Clinical Manifestations And Investigations In Determining Nutritional Megaloblastic Anemia
An Anemic Face
The onset is insidious. Pregnant women and children are more affected. In addition to the general features of anemia, certain distinguishing features seen are;
- Large beefy tongue
- Dark pigmentation over the palms, soles, face and tongue
- Hepatosplenomegaly; and
- Mental changes and neurological involvement in vitamin B12 deficiency.
Neurological abnormalities include peripheral neuropathy and degeneration of the posterior column and pyramidal tracts- subacute combined degeneration. Psychiatric disturbances and optic neuritis may occur in a few.
Hemoglobin level may vary from 5 to 8 g/dl or less, MCHC is within the normal range (28-32%) while MCV is increased and may be as high as 120 fl. Macrocytosis and anisopoikilocytosis are easily recognizable. Some red cells may show punctuate basophilia due to the presence of remnants of ribonucleic acid. Nuclear material may be present in erythrocytes. These are seen as Howel-Jolly bodies and Cabot’s rings. Leucocytes may be normal or decreased in number. Granulocytes are larger than normal, showing increased lobulation with the average lobe count higher than 5 (macropolycytes). This change in leucocytes is very helpful in diagnosis when the morphology of erythrocytes is equivocal. Platelet count may be decreased at times.
Bone marrow is hyperplastic due to erythroid hyperplasia. All stages of megaloblasts are present. Normoblastic erythropoiesis may also be present simultaneously. In the absence of iron deficiency hemosiderin content of marrow is increased. Life span of red cells is moderately decreased. Serum iron level may be increased if there is no iron deficiency.
Levels of serum folate and red cell folate are diminished. The normal level of folate in serum is 6-20 ng/ml and that in red cells is 160-640 ng/ml. Serum levels below 3 ng/ml and red cell levels below 100 ng/ml indicate deficiency of folate. Serum vitamin B12 values below 100 pg/ml are indicative of deficiency.
Severe cases of Anemia
Treatment And Prevention
Overall dietary correction should be undertaken. Oral administration of 1 mg or more of folic acid daily is adequate to correct folate deficiency. Supplementation of folic acid will improve the anemia due to deficiency of vitamin B12 also, but not the neurological complications. In the later stages of therapy, deficiency of Iron may develop and Iron may have to be given.
Vitamin B12 deficiency can be rapidly corrected by intramuscular injection of 1000 ug of hydroxocobalamin. Oral doses of 1-2 ug are curative in most cases if continued over a few months.
Supplementation of folates to pregnant women, children and subjects receiving antiepileptic drugs, helps in preventing folic deficiency. In pregnancy, a daily dose of 0.5 mg of flic acid should be given prophylactically from the first trimester. Where megaloblastic anemia has developed 5 mg should be given orally daily throughout the pregnancy and puerperium. Prophylactic administration of 10 ug of vitamin B12 orally daily during pregnancy safeguards against deficiency. Infants require 1 mg of folic acid orally daily as supplement.
© 2014 Funom Theophilus Makama