Differential Diagnosis
- Single most likely diagnosis
- Autoimmune gastritis: This is the most likely diagnosis given the patient's low iron and iron saturation levels, along with a positive parietal cell antibody test. The presence of parietal cell antibodies is a hallmark of autoimmune gastritis, which can lead to impaired iron absorption and subsequent deficiency.
- Other Likely diagnoses
- Iron deficiency anemia due to other causes (e.g., menstrual blood loss, gastrointestinal bleeding): Although the patient's laboratory results suggest autoimmune gastritis, other causes of iron deficiency anemia should be considered, especially if the patient has a history of heavy menstrual bleeding or gastrointestinal symptoms.
- Celiac disease: Celiac disease can cause malabsorption of iron and other nutrients, leading to deficiency. The patient's low iron levels and positive parietal cell antibody test do not rule out celiac disease, and further testing may be necessary to confirm or exclude this diagnosis.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Gastric cancer: Although less likely, gastric cancer can cause iron deficiency anemia and should be considered in the differential diagnosis, especially if the patient has other symptoms such as weight loss, abdominal pain, or difficulty swallowing.
- Gastric lymphoma: Like gastric cancer, gastric lymphoma is a rare but potentially life-threatening condition that can cause iron deficiency anemia and should be considered in the differential diagnosis.
- Rare diagnoses
- Atrophic gastritis due to other causes (e.g., Helicobacter pylori infection, chronic use of proton pump inhibitors): Although less common, atrophic gastritis due to other causes can lead to impaired iron absorption and deficiency. Further testing may be necessary to confirm or exclude these diagnoses.
- Rare genetic disorders (e.g., hereditary hemochromatosis, aceruloplasminemia): These disorders can affect iron metabolism and lead to deficiency or overload. However, they are rare and would require specific testing to confirm.