IRON DEFICIENCY ANAEMIA
DEFINITION:
Iron deficiency anemia is caused due to deficiency of iron in the body. 20% of world’s population is suffering from iron deficiency anemia.
PATHOGENESIS:
It develops when supply of iron is insufficient for requirement of hemoglobin synthesis. Three major factors in pathogenesis of iron deficiency anemia are:
1. Increased Physiologic Demand - i.e. growing children, pregnancy, lactation and menstruating females.
2. Pathological Blood Loss - i.e. hemorrhage from GIT and urinary tract.
3. Inadequate Intake - i.e. nutritional deficiency or impaired malabsorption.
ETIOLOGY:
I. Due to increased blood loss
• Uterine - e.g. excessive menstruation in reproductive years, repeated miscarriages, at onset of menarche, postmenopausal uterine bleeding
• Gastrointestinal - e.g. peptic ulcer, hemorrhoids, hookworm infestation, cancer of stomach and large bowel, esophageal varices, hiatus hernia, chronic aspirin ingestion, ulcerative colitis, diverticulosis
• Renal tract - e.g. hematuria, hemoglobinuria
• Nose - e.g. repeated epistaxis
• Lungs - e.g. hemoptysis
II. Due to increased requirements
• Spurts of growth in infancy, childhood and adolescence
• Prematurity
• Pregnancy and lactation
III. Due to inadequate dietary intake
• Poor economic status
• Anorexia, e.g. in pregnancy
• Elderly individuals due to poor dentition, apathy and financial constraints
IV. Due to decreased absorption
• Partial or total gastrectomy
• Achlorhydria
• Intestinal malabsorption such as in coeliac disease.
CLINICAL FEATURES:
1. Anemia: Lassitude, weakness, fatigue, dyspnea, palpitations, angina, congestive cardiac failure and pallor.
2. Epithelial tissue changes
• Nails: Thin, lustureless, brittle, show ridging and flattening; presence of koilonychias.
• Tongue: Atrophy of papillae, shiny or glazed tongue, glossitis and angular stomatitis.
• Plummer-Vinson syndrome: It is characterized by chronic iron deficiency, dysphagia and glossitis.
3. Pica: It is defined as craving to eat substances like dirt, clay, salt, hair and is a typical manifestation of iron deficiency.
4. Recurrent infections: Iron deficiency leads to defective lymphocyte mediated immunity and impaired bacterial killing by phagocytes leading to impaired immunity and recurrent infections.
LABORATORY DIAGNOSIS:
I. General blood parametres
• Hemoglobin is decreased
• RBC count is decreased
• RBC indices, i.e. MCV, MCH and MCHC are reduced or low
II. Peripheral blood smear
It shows following features, i.e.
• Microcytic hypochromic cells, i.e. red cells are smaller than normal and have increased central pallor.
• Anisocytosis or variation in size of cell. This is indicated by increased red cell distribution width and is more marked in iron deficiency anemia.
• Poikilocytosis or variation in shape of cell, i.e. presence of tailed variety of RBC, elliptical form is common.
• In severe anemia there is presence of normoblasts, elliptocytes, pencil-shaped cells and target cells.
• There is presence of normal, increased or decreased platelet count and unremarkable WBCs.
III. Reticulocyte count: It is normal or decreased.
IV. Bone marrow
• There is presence of erythroid hyperplasia due to which marrow cellularity is increased
• In bone marrow prominent cell is polychromatic normoblast which is smaller than normal
• Cytoplasm shows ragged borders
• Cytoplasmic maturation lag behind that of nucleus
• Prussian blue stain show decrease in iron stores
V. Iron studies
• There is decrease in the serum iron
• Total iron binding capacity is high and rises to give less than 10% saturation
• Serum ferritin is very low which is indicative of poor tissue iron stores
• Red cell protoporphyrin is very low
• Serum transferrin receptor protein which is normally present on developing erythroid cells and reflects total red cell mass is raised in iron deficiency due to its release in circulation
0 Comments