A 60-year-old female with a history of rheumatoid arthritis is experiencing shortness of breath. She has been taking methotrexate for her RA for the past five years. What could be the potential cause, and what are the next steps?
This patient's shortness of breath could be due to several potential causes, including lung involvement from rheumatoid arthritis itself, such as interstitial lung disease or pleuritis, or it could be a side effect of methotrexate, which can cause pulmonary toxicity. Alternatively, it could be due to unrelated cardiac or respiratory conditions. Further evaluation with a chest X-ray or CT scan, pulmonary function tests, and possibly echocardiography should be done to evaluate the underlying cause. If methotrexate-induced lung toxicity is suspected, discontinuation of the drug and rheumatology consultation should be considered.