Differential Diagnosis for Anemia in a 75-year-old Woman with Aspiration Pneumonia
- Single most likely diagnosis:
- A. Anemia of chronic disease: This is the most likely diagnosis given the patient's chronic conditions such as rheumatoid arthritis and the presence of an acute infection (aspiration pneumonia). The elevated ferritin level (350) and low iron level (30) with a high total iron binding capacity (120) are consistent with anemia of chronic disease, where there is an inflammatory response leading to increased hepcidin levels, causing sequestration of iron and making it unavailable for erythropoiesis.
- Other Likely diagnoses:
- B. Anemia due to blood loss: Although less likely given the information provided (stool sample is brown and nonbloody, and no abdominal pain or mass), chronic blood loss could still be a contributing factor, especially if there are gastrointestinal lesions or other sources of occult bleeding not immediately apparent.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- C. Iron deficiency anemia: While the ferritin level is elevated, which typically argues against iron deficiency anemia, it's crucial not to miss this diagnosis, especially if there's a possibility of chronic occult bleeding. Mixed anemia (both iron deficiency and anemia of chronic disease) can occur, and iron deficiency anemia requires specific treatment.
- Rare diagnoses:
- Other rare causes of anemia, such as vitamin deficiency (B12 or folate deficiency), could be considered but are less likely given the patient's presentation and the information provided. These would typically require additional testing to diagnose and might not be immediately suspected without further clues (e.g., neurological symptoms for B12 deficiency).