A 34-year-old woman with ulnar deviation and MCP/PIP joint pain presents with a heart problem consistent with pericarditis. Which diagnosis best fits this scenario?

• A. Pericarditis Associated With Autoimmune Diseases (e.g., RA or SLE)
• B. Acute Coronary Syndrome
• C. Aortic Aneurysm
• D. Pulmonary Embolism

Answer: (A)

The main idea here is recognizing that pericarditis can be a serious extra-articular manifestation of autoimmune inflammatory diseases, especially rheumatoid arthritis. The joint findings—ulnar deviation with MCP and PIP joint pain in a young woman—strongly suggest inflammatory arthritis, most classically rheumatoid arthritis. RA and other autoimmune conditions like SLE frequently involve the pericardium, leading to pericarditis. So the scenario fits best with pericarditis that arises in the setting of autoimmune disease.

Why the other options fit less well: Acute coronary syndrome would be less likely in a relatively young patient without classic cardiovascular risk factors and wouldn’t specifically connect to inflammatory joint disease. An aortic aneurysm is uncommon in someone this age without risk factors and would present differently, with signs like back or chest pain and possible pulse abnormalities. Pulmonary embolism would present with sudden pleuritic chest pain and dyspnea and has risk-factor associations that don’t tie directly to the joint findings here.

So the best fit is pericarditis associated with autoimmune diseases such as RA or SLE.