Iron Deficiency Anemia Diagnosis and Evaluation
Diagnostic Criteria
- The American Gastroenterological Association recommends a minimum initial workup for iron deficiency anemia, including complete blood count with red cell indices, reticulocyte count, serum ferritin, transferrin saturation, and CRP, to establish the diagnosis and guide management 1, 2, 3
- Anemia is defined as hemoglobin <13 g/dL in men and <12 g/dL in non-pregnant women, with iron deficiency confirmed by serum ferritin <45 ng/mL 3, 4
- Elevated red cell distribution width (RDW) indicates iron deficiency 1
Laboratory Testing
- The European Society for Medical Oncology recommends iron studies, including serum ferritin and transferrin saturation, to diagnose iron deficiency 4, 6, 7
- Reticulocyte count helps distinguish between defective erythropoiesis and hemolysis 1, 2
- C-reactive protein (CRP) is essential to interpret ferritin in inflammatory states 1, 2
Evaluation for Underlying Etiology
- The American College of Gastroenterology recommends non-invasive testing for H. pylori and celiac disease serologic screening before proceeding to endoscopy 3, 4, 7
- Bidirectional endoscopy (upper endoscopy and colonoscopy) is strongly recommended for all men and postmenopausal women with iron deficiency anemia 3, 4, 7
- Upper endoscopy detects pathology in 30-50% of patients and should include evaluation for peptic ulcer disease, erosive esophagitis, and gastric cancer 3, 8
Clinical History Priorities
- Focus the history on dietary iron intake, medication review, menstrual blood loss, prior gastrointestinal surgery, and family history of bleeding disorders or hereditary hematologic conditions 6, 8