Anemia

Anemia is defined as a decrease in hemoglobin and/or hematocrit below normal values as defined by age and sex. The etiology of anemia in children varies by age, ranging from inadequate production of red blood cells (RBCs) to destruction of RBCs, or blood loss. Therefore, the differential diagnosis and workup should be based on age and clinical history. Although algorithms exist to help guide the differential based on mean corpuscular volume (MCV) and reticulocyte count, the focus of this section is to provide a brief overview of age-specific differential diagnoses to be considered when evaluating a patient for anemia. Note that if other blood cell lines (such as white blood cells or platelets) are affected, the differential could still include infection or medications, but should be broadened to include malignancy, bone-marrow failure syndrome, or both.

The basic workup for anemia should include a detailed history, physical exam, and complete blood count with differential and reticulocyte count.

Iron-Deficiency Anemia

Iron-deficiency anemia is the most common cause of anemia in children. The most common causes are lack of adequate dietary iron intake in infants and toddlers and blood loss from menstruation in adolescent females. It is uncommon for adolescent males with adequate dietary iron intake to present with iron deficiency; therefore, male teenage patients with iron deficiency should undergo a workup for occult blood loss.

Diagnosis of Iron-Deficiency Anemia

• History: Elicit factors contributing to poor dietary intake. Toddlers often have history of excessive milk intake (which can cause intestinal irritation leading to occult blood loss, decreased absorption of dietary iron, and/or decreased intake of other food items) or being a “picky” eater. Evaluate for symptoms of anemia including dizziness, fatigue, breathlessness, and palpitations.

• Physical examination to evaluate for signs of anemia (e.g., conjunctival pallor, tachycardia). Physical findings that should lead to further evaluation to rule out malignancy include lymphadenopathy and/or hepatosplenomegaly.

• Laboratory investigations: The following table depicts expected results in a patient with iron-deficiency anemia. Examination of peripheral smear will reveal microcytic, hypochromic red blood cells.

Treatment of Iron-Deficiency Anemia

The treatment of iron-deficiency anemia should be aimed at correcting the underlying cause (e.g., elimination of excessive milk intake in toddlers, treating menorrhagia in adolescent females). In addition, red-cell transfusions are indicated to correct symptomatic anemia.

• Oral iron therapy: Oral iron replacement should be given to all patients with a diagnosis of iron-deficiency anemia.

  • Counsel patients/parents about the side effects of oral iron therapy, including constipation and the potential need for laxatives.

  • Instruct parents not to administer iron within 1 to 2 hours of milk or other calcium-containing products because they reduce the absorption of iron.

• Intravenous iron therapy: Although it is rarely necessary to implement, a patient who is not able to take oral iron therapy successfully (nonadherence or unable to take iron due to taste or swallowing issues) is an indication for intravenous iron replacement. Intravenous iron carries the risk of infusion-related reactions, including anaphylaxis. Therefore, parents and patients should be counseled about possible adverse events.

(Source: Iron-Deficiency Anemia. N Engl J Med 2015.)