Differential Diagnosis
The patient's complex medical history and presentation require a thorough consideration of various diagnoses. The following categories outline the potential causes of her symptoms:
- Single most likely diagnosis
- Reactivation of Coxiella burnetii endocarditis: The patient's history of Q fever endocarditis, recent cessation of etanercept, and symptoms such as night sweats, weight loss, and abdominal discomfort suggest a possible reactivation of the infection. The fact that she has been on lifelong doxycycline treatment but stopped etanercept five months ago could have led to a resurgence of the infection.
- Other Likely diagnoses
- Rheumatoid arthritis flare: The patient's history of rheumatoid arthritis and recent cessation of etanercept could contribute to a flare of her autoimmune disease, leading to symptoms such as abdominal discomfort, nausea, and unintentional weight loss.
- Splenomegaly-related symptoms: The patient's enlarged spleen could be causing abdominal discomfort, nausea, and vomiting due to splenic infarction or other complications.
- Gastrointestinal infection or inflammation: The patient's symptoms of abdominal discomfort, nausea, vomiting, and alternating constipation and loose stools could be indicative of a gastrointestinal infection or inflammation, potentially related to her immunosuppressed state.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Lymphoma: The patient's history of rheumatoid arthritis, recent weight loss, night sweats, and unintentional weight loss raise the possibility of lymphoma, which can be associated with chronic inflammation and immunosuppression.
- Sepsis: Although the patient does not have fevers or chills, her immunosuppressed state and history of endocarditis make her susceptible to sepsis, which could be life-threatening if not promptly recognized and treated.
- Valve dysfunction or prosthetic valve thrombosis: The patient's history of prosthetic aortic valve replacement and recent symptoms such as shortness of breath and mild cough could indicate valve dysfunction or thrombosis, which would require urgent attention.
- Rare diagnoses
- Whipple's disease: This rare bacterial infection can cause symptoms such as weight loss, abdominal discomfort, and diarrhea, and is often associated with immunosuppression.
- Amyloidosis: The patient's long-standing rheumatoid arthritis and recent symptoms such as weight loss and abdominal discomfort could be indicative of amyloidosis, a rare condition characterized by the deposition of abnormal proteins in various organs.