A Unique Child: A doctor's diary ... Childhood asthma

Wheeze in children is a common presentation in general practice and it is up to the doctor to establish the cause of the wheeze, treat the child and educate the parents.

A wheeze is a whistling noise with a musical quality that is generated when the muscles surrounding the small airways of the lungs contract, causing narrowing of the airways and difficulty in breathing in, often referred to by doctors as 'tight airways'. This may be mimicked by trying to breathe through a narrow straw. It is also difficult to breathe out, taking longer for the air from the lungs to be expelled. Wheeze is heard on expiration, whereas noises on breathing in are described in medical terms as stridor.

The diagnosis of asthma in children is often based on a doctor's opinion and a child's response to treatment rather than tests.

CONDITIONS

While many people use the term wheeze and asthma synonymously, there are in fact a number of other conditions that may also cause wheeze. Arguably the most common of these is the common cold, described by doctors as 'viral-induced wheeze'. In this case, the child tends to become wheezy when they have a cold, but otherwise doesn't display features of asthma. Other causes of wheeze include allergy, inhalation of a small object, certain medications and some heart conditions.

Asthma is one of the atopic family of conditions, the others including eczema and hay-fever. Patients with one of these conditions are at higher risk of having another atopic disease, and they also run in families.

Except for wheeze, features suggestive of asthma include cough and breathlessness. Symptoms tend to be worse at night and are exacerbated by exercise, cold weather, damp, stress, allergy, infection, passive smoking and drugs such as ibuprofen.

SYMPTOMS

Some patients will present to a doctor with an 'asthma attack' in which the airways are very 'tight' and the child is struggling to breathe. An asthma attack is a medical emergency. In this scenario, the breathing rate increases, sometimes dramatically, the pulse rate rises and, given the child has to breathe harder to overcome the narrow airways, the skin between and beneath the ribs appears to suck in, known as 'recession'.

Having an asthma attack is very tiring; young children initially work hard to breathe during an attack, being too breathless to feed or talk. Left untreated, however, the child will eventually become fatigued and develop acute respiratory failure and even death. If the airways are very tight, the child may fail to inspire any oxygen at all, which again will lead to death unless the child is treated quickly.

TREATMENT

There are a number of important non-drug related measures that may significantly reduce the risk of developing asthma or the severity of the disease once it has been diagnosed.

Breastfeeding has been shown to be protective against asthma, whereas the evidence regarding other dietary measures is unclear. Avoidance of air pollution, cigarette smoke and house dust mite are all useful in reducing the severity of asthma. There is no good medical evidence that ionisers or homeopathy will help.

Drugs are of considerable benefit in asthma. 'Controlled' asthma is achieved when there are no symptoms in the day or night, the disease does not prevent a child from doing what they want to do, and 'rescue' medications are not required. The rescue inhaler, often called the 'blue' inhaler, contains a drug that opens up narrowed airways.

In some patients with very mild asthma, a rescue inhaler is all that is required. In others, a 'preventer' inhaler containing steroid, often referred to as the 'brown' inhaler, is required to reduce the inflammation in the airways and keep them open.

If the preventer dose is appropriate, and it is used every day, the need to use the rescue inhaler is kept to a minimum. Inhalers should be used through a spacer device, which ensures the drug is delivered to the airways rather than getting caught in the throat.

Other inhalers and drugs are also available for asthmatics who aren't controlled on standard preventer and rescue inhalers. Ten puffs of the blue rescue inhaler may be given via a spacer device as an interim measure in those suffering an asthma attack.

Asthma is a complex disease, which, if severe, can lead to breathing difficulties or even death. Any child with wheeze should be referred to a doctor for further assessment, and a child who is found to be breathless should always be considered to be at high risk and immediate medical attention should be sought.

Dr Raj Thakkar BSc(Hons) MBBS MRCGP MRCP(UK) is a full-time GP in Buckinghamshire