Iron Deficiency Anemia

– A chronic anemia characterized by depleted iron stores and small, pale red blood cells lacking in hemoglobin.

Causes and Incidence

Iron deficiency anemia is usually caused by chronic blood loss or by an increased need for or decreased intake of iron. It is the most common of the anemias, with a high worldwide incidence. It occurs most often in women, children, and the elderly in underdeveloped countries.

Disease Process

Some factor (e.g., chronic blood loss, a decrease in iron intake) leads to iron deficiency. This occurs in orderly steps. Initially, iron loss exceeds intake, and the iron stores in the bone marrow are used and depleted. A compensatory mechanism increases absorption of dietary iron but depletion continues, and insufficient iron is available for RBC formation. This leads to a decrease in Hgb production, microcytosis, and a decrease in oxygenation of the tissues.

Symptoms

Usual signs and symptoms associated with anemia (pallor, fatigue, weakness) plus symptoms specific to the iron deficiency, such as glossitis, cheilosis, koilonychia (spoon-shaped fingernails), and pica.

Potential Complications

Exhaustion, infection, and respiratory and cardiac complications are possible if the condition goes untreated.

Diagnostic Tests

CBC
Decreased RBCs, Hgb, and Hct.

Peripheral blood smear
Decreased mean corpuscular volume and mean corpuscular Hgb concentration; microcytosis; hypochromia.

Iron capacities
Decreased serum iron, serum ferritin, and iron ferritin; increased iron-binding capacity.

Bone marrow aspiration
Erythrocyte: granulocyte ratio 1:1 (normal, 1:3-1:5); lack of marrow iron; ringed sideroblasts.

Treatments

Surgery – None.

Drugs – Iron replacement PO or parenterally.

General
Correction of underlying cause (e.g., treatment of bleeding, increased dietary intake of iron); nutritional education.

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