What are the causes of a low Red Cell Distribution Width (RDW) differential?

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Differential Diagnosis for Low RDW

  • Single most likely diagnosis
    • Iron deficiency anemia: This is the most common cause of a low RDW (Red Cell Distribution Width) as it typically results in a homogeneous population of red blood cells, leading to a narrow distribution width.
  • Other Likely diagnoses
    • Thalassemia: Certain types of thalassemia, particularly alpha-thalassemia, can present with a low RDW due to the uniform size of the red blood cells.
    • Anemia of chronic disease: In some cases, anemia of chronic disease can have a low RDW, although this is less common than other causes.
  • Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
    • Sickle cell disease: Although less common, sickle cell disease can sometimes present with a low RDW, especially in cases where the disease is well-compensated or in the early stages.
    • Polycythemia vera: A myeloproliferative disorder that can lead to an increase in red blood cell mass, sometimes presenting with a low RDW due to the uniformity of the red blood cells.
  • Rare diagnoses
    • Hereditary spherocytosis: A rare genetic disorder characterized by the production of abnormal, sphere-shaped red blood cells, which can sometimes present with a low RDW.
    • Other rare hemoglobinopathies: Certain rare hemoglobinopathies, such as hemoglobin C or E, can also present with a low RDW, although these are less common than other causes.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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