BRONCHIOLITIS: Confined to children under the age of two. It is usually due to the respiratory syncytial virus but may have secondary bacterial invaders.
It involves the smallest of the airways — the bronchioles — as well as the larger bronchi.
The illness often starts as a rather mild infection with a nasal discharge and slight cough, then suddenly worsens with a harsh dry cough, wheeze and respiratory distress. Fever is slight or absent.
The child is obviously ill and in distress and rib retraction is noticeable on looking at the chest. Most cases need admission to hospital for treatment.
WHEEZY BRONCHITIS: Some children develop a wheeze with each respiratory infection. It may be difficult to distinguish between wheezy bronchitis and asthma triggered off by infection.
ASTHMA: Is a spasm or tightening of the muscles in the bronchial tubes, a swelling of their lining, and an excess of mucus, all of which produce a wheeze.
The three factors which cause asthma may act singly or together. They are allergy, infection and emotion.