A 35-year-old woman presents with swollen, painful joints. She recently had a throat infection which was not treated. Physical examination reveals a heart murmur. What might be the diagnosis and the cause of the symptoms?
The patient's symptoms of swollen, painful joints, recent sore throat, and new heart murmur suggest rheumatic fever, which is an inflammatory disease that can develop as a complication of inadequately treated strep throat infection. The patient likely needs urgent hospitalization and treatment with antibiotics, as well as further evaluation of the heart involvement with an echocardiogram.