Pernicious anemia: Year of the Zebra

Pernicious anemia is an autoimmune disorder characterized by a decrease in the production of red blood cells due to lack of vitamin B12, an essential component for the development of red blood cells.

In pernicious anemia, a protein found in the stomach, called intrinsic factor, or IF, or the stomach cells that produce IF, are attacked by the immune system. Intrinsic factor normally binds to vitamin B12 to allow the vitamin to be absorbed through the gastrointestinal tract. When there is insufficient intrinsic factor, vitamin B12 cannot be absorbed, ultimately leading to a decrease in red blood cell production.

Now, the symptoms of pernicious anemia may include weakness, fatigue, abdominal discomfort after eating or drinking, palpitations, mouth ulcers, or even weight loss. Jaundice, or yellowing of the skin or sclera, can also occur. In more severe cases, symptoms can be due to damage to neurons and present as paresthesias, or ‘pins and needles’ sensations; spasticity, or abnormal muscle tone; and imbalance.

The diagnosis of pernicious anemia is based on the individual’s detailed medical history, and thorough clinical evaluation, however, blood tests are required to confirm the diagnosis. Blood tests can include a complete blood count, or CBC; vitamin B12 levels; peripheral smear; and antibody testing.