Health: What causes wheezes in children?
Dear Mirror doctor, Please can you help explain what causes wheezes in children?
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Dear Umar, Wheezing is a whistling sound that occurs when smaller airways are narrowed. It is usually a high-pitched sound which can either be heard with the naked ears or sometimes with the help of a stethoscope.
It can be heard when breathing in (inspiration) or when breathing out (expiration). It can be caused by the presence of any of the following:
Bronchospasm- where the muscles around the windpipe and smaller airways go into spasm narrowing the lumen and causing the whistling sounds when air is blown into or out of it.
Swelling of the mucosal lining- the airways have cells lining them which can swell when exposed to certain things their bodies don't like or when injured. These could be perfumes, dusts, house mites and sometimes even certain foods.
Wheezing can also result from excessive amounts of secretions accumulated in the breathing tubes. The end result is that the lumen of these tubes are narrowed and a wheeze is heard.
An inhaled foreign body is an important cause of wheeze, especially when heard during inspiration.
Removal of the foreign body usually ameliorates the wheeze.
Wheezing is very common throughout childhood, except in the period soon after birth called the neonatal period, where it is relatively rare.
Some studies have reported a prevalence of wheeze, in preschool children, as high as 40 per cent.
Conditions that cause wheezing in children include
• Respiratory tract is usually caused by viruses.
• Asthma
• Bronchiolitis.
• Croup.
• Cigarette smoke or other forms of air pollution.
• Gastro-oesophageal reflux.
• Foreign body inhalation.
• Rare causes include an abnormal connection between the food pipe and wind pipe called tracheo-oesophageal fistula, certain chronic lung conditions such as bronchopulmonary dysplasia, heart failure and children born with heart diseases.
Wheezing in childhood can occur in two main forms. Acute onset of wheezing in an infant. This early wheezing defines recurrent wheezing in a child who does not have genetic predisposition to react to allergen, known as non-atopic infants or toddlers and tends to disappear by the age of three.
The most common cause for non-atopic wheezing is viral infection, especially by respiratory syncytial virus.
It is usually managed with short-term inhaled medicines that open up the airways such as ventolin or salbutamol.
This notwithstanding, some children with early sensitisation to indoor allergens, especially to pets can also have acute onset of wheeze and predict subsequent development of asthma.
The risk of asthma development is significantly increased with recurrent wheezing episodes and the development of allergic manifestations.
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Acute onset of wheezing can also result from abnormalities in the structure of the windpipe. These include webs and malformed vessels around the voice box and from structures that compress the trachea and surrounding structures be it from internal or external.
Recurrent or persistent wheeze is usually caused by obstruction anywhere from intrathoracic windpipe to large bronchioles. Wheezing persisting or recurring for more than four weeks is most commonly caused by reactive airways disease (asthma).
This diagnosis is also suggested by recurring cough and response to medicines that open up the windpipe.
As mentioned above, the commonest trigger tends to be viruses in children under five years. In addition, certain chronic conditions do cause persistent wheezing. Chronic lung diseases as seen in babies who are ventilated for a long time, children with congenital heart problems and in children suffering from asthma.
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In the latter, certain clues may point to it long before they become manifest. These signs include allergic rhinitis where their nose is constantly dripping, urticaria and eczema, which tend to be more pronounced at the flexures.
The treatment given by and large depends on the cause of the wheeze.
A member of Paediatric Society of Ghana