Q. I am having trouble differentiating between mild thalassemia and iron-deficiency anemia. I am not sure why the red cell distribution width would be lower in thalassemia than IDA. Could you please explain this and list other ways to tell them apart?
A. As iron-deficiency anemia progresses, and the patient’s serum iron drops lower and lower, each successive wave of new red cells gets smaller and smaller. So there are some kind of small cells, and some really small cells (as you can see in the image of iron-deficiency anemia above). The red cell distribution width (RDW) is high in iron deficiency anemia because there is a wide variation in red cell size. In mild thalassemia (alpha or beta), the red cells are strangely all the same size; there is virtually no variation. So the RDW is low. This difference in RDW is helpful when you’re trying to differentiate IDA and thalassemia; if you have a microcytic, hypochromic anemia, the next thing you’d do is look at the RDW (or just look at the blood smear). If the RDW is low (the cells are mostly the same size), then it’s probably thalassemia. If the RDW is high (the cells vary a lot in size), then it’s probably iron deficiency anemia.
Another thing to do is look at the RBC. In IDA, the RBC is low (there isn’t enough iron around, so the bone marrow makes fewer cells). In mild thalassemia, however, the RBC tends to be normal or even elevated. The reasons for this are unclear.
To definitively diagnose IDA, you need to do iron studies; to definitively diagnose thalassemia, you need to do hemoglobin electrophoresis. But you can get a pretty good idea by looking at the things discussed above.
We need your help! Pathology Student is completely ad-free.If you find us useful, please consider donating whatever feels right to you. Every bit helps!You can donate here.
- Kristine said I don’t think I have that phrase in my post – but I can comment on a few things. In anap...
- shadan said What do u mean by’ streaming nuclear polarity’ .
- Kristine said Sure! There’s a list of quizzes here, and there are a few more if you search for “quiz...
- Jovana said Thank you! Very usefull. ^^
- Akunwata Chima said I enjoyed your quiz. Can I have more?
- emad said Thanks alot ,
- kawi said Thank you very much …. I would like to learn more from you .
- felicia said thanks
- Lusi said Can’t wait to see it!!
- Kristine said Yes, I do! I plan to include it in that “all our books for X$” thing; it would be about...
- Joshua Smith said Looks fantastic, can’t wait to see it. Do you have any plans to include this in your “ge...
- akhtar said I am eagerly waiting for your book mam….and congratulation for it…!!!