Overview
Definition:
Iron deficiency anemia (IDA) is a hematological disorder characterized by insufficient iron stores to meet the body's erythropoiesis needs, leading to a reduction in hemoglobin and red blood cell count
In children, it is the most common nutritional deficiency and cause of anemia.
Epidemiology:
IDA is a global health problem, particularly prevalent in developing countries
In India, the prevalence can be as high as 60-70% in certain age groups, with infants, toddlers, and adolescent girls being at highest risk
Risk factors include prematurity, low birth weight, exclusive breastfeeding beyond 4-6 months without iron supplementation, rapid growth spurts, inadequate dietary intake, chronic blood loss (e.g., from hookworm infestation or Meckel's diverticulum), and malabsorption syndromes.
Clinical Significance:
Untreated IDA in children can have serious long-term consequences, including impaired cognitive development, behavioral problems, reduced immune function, and poor growth
Early diagnosis and appropriate management are crucial to prevent irreversible damage and ensure optimal child development
Understanding precise dosing for oral and IV iron is vital for effective treatment in pediatric patients.
Clinical Presentation
Symptoms:
Pallor of skin and mucous membranes
Irritability and lethargy
Poor feeding and failure to thrive
Pica (craving for non-food substances like ice or dirt)
Delayed developmental milestones
Susceptibility to infections
Shortness of breath on exertion
Tachycardia
In severe cases: koilonychia (spoon-shaped nails) and angular stomatitis.
Signs:
Generalized pallor
Mild icterus may be present in severe cases due to ineffective erythropoiesis
Tachycardia
A functional systolic murmur may be heard due to hyperdynamic circulation
Hepatosplenomegaly can occur in chronic severe anemia
Examination of nails may reveal koilonychia
Check for signs of underlying causes like intestinal parasites or gastrointestinal bleeding.
Diagnostic Criteria:
Diagnosis is confirmed by a combination of clinical suspicion and laboratory findings
Typically, a hemoglobin level below the age-specific normal range
Microcytic hypochromic red blood cells (low MCV and MCH) on peripheral smear
Low serum ferritin is the most sensitive and specific indicator of iron deficiency
Other confirmatory tests include low serum iron, elevated total iron-binding capacity (TIBC) or transferrin, and low transferrin saturation.
Diagnostic Approach
History Taking:
Detailed dietary history focusing on iron-rich foods, milk intake, and introduction of solids
History of prematurity, low birth weight, or any perinatal complications
Previous blood transfusions or diagnosed anemias
Symptoms suggestive of chronic blood loss (e.g., melena, hematochezia, frequent vomiting) or malabsorption (e.g., chronic diarrhea, abdominal pain)
Family history of anemia or bleeding disorders
For adolescent girls, menstrual history is important.
Physical Examination:
Thorough physical examination including assessment of pallor (conjunctivae, palmar creases), vital signs, cardiovascular system (murmurs, tachycardia), abdominal examination (organomegaly), neurological assessment (developmental milestones), and examination of skin and nails (pica, koilonychia).
Investigations:
Complete Blood Count (CBC): Hemoglobin, Hematocrit, MCV, MCH, MCHC, RDW
Peripheral Blood Smear: Microcytosis, hypochromia, anisopoikilocytosis, target cells, elliptocytes
Iron Studies: Serum Ferritin (gold standard), Serum Iron, TIBC, Transferrin Saturation
Reticulocyte Count: Usually low or normal in IDA, increases with treatment
Other tests may include stool examination for occult blood or parasites, and investigations for malabsorption if suspected.
Differential Diagnosis:
Other causes of microcytic anemia: Thalassemia trait (normal or elevated iron studies), Anemia of Chronic Disease (low serum iron, normal or low TIBC, normal or low ferritin), Sideroblastic anemia (iron overload, ring sideroblasts on bone marrow), Lead poisoning (basophilic stippling)
Distinguishing features include iron studies, response to iron therapy, and family history.
Management
Oral Iron Dosing:
Elemental iron dosage: 3-6 mg/kg/day, divided into 1-3 doses
Maximum dose usually 65 mg of elemental iron per day for infants and young children, and up to 180-200 mg/day for older children and adolescents
Duration: Continue for 3 months after hemoglobin normalization to replete iron stores
Oral iron is best absorbed on an empty stomach, but may be given with food if gastrointestinal upset occurs
Vitamin C enhances absorption.
