Microcytic Anemia and Iron Deficiency- A Discussion Group
| Authored: Fri, Nov
25, 2005, 6:48 PM What is the differential diagnosis of childhood microcytic anemia? Dr Sheth provided this excellent account of how to think about iron deficiency anemia...We would like to extend an invitation to some of the other hematologists and generalists, if they have any other comments or cases with regards to this topic. Thanks. Dr. Sujit' Sheth's initial responses: Differential of Microcytic Anemia Amount
of Iron to be given to Treat Iron Deficiency Comments
made by other providers follow: By Dr. Kenny Katz First of all, it is always intimidating to try and add anything to an answer by Sugit. I will say that I rarely get a lot of labs for an infant or toddler with anemia unless the PE is suggestive of serious illness or there are disturbing symptoms. I assume any anemia picked up on screening or clinically is iron deficiency (based on nutrition) and embark on a treatment trial of 2-3/kg of elemental iron, preferrably divided BID and given at least an hour before or after milk ingestion. I followup 7-10 days later and should see a bump in the HCT of about 1 point a day after the initial 2-3 days. If there is a good response , I repeat the HCT in another week and then if it is still climbing , I continue the RX for 3 months to replenish the stores. If there is an unsatisfactory response, I will do a workup starting with a guiac, and if there is microcytosis, I get an electrophoresis and a lead, as well as iron studies, as described by Sugit. Hope this wasn't redundant. Kenny
With respect to iron deficiency I think there is point that we miss quite often when the issue is discussed and that is that ANEMIA IS THE FINAL STAGE. Screening for Iron Deficiency by Drs. Ann Chen Wu, Leann Lesperance and Henry Bernstein in Pediatrics In Review Vol23, 2002; pg171-178. They do an excellent job describing iron deficiency with and without anemia. There are effects to living in iron deficiency and they relate to development. Iron has many effects including brain development and function. The CLASSIC ARTICLE is in NEJM in 1993 by Dr.Oski where he discusses the neurodevelopmental (occasionally permanent) changes that go on in an iron deficient state. Therefore it is important to remember that even when the Hgb rises the job is not done as Kenny has stated above. I remember this all because of an anecdote that Kenny told me when he was my clinic attending. I will attempt to paraphrase- Kenny had a patient whom had been diagnosed with anemia and when he recommended iron the mother asked if there were any side effects she needed to watch out for. Kenny mentioned many the stool color changes but said otherwise not really. The background on the kid was that he was a pretty hyperactive child and a historically poor sleeper. Well a few months later the mother came storming in to the office wondering what had Kenny done to her child with the iron because he was now sleeping through the night (why she was upset I am not sure) and that the iron must be sedating... In truth, the iron deficiency was likely the etiology of his hyperactivity/developmental issues. Another pearl I learned from Hetty Cunningham in clinic is after age 1 always ask how many bottles (hopefully cups but one issue at a time) of cow's milk does the child drink in a day... You'll be surprised that some of the 15-18 month old children are still taking up to 40-60oz/day (5-8 bottles). The parents still believe that the milk is a key to the toddler's diet as it was during infancy - You can make an easy dietary intervention here prior to reaching anemic states. Hope this was helpful and not too preachy - in the immortal words of Bartels and James thank you again for your support. Dan I agree with Sujit, Dan and Kenny, but I want to emphaisze that iron deficiency, while decreasing somewhat in prevelance, is still very common in toddlers who often replace infant formula with iron poor diets (too much milk and juice being the primary culprit). Most studies in inner city communities have found that about 20% of toddlers are iron deficient and about 10% have iron deficiency anemia. Given the developmental consequences of iron deficiency this is one of the most common treatable diseases we see. We should screen all two year olds for anemia and, since half of kids who are iron deficient are not anemic, we should consider routine iron supplementation in toddlers who have iron poor diets (many of the kids who take more than 24 oz milk/day). Mary As usual, Sujit got it right, and so has everyone else for that matter. The combination of prophylaxis and prompt intervention by primary care pediatricians has greatly reduced the number of children with iron deficiency who need to see a hematologist. That's just fine with us. We salute all of you who have made this a rare disease for the tertiary care center. By the way, the only time I ever had to transfuse a child with iron deficiency was when a rotund Michelin Tire one-year old was carried in with a Hgb of 1.5 and a Hct of 6 in high-output failure. A few ml of packed cells and he was fine. I've never had to use parenteral iron. John Truman Everyone's point is well-taken. If I may just add another point - it is often easy to make a diagnosis of iron