood (see Asthma).
Despite the ease with which asthma can be controlled, severe attacks of asthma can cause death. In most cases, fatalities are caused by a delay in getting an affected child to hospital and a lack of understanding about potentially life-threatening symptoms.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.