Abstract
Pernicious anemia (also known as Biermer's disease) is an autoimmune atrophic gastritis, predominantly of the fundus, and is responsible for a deficiency in vitamin B12 (cobalamin) due to its malabsorption. Its prevalence is 0.1% in the general population and 1.9% in subjects over the age of 60 years. Pernicious anemia represents 20%-50% of the causes of vitamin B12 deficiency in adults. Given its polymorphism and broad spectrum of clinical manifestations, pernicious anemia is a great pretender. Its diagnosis must therefore be evoked and considered in the presence of neurological and hematological manifestations of undetermined origin. Biologically, it is characterized by the presence of anti-intrinsic factor antibodies. Treatment is based on the administration of parenteral vitamin B12, although other routes of administration (eg, oral) are currently under study. In the present update, these various aspects are discussed with special emphasis on data of interest to the clinician.