Oral, or systemic, corticosteroids quickly help out of control asthma, but more than two weeks of daily use may sometimes lead to serious side effects. Inhaled corticosteroids are considered much safer for lengthier treatment. Unlike the oral forms that must travel throughout your body to reach your lungs, inhaled corticosteroids are delivered directly to the airways in small doses with less chance of reaching other parts of the body. You have probably read or heard varying reports about the risks of corticosteroid use. The bottom line is that the relatively few side effects are usually balanced by the good they do for your asthma.
Steroids are definitely safe when used in the lower dosage range.
Problems generally arise with high doses over long periods of time. As consumers and patients, it's important to know what specific side effects may occur and how we can work with our physicians to control them and our asthma. Only 10 percent to 30 percent of inhaled steroid doses actually reach the lungs. The remainder is left in the mouth or throat or is swallowed, sometimes resulting in thrush, a fungal infection that produces milky white lesions in the mouth. Clinical thrush is far less common in lower dosages and affects more adults than children.