The month of November brings with it a rise in childhood respiratory infections. Two of the most common, especially in younger children, are croup and bronchiolitis.
Croup is a diagnosis which can often be made while the child is still in the doctors waiting room. The giveaway is the seal-like "bark" which the unfortunate infant emits at regular intervals. While they are not distressed between episodes, a prolonged croupy cough can leave the child breathless.
The technically correct name for croup is laryngo tracheo bronchitis. This literally means an inflammation of the voicebox, the windpipe and the large breathing tubes of the lungs. It is caused by a viral infection, with the para influenza virus usually to blame. Croup comes on slowly, usually accompanied by running eyes and a runny nose. Most children with a simple croup, who are not short of breath, require no specific treatment apart from regular steaming. The moist air helps to reduce the swelling in the upper airways and will make the child more comfortable. The croupy cough usually disappears in a couple of days.
Children who have difficulty breathing with croup will require hospital admission for a tube to be passed down the airway in order to keep it open until the inflammation has subsided.
A much rarer cause of a croup-like sound, especially since the introduction of HiB vaccination, is epiglottitis. This means swelling of the "lid" which closes off our airway from the swallowing tube. In this case, the barking sound comes on much more quickly and severely, without any runny nose or eyes. The child will be unable to drink or swallow its own secretions, with the result that it will drool and be quite distressed. Epiglottitis is a more serious illness than croup, requiring urgent hospital admission for intubation by an experienced anaesthetist.
Bronchiolitis is an acute viral infection which occurs at the opposite end of the respiratory system. The swelling affects the smaller airways, below 1 mm in diameter, which are called bronchioles. Bronchiolitis mainly affects children under one year. A virus called the Respiratory Syncytial Virus (RSV) is the chief culprit. The illness occurs in winter epidemics between November and March. RSV is highly contagious and studies show that two-thirds of infants will have been infected by their first birthday and almost all before their second birthday.
Parents of children with bronchiolitis will usually say their infant has been feeding poorly and has developed a cough. The nose is extremely runny and it is possible to hear a wheeze even without a stethoscope. The doctor will hear fine crackles when he listens to the chest. A chest X-ray showing overinflated lungs helps to confirm the diagnosis.
Most cases of RSV are mild and self-limiting and do not require specific medical treatment. However, infants under two months of age may be a lot sicker with bronchiolitis. They may need hospital admission for oxygen therapy and intravenous fluids. Studies suggest that 2 per cent of children under one year with RSV bronchiolitis will require hospital admission.
Babies who are born prematurely (32 weeks or under) less than six months before the onset of the RSV season are at risk of a severe form of the disease. These babies in particular require hospital admission; many will need to spend up to eight days as inpatients requiring intubation and intravenous fluids.
Now, a treatment called Synagis, an antibody which reduces the risk of serious infection from RSV is available. It prevents the virus from penetrating the lower respiratory tract. Parents with premature babies should discuss the possibility of prescribing the new treatment with the child's paediatrician.
Parents of premature babies can do a lot to help prevent RSV getting hold in the first place by:
Not allowing smoking near the baby;
Only touching the baby after handwashing with soap and warm water;
Keeping the premature infant away from people with colds;
Not bringing the baby to crowded places.
Dr John Cosgrave, consultant paediatrician at Waterford Regional Hospital, anticipates an increased number of RSV cases this year. "For those premature infants that are high risk, I believe it is important to be prepared and to follow the above sensible advice."
Most children will fight off both bronchiolitis and croup without needing medical treatment. However, for those who do get a severe dose of bronchiolitis, one-third will still suffer from wheezy episodes up to 10 years later.
It therefore makes sense for parents of premature babies and of children with congenital heart disease to take all available precautions to prevent RSV infection.
Contact Dr Houston at mhouston@irish-times.ie or leave messages at tel 01-6707711, ext 8511. He regrets he is unable to reply to individual medical problems.