I've been on prednisone for better than two years, dropping form a high of 60 mg to now 7.5 mg. I required it a rare pneumonia, and asthma. The result has been good, but the downside has been a depressed immune system opening me up to bacteria of opportunity. As the tapering has continued my immune system has improved. RELY on the advice of you doctor in this case, and try to have a complete explanation of what to expect. The x ray is indicative of the need for the prednisone - that is what indicated m start, in addition to a blood test CRP, I believe.