Tracheomalacia and Interstitial Pneumonia in a 95-Year-Old Woman With Undiagnosed Rheumatoid Arthritis: A Case Report.

This case report describes a 95-year-old woman with a history of cardiovascular and gastrointestinal diseases who presented with fever and anorexia. She was diagnosed with influenza A and secondary bacterial pneumonia. Despite antiviral and antibiotic treatment, her respiratory condition worsened. Detailed examination revealed characteristic joint deformities, elevated rheumatoid factor, and anti-cyclic citrullinated peptide antibodies. Imaging showed interstitial pneumonia and paradoxical breathing with elevation of the membranous portion of the trachea, indicating tracheomalacia. The patient was diagnosed with previously unrecognized rheumatoid arthritis with associated interstitial pneumonia and tracheomalacia. Immunosuppressive therapy with prednisolone and azathioprine improved her condition. This case highlights the importance of thorough systemic evaluation in elderly patients with unexplained respiratory symptoms and the need to consider late-onset autoimmune diseases, including rheumatoid arthritis, in the differential diagnosis.