BODY REQUIREMENT:• 0.8 – 1 mg of iron must be absorbed everyday for normal functioning in children below 15 yrs of age.
ABSOPTION:• It mainly occurs in the duodenum.• Absorption of dietary iron is assumed to be about 10% of the intake; so the daily diet should contain at least 8-10 mg of iron.TRANSPORT• Transferrin protein helps in the transport of iron in the circulation.
STORES:• Ferritin is an intracellular iron-storage protein.• Iron binds to ferritin and is stored in the cells. Ferritin that is not combined with iron is called apoferritin.• The body of a newborn infant contains about 0.5 g of iron, whereas the adult content is estimated to be 5 g.
• An infant is in a precarious (uncertain) situation with respect to iron. Should the diet become inadequate or external blood loss occur, anemia ensues rapidly.• Adolescents also are susceptible to iron deficiency because of high requirements due to the growth spurt, dietary deficiencies, and menstrual blood loss.
ETIOLOGY• In term infants iron deficiency anemia is unusual before 6 mo and usually occurs at 9-24 mo of age.• Low birth weight and unusual perinatal hemorrhage are associated with decreases in neonatal hemoglobin mass and stores of iron.
• Prolonged consumption of large amounts of cows milk ** (> 650 ml /day) along with foods not supplemented with iron.• Blood loss must be considered as a possible cause in every case of iron-deficiency anemia, particularly in older children.
• Occult bleeding may be caused by a lesion of the gastrointestinal tract, such as milk protein- induced inflammatory colitis, inflammatory bowel disease, peptic ulcer, Meckel diverticulum, polyp, or hemangioma.• Hook worm infestations.• H. pylori infection.• Chronic diarrhea in early childhood.
• Intense exercise especially in high schools girls results in iron depletion.• Delayed clamping of the umbilical cord (2 min) in developing countries may reduce the incidence of iron deficiency.
• In the advanced stages of iron deficiency anemia there are changes in the mucosa of the GIT , like the blunting of the villi , this causes bleeding and also prevents further iron absorption thereby worsening the anemia.
CLINICAL MANIFESTATIONS• PALLOR is the most important sign of iron deficiency anemia.• There are high rates of false positive and false negative results for palmer, nail bed and conjunctival pallor which vary according to the degree of anemia.
• PAGOPHAGIA, the desire to ingest unusual substances such as ice or dirt, may be present.• PLUMBISM may occur on ingesting lead- containing substances.• When the hemoglobin level falls to <5 g/dl, IRRITABILITY and ANOREXIA are prominent.
• Tachypnea, Tachycardia, weakness, cardiac dilation, dyspnea on exertion, systolic murmurs, CCF all are seen in severe anemia.• Child will have EVIDENT SIGNS OF POOR NUTRITION.• Iron deficiency anemia or iron deficiency with out anemia affects the attention span, alertness and learning in both infants and adolescents ( improvement was noted within 8 weeks of therapy).
INVESTIGATIONS• Serum ferritin gives us an accurate estimate of the serum iron stores and their levels are decreased in iron deficiency.• Serum iron levels decrease.• Serum transferrin levels increase ( i.e the iron binding capacity increases) and also the serum transferrin receptors.• The percentage saturation of transferrin falls below normal.
• The MCV, MCH, MCHC are all decreased.• As the deficiency progresses there is presence of microcytosis, hypochromia, poikilocytosis and increase RBC distribution width (RDW).• Absolute reticulocyte counts indicate an insufficient response to anemia.
The Bone marrow examination• Hypercellular with erythroid hyperplasia.• The normoblasts may have scanty, fragmented cytoplasm with poor hemoglobination.• Leukocytes and megakaryocytes are normal.• There is no stainable iron in marrow reticulum cells.In about 1/3 of cases, occult blood can be detected in the stool.
DIFFERENTIAL DIAGNOSIS1. Alpha and Beta thalassemia trait and other hemoglobinopathies ( in them the RBC count is elevated above normal despite the presence of a mild anemia and microcytosis, whereas in iron deficiency anemia RBC count usually decreases long with the reduced hemoglobin and MCV. Another difference between alpha and B-thalassemia trait and iron deficiency is that the RDW is elevated in iron deficiency.
2. The anemia of chronic disease (ACD) and infection usually is normocytic, although occasionally it may be slightly microcytic. Here serum ferritin levels are normal or elevated (ferritin is an acute phase reactant).• The serum transferrin receptor (TfR) level is elevated in iron deficiency and is within the normal range in anemia of chronic disease.
3. In cases of Lead Poisoning associated with iron deficiency the RBC’s are morphologically similar, but• Coarse basophilic stippling of the RBC’s often is prominent.• Elevated blood levels of lead, FEP- free erythrocyte protoporphyrins levels and urinary coproporphyrin levels .
TREATMENT• Oral administration of simple ferrous salts (e.g: sulfate, gluconate, fumarate) provides inexpensive and satisfactory therapy.• Older children and adolescents some times have GI complaints (constipation )• These can be over come by giving water with fibres , or giving iron with food though iron absorption may decrease.
• Therapeutic dose should be calculated in terms of elemental iron• 4-6 mg/kg /day of elemental iron in 3 divided doses provides an optimal amount of iron.
• Parenteral iron preparation (iron dextran) can be given, but occasional complication being anaphylaxis , another Parenteral form ferric gluconate can be given IV having less risk of anaphylaxis.• Iron medication should be continued for 8 wk even after the blood values return to normal.
• Family must be educated about the patients diet.• Milk consumption should be limited to a reasonable quantity, preferably 500 mL / 24hr or less. This reduction has a dual effect: The amount of iron-rich foods is increased, and blood loss from intolerance to cows milk proteins are reduced.
• Blood transfusion is indicated only when the anemia is very severe or when superimposed infection may interfere with the response to iron therapy.• Severely anemic children with hemoglobin values <4 g/dL should be given only 2-3 ml/kg of packed cells at any one time (furosemide also may be administered as a diuretic).
PREVENTION1. Use of Iron fortified formula’s or cereals in infants of high risk population, can reduce the risk of iron deficiency anemia.2. Adolescent females who develop iron deficiency due to abnormal uterine blood flow loss should be treated with iron and hormone therapy.