This information is for parents of a baby or young child with wheezing. It tells you about steroid tablets, a treatment used for more severe wheezing in babies and young children. It is based on the best and most up-to-date research.
Do they work?
Steroid tablets are often used in hospital for babies and young children who get more severe wheezing. They're used together with other treatments. These drugs have been used for a long time, and doctors think they work. But there's not much research on them.
What are they?
Steroids are anti-inflammatory medicines. They calm down and prevent swelling (inflammation) in the airways of children with asthma.
If your child is having moderate or severe asthma attacks, your doctor may prescribe the steroids as tablets or a liquid, usually for about three days, to bring his or her asthma under control.
The name for steroid tablets used to treat asthma is prednisolone (brand name Deltacortril).
Steroids used to treat asthma are not the same as anabolic steroids used by some athletes and bodybuilders. In fact, asthma steroids are a direct copy of steroids produced naturally by our bodies to deal with inflammation. To learn more, see More about steroids and asthma.
How can they help?
If your child has a moderate to severe asthma attack and is taken to the accident and emergency department in hospital, your doctor may prescribe steroid tablets.
Often this is just one part of the treatment. Children may also be given other drugs or oxygen. This is because steroid tablets take three to four hours to work. Once your child's asthma is under control and you return home, he or she may be given steroid tablets for a few days. This is to help prevent your child having another attack.
Steroid tablets are helpful in treating asthma attacks in older children. Doctors think they also help younger children. But there's not much research on this.
How do they work?
Children who have asthma have swollen air passages. Steroids help because they open up the airways by reducing the swelling. They also help prevent further inflammation. This makes it easier for your child to breathe, and reduces wheezing.
Steroid tablets work by getting into the cells in the lining of the airways and sticking on to specific sites in these cells (called receptor sites). Once inside, they stop cells from producing chemicals that cause inflammation.
If the airways are less inflamed, they are less likely to be extra-sensitive to asthma triggers such as allergens.
Can they be harmful?
Steroid tablets have side effects, which can sometimes be serious. But when steroids are used as an emergency treatment for severe asthma, they're only given for a few days. Because your child will only be taking them for a short time, it cuts the risk of side effects. 
If your child gets any worrying symptoms while they're taking steroids, take them to see a doctor straight away.