* Initial hemoglobin and red blood cell indices may be normal despite severe hemorrhage.
¶ Examples of possible conditions are provided within appropriate categories.
HGB: hemoglobin; MCV: mean corpuscular volume; TIBC: total iron-binding capacity; TEC: transient erythroblastopenia of childhood; G6PD: glucose-6-phosphate dehydrogenase; HUS: hemolytic uremic syndrome; TTP: thrombotic thrombocytopenic purpura; DIC: disseminated intravascular coagulation; HU: hydroxyurea; PMNs: polymorphonuclear cells; LDH: lactate dehydrogenase; DAT: direct antiglobulin test; RDW: red cell distribution width.
*Â HGB levels vary considerably by age, race, and sex; when diagnosing anemia, HGB values should be compared with age-, race-, and sex-adjusted norms. Mild anemia occurring at 6 to 9 weeks of life is consistent with “physiologic anemia” and is not pathologic. Falsely elevated HGB values may occur when measured using capillary samples (eg, finger or heel “sticks”), particularly when using microhematocrit measurements. Spurious results may also occur with automated counters in the presence of lipemia, hemolysis, leukocytosis, or high immunoglobulin levels.
¶ The RDW can be helpful in differentiating thalassemia from iron deficiency. High RDW is typical of iron deficiency, whereas the RDW is usually normal in patients with thalassemia (though elevated RDW can occur).
Δ Anemia of chronic disease typically presents as a normocytic anemia but can have low MCV.
â—ŠÂ Selected testing is based upon review of the patient’s history and examination of the peripheral blood smear.
¥ Evidence of hemolysis includes jaundice, indirect hyperbilirubinemia, elevated lactate dehydrogenase, and/or decreased haptoglobin.
‡ Findings on blood smear may suggest an underlying etiology of anemia, but they are generally not diagnostic. Further confirmatory testing should be carried out to confirm the diagnosis.
HGB: hemoglobin; MCV: mean corpuscular volume; PLT: platelets; HUS: hemolytic uremic syndrome; TTP: thrombotic thrombocytopenic purpura; DIC: disseminated intravascular coagulation; WBC: white blood cell; PMNs: polymorphonuclear cells; TIBC: total iron-binding capacity; LDH: lactate dehydrogenase; DAT: direct antiglobulin test.
*Â HGB levels in children vary considerably by age. During adolescence, HGB values also differ according to sex. When diagnosing anemia in pediatric patients, HGB values should be compared with age- and sex-adjusted norms. Mild anemia occurring at 6 to 9 weeks of life is consistent with “physiologic anemia” and is not pathologic. Falsely elevated HGB values may occur when measured using capillary samples (eg, finger or heel sticks), particularly when using microhematocrit measurements. Spurious results may also occur with automated counters in the presence of lipemia, hemolysis, leukocytosis, or high immunoglobulin levels.
¶ Findings on blood smear may suggest an underlying etiology of anemia, but they are generally not diagnostic. Further confirmatory testing should be performed to confirm the diagnosis.
Δ Selected testing is based upon review of the patient’s history and examination of the peripheral blood smear.
â—ŠÂ In children with mild microcytic anemia with thrombocytosis and a dietary history that is suggestive of iron deficiency, serum iron studies (ie, ferritin, iron, and TIBC levels) are generally not necessary. In these children, a therapeutic trial of iron can be used to confirm the diagnosis.