deficiency anemia (based on CBC and iron studies) and it is easily treated with oral iron supplementation; however, we should also not forget to think about the SOURCE or CAUSE of the iron deficiency. Although nutritional deficiency is the most common cause as we typically see in toddlers, one would not want to miss the atypical patient outside of this age range who develop iron deficiency because of more serious causes like GI bleed. I always like to tell this anecdote of a 7y/o boy who was referred to a hematologist because of microcytic anemia that was easily confirmed as iron deficiency. Thankfully, the work-up did not end there. As this was not a typical age for presentation of iron deficiency that can be explained by inadequate nutrition, a search for a source of iron (blood) loss was done. The child turned out to have occult GI bleed from a lymphoma. Margaret I fully agree with all the excellent comments made. One interesting point I learned a long while ago is if you suspect beta thal trait it may be wise to put the patient on a few weeks of iron before getting a Hgb A2 as the iron deficiency that may accompany the thal trait may inhibit the elevation in the Hgb A2. Of course, if you suspect alpha thal trait, this will not be relevant. I understand that alpha thal trait is the most common cause of microcytosis in older African Americans. Unfortunately, it often is a diagnosis of exclusion. Fred Bomback All I can say is that I am glad that we were able to get such a nice discussion going. All of the points made are excellent and there is nothing like a good anecdote to keep something in one's memory. I agree with Kenny that any child between 1 and 5-6 who has MICROCYTIC anemia should be treated with iron as a therapeutic challenge and the hemoglobin should go up as he described. Margarets' point about finding the cause of the iron deficiency is also well taken. In most cases it is dietary - from too much milk, as Hetty(through Dan!) and mary have said. But the next most common cause would be blood loss - again most often from the GI tract. This brings up an interesting question. Milk protein allergy can make you lose blood in the stools as well. So a stool guaic will be positive in such instances, as also in someone who is losing blood from some other GI lesion. So doing a stool guaic, or 3 which is ideally recommended, would not help decide who needs a further GI workup. In this instance, one approach would be to completely cut milk protein out of the child's diet - not an easy thing to do, and retest the stools using hemoccult - since the guaic may be positive if the child has been started on iron (which should absolutely be done). So invariably, if the stool guaic is positive to begin with, a GI workup should be done. And all children with suspected iron deficiency anemia who have a reported reasonable iron intake should have stool guaic testing done. Fred's point is an excellent one which many do not remember. If there is microcytic anemia, do not send the electrophoresis until after a "trial" of iron has been given, or normal iron studies documented. Of course at the cost of sounding like a nag, the
most important intervention is still primary prevention. Counseling
mothers that weaning should begin at the appropriate time and that
weaning foods should be balanced to include all the food groups including
those "nasty" green leafy vegetables that their toddlers
will love so much. See also this Virtual Preceptor Question to Dr Sheth for the evaluation of iron treatment http://wbc.babiespeds.org/vp/show_question.php?vp_id=175 A great case from Patient of the Week. Regarding severe iron deficiency anemia and concomittant thrombocytopenia. Basically there are case reports of severe iron deficiency also depressing platelet production and once you start the iron you get a responding thrombocytosis - here is one of the cases presented: I saw a similar patient a year or so ago. She was about 14 yrs old with a history of heavy menses and was admitted with a Hb 2 g/dl and MCV <50, after going to the doctor because a relative thought she looked pale. She was asymptomatic, HR in the 80s, no orthostasis, and was not menstruating at that time. She actually was pancytopenic with ANC less than 1000 and plt in the 50K range. Iron studies indicated iron deficiency. Her diet was poor, mostly soda, cereal, and chips. On direct questioning, she admitted to eating cornstarch baby powder, 3-4 large containers per week! Because she was so well compensated and not bleeding at the time, and the history was so classic, I decided to treat her with oral ferrous sulfate in the hospital and did not do a bone marrow aspirate. She was discharged with a Hb of about 4 g/dl, also on oral contraceptives. Five days later it was up to 7 g/dl, WBC had normalized, and she had the expected thrombocytosis. She was lost to followup. What amazed me was that someone must have been buying the baby powder for her. I think her family knew she was eating it but I guess this didn't register as really abnormal. She said it tasted good, but when her Hb was rising she said she didn't really want to eat it anymore. I was so impressed by her pica that I will remember this for a long time. Monica Hulbert, MD |
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