Does asthma affect a child's development?

No. If asthma is poorly controlled in children, they may be excluded from some physical activities or be picked-on by other children. This could affect social development however, physical development would be expected to be normal, even among children who use inhaled steroids.
Possibly. Poorly controlled asthma can affect the development of a child. It is essential to make sure your child's asthma in under good control!