Iv Iron Indications:
Indications for IV iron: Severe anemia where rapid correction is needed
Intolerance or unresponsiveness to oral iron therapy
Significant gastrointestinal blood loss or malabsorption
Conditions requiring iron infusion include inflammatory bowel disease, chronic kidney disease, post-gastric surgery, and severe chronic anemia in infants where oral iron is not tolerated or effective
Pre-operative iron loading in children undergoing major surgery with expected blood loss.
Iv Iron Dosing And Administration:
Dosing is based on the degree of anemia and iron deficit, often calculated using the formula: Total Iron to be administered (mg) = Body Weight (kg) x (Target Hb - Actual Hb) x 1.5 (for Hb in g/dL) + Iron Stores (e.g., 500-1000 mg for adults, adjusted for children)
Common IV iron preparations include iron sucrose, ferric carboxymaltose, and iron dextran
Infusion rates and dilution vary by product and patient age/condition
Careful monitoring for hypersensitivity reactions is essential
Pediatric-specific IV iron dosing charts are available and should be consulted.
Nutritional Counseling:
Education on iron-rich foods such as fortified cereals, green leafy vegetables, lentils, and meat
Advise avoiding excessive milk intake, especially with meals, as calcium can inhibit iron absorption
Reinforce the importance of continuing iron supplementation for the prescribed duration.
Complications
Complications Of Ida:
Cognitive and developmental delays
Behavioral abnormalities
Impaired immune function leading to increased infections
Poor physical growth and development
Chronic fatigue and reduced quality of life.
Complications Of Oral Iron:
Gastrointestinal side effects are common: nausea, vomiting, abdominal pain, constipation, diarrhea, and dark stools
These can lead to poor compliance
Staining of teeth can occur with liquid preparations.
Complications Of Iv Iron:
Hypersensitivity reactions (anaphylaxis, especially with older iron dextran formulations)
Local reactions at the infusion site (pain, phlebitis)
Transient fever, chills, arthralgias, myalgias
Hypotension
Iron overload is rare with appropriate dosing but possible with repeated infusions
Long-term complications are related to the underlying cause of anemia.
Prognosis
Factors Affecting Prognosis:
Severity and duration of anemia
Age of diagnosis and initiation of treatment
Presence of co-morbidities
Adherence to treatment
Responsiveness to iron therapy
Underlying cause of iron deficiency.
Outcomes:
With timely and appropriate treatment, the prognosis for iron deficiency anemia in children is excellent
Hemoglobin levels typically begin to rise within a week of starting iron therapy, and normal levels are usually achieved within 1-2 months
However, long-term cognitive and developmental sequelae may persist if anemia was severe and prolonged, especially in early childhood.
Follow Up:
Regular follow-up is essential to monitor treatment response (hemoglobin, ferritin levels) and compliance
Duration of treatment is typically 3-6 months, with a repeat hemoglobin check 1 month after stopping iron
For children with ongoing risk factors for iron deficiency, long-term monitoring and preventive strategies are crucial
Investigate and treat the underlying cause of iron deficiency to prevent recurrence.
Key Points
Exam Focus:
Most common nutritional deficiency in children
Microcytic hypochromic anemia
Low serum ferritin is diagnostic
Oral iron is first-line
IV iron for intolerance, severe anemia, or malabsorption
Dose of oral iron: 3-6 mg/kg/day elemental iron
Duration: 3 months post-Hb normalization.
Clinical Pearls:
Always consider iron deficiency in any child with microcytic anemia
Counsel parents on dietary sources and adherence
Use a chewable or liquid form for younger children, but caution about teeth staining
IV iron calculations need to account for both Hb deficit and iron stores for optimal replection.
Common Mistakes:
Diagnosing IDA based solely on low hemoglobin without confirming iron deficiency with ferritin
Inadequate duration of oral iron therapy, leading to relapse
Using inappropriate IV iron doses or failing to monitor for hypersensitivity reactions
Not investigating the underlying cause of IDA, leading to recurrence.