Iron Deficiency Anemia: An Updated Review

Worldwide, iron deficiency anemia is the most prevalent nutritional deficiency disorder and the leading cause of anemia in children, especially in developing countries. When present in early childhood, especially if severe and prolonged, iron deficiency anemia can result in neurodevelopmental and cognitive deficits, which may not always be fully reversible even following the correction of iron deficiency anemia.

This article aimed to familiarize physicians with the clinical manifestations, diagnosis, evaluation, prevention, and management of children with iron deficiency anemia.

A PubMed search was conducted in February 2023 in Clinical Queries using the key term "iron deficiency anemia". The search strategy included all clinical trials (including open trials, non-randomized controlled trials, and randomized controlled trials), observational studies (including case reports and case series), and reviews (including narrative reviews, clinical guidelines, and meta-analyses) published within the past 10 years. Google, UpToDate, and Wikipedia were also searched to enrich the review. Only papers published in the English literature were included in this review. The information retrieved from the search was used in the compilation of the present article.

Iron deficiency anemia is most common among children aged nine months to three years and during adolescence. Iron deficiency anemia can result from increased demand for iron, inadequate iron intake, decreased iron absorption (malabsorption), increased blood loss, and rarely, defective plasma iron transport. Most children with mild iron deficiency anemia are asymptomatic. Pallor is the most frequent presenting feature. In mild to moderate iron deficiency anemia, poor appetite, fatigability, lassitude, lethargy, exercise intolerance, irritability, and dizziness may be seen. In severe iron deficiency anemia, tachycardia, shortness of breath, diaphoresis, and poor capillary refilling may occur. When present in early childhood, especially if severe and prolonged, iron deficiency anemia can result in neurodevelopmental and cognitive deficits, which may not always be fully reversible even with the correction of iron deficiency anemia. A low hemoglobin and a peripheral blood film showing hypochromia, microcytosis, and marked anisocytosis, should arouse suspicion of iron deficiency anemia. A low serum ferritin level may confirm the diagnosis. Oral iron therapy is the first-line treatment for iron deficiency anemia. This can be achieved by oral administration of one of the ferrous preparations, which is the most cost-effective medication for the treatment of iron deficiency anemia. The optimal response can be achieved with a dosage of 3 to 6 mg/kg of elemental iron per day. Parenteral iron therapy or red blood cell transfusion is usually not necessary.

In spite of a decline in prevalence, iron deficiency anemia remains a common cause of anemia in young children and adolescents, especially in developing countries; hence, its prevention is important. Primary prevention can be achieved by supplementary iron or iron fortification of staple foods. The importance of dietary counseling and nutritional education cannot be overemphasized. Secondary prevention involves screening for, diagnosing, and treating iron deficiency anemia. The American Academy of Pediatrics recommends universal laboratory screening for iron deficiency anemia at approximately one year of age for healthy children. Assessment of risk factors associated with iron deficiency anemia should be performed at this time. Selective laboratory screening should be performed at any age when risk factors for iron deficiency anemia have been identified.