The nurse is providing discharge instructions to a client with gout in the left great toe who received a prescription for prednisone 30 mg by mouth to be administered each day. Which symptom should the nurse explain is most important for the client to report to the healthcare provider?

A. Gastric Irritation. While gastric irritation is a common side effect of prednisone, it is not as critical as some other potential adverse effects and can often be managed with medication or dietary changes. B. Moon facies. Moon facies is a sign of Cushing's syndrome, a potential long-term side effect of prednisone, but it does not require immediate reporting compared to more acute symptoms. C. Abdominal striae. Abdominal striae (stretch marks) are a long-term side effect of corticosteroids like prednisone, but they are not typically an urgent concern. D. Rapid weight gain. This is the correct answer because rapid weight gain can indicate fluid retention, which may be a sign of more serious side effects such as heart failure or severe hypertension. It requires prompt medical attention to prevent further complications.