AAP policy statements, clinical practice guidelines, and model bills. Retrieved October 2000, from: and the American Academy of Pediatrics. Summary of AAFP policy recommendations and age charts. Baltimore, Md.: Williams & Wilkins, 1996 American Academy of Family Physicians. Guide to clinical preventive services: report of the U.S. Recurrent diarrhea raises suspicion of malabsorption and occult blood loss occurring in celiac sprue and inflammatory bowel disease. A recent viral illness may suggest red cell aplasia. Recent prescription drug use may suggest G6PD deficiency or aplastic anemia. A history of nutritional deficiency, pica or geophagia suggests iron deficiency. Pyruvate kinase deficiency is autosomal recessive and associated with chronic hemolytic anemia of variable severity. X-linked causes of anemia, such as glucose-6-phosphate dehydrogenase (G6PD) deficiency, should be considered in males. In premature infants, iron deficiency can occur only after the birth weight has been doubled. Therefore, in full-term infants, iron deficiency is rarely the cause of anemia until after six months of age. The newborn's body reclaims and stores iron as the hematocrit levels decrease during the first few months of life. Key historical points and findings on physical examination can reveal the underlying cause of the anemia. 2 Infrequently, a child with anemia may have pallor, fatigue and jaundice but may or may not be critically ill. Most children with anemia are asymptomatic and have an abnormal hemoglobin or hematocrit level on routine screening ( Table 1).
The relative quantities of HbF rapidly decrease to trace levels by the age of six to 12 months and are ultimately replaced by the adult forms, HbA and HbA 2 It has a higher affinity for oxygen than adult hemoglobin, thus increasing the efficiency of oxygen transfer to the fetus. HbF is the primary hemoglobin found in the fetus. There are six types of hemoglobin in developing humans: the embryonic, Gower-I, Gower-II, Portland, fetal hemoglobin (HbF) and normal adult hemoglobin (HbA and HbA 2). The hemoglobin molecule is a hemeprotein complex of two pairs of similar polypeptide chains. Normal RBCs survive an average of 120 days, while abnormal RBCs can survive as little as 15 days. Key steps in red blood cell differentiation include condensation of red cell nuclear material, production of hemoglobin until it amounts to 90 percent of the total red blood cell mass and the extrusion of the nucleus that causes loss of RBC synthetic ability. Postnatally, erythropoietin is produced in the peritubular cells of the kidneys. In the fetus, erythropoietin comes from the monocyte/macrophage system of the liver. 1Įrythropoietin is the primary hormone regulator of red blood cell (RBC) production. As many as 20 percent of children in the United States and 80 percent of children in developing countries will be anemic at some point by the age of 18 years. This form of anemia is uncommon in children.Īnemia is a frequent laboratory abnormality in children. Macrocytic anemia may be caused by a deficiency of folic acid and/or vitamin B 12, hypothyroidism and liver disease. The reticulocyte count will help narrow the differential diagnosis however, additional testing may be necessary to rule out hemolysis, hemoglobinopathies, membrane defects and enzymopathies. Normocytic anemia has many causes, making the diagnosis more difficult. Less common causes of microcytosis are thalassemia and lead poisoning. It is easily treatable with supplemental iron and early intervention may prevent later loss of cognitive function. The most common form of microcytic anemia is iron deficiency caused by reduced dietary intake. The use of the mean corpuscular volume to classify the anemia as microcytic, normocytic or macrocytic is a standard diagnostic approach. Multiple causes exist, but with a thorough history, a physical examination and limited laboratory evaluation a specific diagnosis can usually be established. Anemia in children is commonly encountered by the family physician.
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