NMS Q&A Family Medicine

320 NMS Q&A Family MedicineExamination Answers1. The answer is C. Sideroblastic anemia is the one choicethat is not normally an example of microcytic anemia.This disorder results from inability to incorporate ironinto the protoporphyrin in the erythropoiesis process. Aprominent characteristic is accumulation of iron as ironabsorption is accelerated in response to low hemoglobin,resulting in elevated serum iron and transferrin saturation,although not to the level found in hemochromatosis;usually this produces a macrocytic or normocytic situation.A classic cause is a generalized marrow disorder andmay culminate in myelodysplasia. Cases that may be secondaryto lead poisoning account for some of the fewinstances in which sideroblastic anemia manifests microcytosis.Each of the other conditions presented is characterizedby microcytic anemia, that is, thalassemia, irondeficiency, and anemia of chronic disease. The latter iseither normocytic or microcytic.2. The answer is B. Lead poisoning harms by neurologicaland GI symptoms and pathology. Only 25% are anemicand the anemia tends to be mild, so that iron storageis not a great part of the clinical picture. Hemochromatosisis defined by pathological storage of iron. Thalassemiais a multivariate disease but when clinically expressed thehemoglobin runs 6 to 10 gm/dL due to hemolysis, and thetendency for overabsorption of dietary iron is inverselyrelated to the hemoglobin level. SCD is of course alsointensely hemolytic, and iron storage is a characteristicfor the same reason. Sideroblastic anemia has severalcauses, but the pathophysiology of each of them featuresblocked erythropoiesis, and the resultant low hemoglobinhas the same effect on iron absorption as do the hemolyticanemias. The measure of elevation of the process ofiron storage is transferrin saturation (occupation ofgreater proportion of the transferrin molecule, the vehicleof transport), and the measure of total body storage isserum ferritin. These parameters are not very prominentin the non-iron deficiency anemias as they are in hemochromatosis.3. The answer is C. Heavy alcohol intake, unless complicatedby GI bleeding, does not impede oral iron absorption.In fact, regular ingestion of alcohol increases GIabsorption as does large dosages of ascorbic acid andinflammatory hepatic disease. Each of the other factorsmentioned may be a cause of failure of iron deficiency torespond to oral iron.4. The answer is A. Essential thrombocytosis often featureserythromelalgia, described in the vignette. The conditionis characterized by platelet counts for up to2 million/dL without significant other abnormalities offormed peripheral blood elements. It occurs predominantlyin the 50 to 60 years age group, and incidental discoveryof the elevated platelet count is the most frequentpresentation. Other cases are found because of the occurrenceof frequent thromboses in unusual sites such asmesenteric, hepatic, and portal veins. Treatment withhydroxyurea to keep the platelet count at 5,00,000 orbelow is the therapeutic approach. Raynaud disease featuresthe Raynaud phenomenon wherein the finger tipsexhibit pain and color changes, usually demarcated at theproximal interphalangeal joints (PIP). The attacks areprecipitated by exposure to cold, the opposite in thatregard to erythromelalgia. Secondary syphilis manifestsgeneralized macular non-pruritic lesions that the palmarand solar areas. Dyshidrotic eczema occurs on the palmsand soles as pruritic lesions with mild tendency to desquamation.Myelodysplasia is a group of diseases that featurecytopenias with hypercellular marrows and morphologicabnormalities in two or more hematopoietic cell lines.Sometimes, the collective diseases are classified as “preleukemias”because many cases evolve into myeloid leukemia.Usually, symptomatic presentation is based onclinical marrow failure with fatigue, infection, or bleeding.There is no particular acral dermatologic manifestationwith this group of diseases.5. The answer is B. One to two months is the low point ofhemoglobin and the level at which it remains until the childreaches about the age of 8 years. In a comparison of theanalogous hematocrit level, the months of 3 to 11 reveal arelative hypochromia (hemoglobin-to-hematocrit ratio of 1:3). This begins to be corrected after the growth rateslows markedly after the child’s first birthday. If we assumethese data apply to the population at large and all socioeconomicgroups, then the reason for the lag in correction tothe teen levels is quite likely due to iron deficiency, whichreflects the rapid growth in the 1st year that outruns thedietary iron. The latter reveals that too often the hemoglobinof the growing infant is still not checked frequentlyenough or that iron-fortified formula is not being prescribedas a routine in the majority of well baby care practice.Either is acceptable, as some practitioners prefer toforego iron-fortified formula because of frequent GI sideeffects, usually hard stools. In lieu of fortified formula,hemoglobin should be checked by about 9 months; in manycases, iron should be prescribed separately when needed.6. The answer is C. Variability of red cell width (range ofRDW) is increased in iron deficiency. MCV is lower thannormal in iron deficiency (i.e., the anemia is microcytic).