Microcytic anemia

Microcytic anemia
Classification and external resources
ICD-10	D50.8

Microcytic anemia (BrE: anaemia) is a generic term for any type of anemia characterized by small red blood cells. The normal mean corpuscular volume (abbreviated to MCV on full blood count results) is 76-100 fL, with smaller cells (<76 fL) described as microcytic and larger cells (>100 fL) as macrocytic.

In microcytic anemia, the red blood cells (erythrocytes) are usually also hypochromic, meaning that the red blood cells are paler than usual. This can be quantified as the mean corpuscular hemoglobin or mean cell hemoglobin (MCH), the amount of hemoglobin per cell; the normal value is 27-32 picograms (pg). Similar is the mean corpuscular hemoglobin concentration (MCHC), giving the amount of hemoglobin per volume of erythrocytes (normally about 320-360 g/L or 32-36 g/dL). Typically, therefore, anemia of this category is described as "microcytic, hypochromic anemia".

Causes

Typical causes of microcytic anemia include:

• childhood
  • iron deficiency anemia, by far the most common cause of anemia in general and of microcytic anemia in particular
  • thalassemia
• adulthood
  • iron deficiency anemia
  • sideroblastic anemia, congenital or acquired
  • Warm antibody autoimmune hemolytic anemia
  • Hereditary spherocytosis
  • anemia of chronic disease , although this more typically causes normochromic, normocytic anemia. Microcytic anemia has been discussed by Weng et al.
  • lead poisoning (rare)
  • pyridoxine deficiency

Other causes that are "typically" thought of as causing normocytic anemia or macrocytic anemia must also be considered, and the presence of two or more causes of anemia can distort the "typical" picture of each.

The Mentzer index is one tool used to identify the cause of microcytic anemias.

See also

• Hypochromic anemia

External links

• Emedicine on chronic anemia
• FP Notebook
• American Family Physician
• Overview (vet)