Pediatric emergency medicine trisk 1195 1195

CHAPTER 62 ■ PALLOR SONAL N SHAH INTRODUCTION Pallor, or the absence of skin coloration, is a relatively common problem in childhood Throughout the world, the presence of pallor is often used as a screening tool to identify illness The development of pallor can be acute and associated with a life-threatening illness, or it can be chronic and subtle It may be first noted by someone who sees the child infrequently The onset of pallor can provoke anxiety for parents who are familiar with descriptions of the presentation of leukemia in childhood In some instances, only reassurance may be needed, as in the case of a light complexioned or fair-skinned, nonanemic child Even if there is a hematologic cause for the pallor, it is often a temporary condition readily amenable to therapy However, pallor can portend a severe disease, and especially when acute in onset, can herald a true pediatric emergency for which rapid diagnosis and treatment are essential The degree of pallor depends on the concentration of hemoglobin in the blood and the distribution of blood in the blood vessels of the skin Any condition that decreases the concentration of hemoglobin or alters the distribution of blood away from the body’s surface may present as pallor Clinically, pallor caused by anemia can usually be appreciated when the hemoglobin concentration is below to g/dL, although the complexion of the child and the rapidity of onset may influence this value DIFFERENTIAL DIAGNOSIS The differential diagnosis for nonhematologic causes of pallor is outlined briefly in Table 62.1 and hematologic causes in Table 62.2 The concentration of hemoglobin in the blood can be lowered by three basic mechanisms: decreased erythrocyte or hemoglobin production, increased erythrocyte destruction, and blood loss The most common causes of pallor and anemia seen in the emergency department (ED) are iron deficiency and blood loss ( Table 62.3 ), but several less common diseases remain important considerations Decreased Production of Hemoglobin and Red Cells Nutritional Anemias