Asthma in babies and very young children is usually blamed on virus infections which damage the cells lining the airways, causing them to become hypersensitive and inflamed. Infants often develop asthma after having a series of viral infections, usually ‘one cold after another’ or flu. However, there is an unresolved ‘chicken and egg’ argument about the role of allergy in this type of asthma.

Some scientists believe that babies are particularly susceptible to allergy because their immune systems are poorly developed. They point out that, as a result, the lungs of the babies are particularly susceptible to many common allergens such as house dust mites, or to irritants such as tobacco smoke. They believe that a virus infection in only leads to asthma in babies and small children whose airways were already primed by an allergic reaction. If this turns out to be true, then in the future some types of asthma could be avoided by protecting very young children from exposure to allergens, either by adjusting their living conditions, or by vaccination.

However, other researchers believe that it is the damage caused by the virus that primes the baby’s airways to over-react to allergens and irritants, thus leaving the child with a higher chance of developing asthma later in life. At present these arguments do not affect the treatment for asthma a child is likely to receive.

Many young children and even babies suffer from asthma. This form of asthma may be caused by viral infections, especially in babies who are susceptible to allergies. Parents of children who wheeze or have a troublesome cough should consult their doctor or medical physician for further asthma testing.