Pernicious Anemia (Nursing)

Pernicious anemia (PA) is a type of megaloblastic anemia. Megaloblastic anemia occurs due to vitamin B12 (cobalamin) deficiency. Vitamin B12 deficiency can occur via many mechanisms, but in PA, this occurs due to a lack of intrinsic factor (IF). Intrinsic factor is a glycoprotein that binds cobalamin and therefore enables its absorption at the terminal ileum. Pernicious anemia is an autoimmune disorder that occurs due to autoantibodies directed against IF or gastric parietal cells (that produce IF). These antibodies lead to the destruction of gastric parietal cells or prevent the absorption of vitamin B12 by blocking IF binding sites for this vitamin. As a result, vitamin B12 cannot be absorbed from the alimentary canal, and vitamin B12-associated megaloblastic anemia occurs. The clinical presentation of pernicious anemia is multifarious and insidious in onset. Symptoms may include fatigue, pallor, paresthesia, dyspepsia, depression, impaired memory, and even psychosis. Any number or combination of these symptoms may be present in patients with this disease, which causes a diagnostic dilemma. The diagnosis is also problematic secondary to imperfect diagnostic tools. The treatment of PA consists of life-long replacement of vitamin B12, usually via intramuscular injections. When the disease remains undiagnosed and untreated for an extended period, it may lead to neurological complications, gastric cancer, and even fatal anemia.