Diagnostic approach to the child with anemia and abnormalities of other cell lines

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.

* 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.

◊ 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.