Anemia in infancy and childhood. A systematic approach to evaluation.

The evaluation of the infant or child with possible anemia requires accurate testing and use of age-specific reference standards for normal values. Simple laboratory tests such as a well-performed peripheral smear to establish specific red cell morphology and red cell indexes to determine red cell size are useful to classify anemias as microcytic hypochromic, normocytic normochromic, or macrocytic normochromic. Addition of the reticulocyte index to these tests allows subdivision of these anemias according to three different pathogenetic mechanisms: hypoproliferation, hyperproliferation, or abnormal maturation of red cells. Patient management depends on systematic determination of the pathogenesis of the anemia, because some anemias are of a genetic origin and no specific treatment is needed, some are best treated by specific replacement, and some are dependent on treatment of the primary disease.