What is the workup for Iron Deficiency Anemia (IDA)?

From the Guidelines

The workup for iron deficiency anemia (IDA) should begin with a complete blood count (CBC) with differential, peripheral blood smear, and iron studies including serum iron, total iron binding capacity (TIBC), transferrin saturation, and ferritin, as a low ferritin (<30 ng/mL) is the most specific test for diagnosing IDA 1.

Initial Evaluation

The initial evaluation of IDA should include:

• A complete blood count (CBC) with differential to assess the degree of anemia
• Peripheral blood smear to evaluate the morphology of red blood cells
• Iron studies, including serum iron, total iron binding capacity (TIBC), transferrin saturation, and ferritin, to confirm the diagnosis of IDA
• Reticulocyte count to assess the bone marrow's response to anemia
• Vitamin B12 and folate levels to rule out other causes of anemia
• A comprehensive metabolic panel to evaluate for other potential causes of anemia

Additional Testing

Additional testing should be guided by the patient's clinical presentation and may include:

• Gastrointestinal evaluation, including upper endoscopy and colonoscopy, to identify potential sources of blood loss, especially in men and postmenopausal women 1
• Gynecological evaluation for premenopausal women with heavy menstrual bleeding
• Celiac disease screening with tissue transglutaminase antibodies, particularly in patients with other suggestive symptoms
• Hemoglobin electrophoresis to rule out thalassemias in certain populations
• Bone marrow examination, which is rarely needed but may be considered in cases where the diagnosis remains unclear despite initial testing

Monitoring and Treatment

Regular monitoring of hemoglobin (Hb) levels is recommended to ensure an ultimately satisfactory response to treatment, with the optimal interval being every 4 weeks until the Hb is in the normal range 1. The treatment of IDA typically involves oral iron supplementation, with a once daily dose of 50-100 mg of elemental iron being a reasonable initial treatment option 1. However, the optimal drug, dosage, and timing of oral iron replacement therapy (IRT) for adults with IDA are not clearly defined, and the effect of alternate day therapy on compliance and ultimate haematological response are unclear 1.

From the Research

IDA Workup

• Iron-deficiency anemia (IDA) is a common condition that requires a thorough workup to determine the underlying cause and develop an effective treatment plan 2, 3, 4.
• The workup for IDA typically involves a combination of laboratory tests, medical history, and physical examination to identify the cause of iron deficiency and assess the severity of anemia 4, 5.
• Laboratory tests may include:
  • Complete blood count (CBC) to evaluate hemoglobin levels, mean corpuscular volume (MCV), and red blood cell distribution width (RDW) 5.
  • Serum ferritin levels to assess iron stores 2, 4, 5.
  • Serum iron and total iron-binding capacity (TIBC) to evaluate iron availability and binding capacity 4.
• Medical history and physical examination may reveal underlying causes of iron deficiency, such as:
  • Gastrointestinal bleeding or inflammation 3, 4.
  • Menstrual bleeding or pregnancy 3, 4.
  • Chronic diseases, such as kidney disease or cancer 3, 4.
• Treatment of IDA typically involves oral iron supplementation, which is usually efficacious in correcting iron-deficiency anemia and replenishing iron stores 2, 5.
• However, oral iron supplementation may cause gastrointestinal side effects, and intravenous iron therapy may be necessary in some cases, such as when oral iron is contraindicated or ineffective 2, 3, 6.