Description
Megaloblastic anemia in children is characterized by abnormally large red blood cells (megaloblasts) and is primarily caused by deficiencies in vitamin B12 or folate. A clinical approach to megaloblastic anemia in children begins with a thorough medical history and physical examination to identify potential risk factors and symptoms. Common symptoms of megaloblastic anemia in children include fatigue, weakness, pale skin, shortness of breath, and poor appetite. Laboratory tests, including complete blood count (CBC) and peripheral blood smear, are essential to confirm the diagnosis and assess the severity of anemia. The measurement of serum vitamin B12 and folate levels is critical in determining the underlying cause of megaloblastic anemia. In cases of suspected vitamin B12 deficiency, intrinsic factor antibodies and methylmalonic acid levels are additional tests that aid in diagnosis. Identifying the cause of megaloblastic anemia is crucial to guide appropriate treatment and prevent potential complications. Dietary history and nutritional assessment are essential to determine if the child's megaloblastic anemia is due to inadequate intake of vitamin B12 or folate.
Management of megaloblastic anemia often involves vitamin supplementation, either orally or through intramuscular injections, depending on the underlying deficiency.
Résumé
- Megaloblastic anemia is characterized by large red blood cells (macro-ovalocytes) in peripheral blood smears with immature erythroid cells, and megaloblasts in the bone marrow. It arises from asynchronous maturation of the nucleus and cytoplasm in blood cell precursors due to impaired DNA synthesis. While often caused by vitamin B12 or folate deficiency, rare causes include thymidine deficiency, inborn errors of metabolism, or drug-induced issues.
- Diagnosis involves a high index of suspicion, complete blood count with peripheral smear review, and bone marrow examination. While serum B12 and folate levels have limitations, assessment of serum homocysteine and methylmalonic acid is more sensitive and specific.
- Deficiencies in B12 or folate, common in developing countries due to nutritional deficits, can cause neurodevelopmental dysfunctions, hinder voluntary movement, and impair thriving.
- The anemia can mimic rheumatological malignancies like leukemia in children, highlighting diagnostic challenges. Features include pallor, anorexia, irritability, fatigue, and potentially hyperpigmentation of knuckles, hepatosplenomegaly, and hemorrhagic manifestations. Neurological symptoms can also manifest.
- Vitamin B12 is mainly absorbed in the distal ileum and is bound in the plasma azure protein transcobalamin. Deficiency, if caused by lack of intrinsic factor, can lead to juvenile pernicious anemia, which presents with a classic triad of progressive severe anemia, glossitis, and CNS signs (ataxia, paresthesia, and hypo/hyperreflexia).
- Folate, absorbed in the duodenum and jejunum, plays a crucial role in DNA/RNA synthesis and cell growth. Deficiency may result in neural tube defects during pregnancy. Anticonvulsants and oral contraceptives can induce folic acid deficiency.
- Treatment is generally highly effective with appropriate replacement therapy using cobalamin and/or folate. Oral B12 therapy shows promise, while pharmacological doses of folic acid require exclusion of B12 deficiency risks.
Exemple de certificat
À propos des intervenants
Dr Bharat Parmar
PROFESSEUR ET CHEF DU SERVICE DE PÉDIATRIE au Collège de MÉDECINE ZYDUS, Hôpital Civil.
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