Corticosteroids are drugs that are often used to treat asthma because they can help fight the inflammation that can occur in airways of the lungs, also known as the bronchial tubes. Most of the time, corticosteroids are taken into the lungs via an inhaler. These are known as inhaled corticosteroids.
However, this class of drug includes stronger versions that can be swallowed (or injected). Known as oral corticosteroids, they have names like prednisone or prednisolone, and can be used to more dramatically suppress inflammation during a serious asthma attack.
These so-called systemic corticosteroids are effective, but because they circulate throughout the whole body (rather than just the lungs), they can cause more serious side effects than inhaled corticosteroids. In children, systemic corticosteroids may cause slower or stunted growth, bone weakening, and skin-thinning, among other side effects.
Oral corticosteroids are generally used for shorter periods of time, and only when symptoms are very severe. When asthma is under control, patients may be switched to inhaled corticosteroids.