Close-up of a smooth tongue in a person suffering from pernicious anaemia as a complication of Addison's disease. The condition of the tongue is affected in a number of blood disorders. Mild anaemias or deficiencies of iron, folate or vitamin B12 may lead to a sore, inflamed tongue or mouth. Pernicious anaemia is a form of anaemia (a reduction in oxygen-carrying haemoglobin in the blood) resulting from vitamin B12 deficiency. The smooth appearance of this tongue is due to a loss of papillae (the projections associated with the taste buds). Pernicious anaemia is associated with other auto-immune" diseases in addition to Addison's disease."