Clinical manifestations of iron deficiency (independent of the presence of anemia). Alopecia occurs because hair follicle matrix cells are among the most rapidly dividing cells in the body (all rapidly growing cells require iron). Pica, the ingestion of non-nutritive materials reported in up to 55% of patients with iron deficiency. Atrophic glossitis is reported in about one-quarter of patients. Early atrophic glossitis is associated with reddening and enlargement of tongue papillae. Later changes include an atrophic, smooth, and beefy red appearance. In early stages of angular cheilitis (also called angular cheilosis and angular stomatitis), grayish white thickening with adjacent erythema may present at corners of mouth. In later stages, granulation tissue forms and adjacent skin often develops scaly dermatitis. Symptoms include soreness and pain. Restless legs occurs in reported in about 25% of patients with iron deficiency. Nail thinning and brittleness are common, while koilonychia (spoon-shaped finger nails) is rare. When koilonychia does occur, it primarily affects fingernails of first 3 digits. Cold intolerance occurs secondary to impaired temperature response from reduced efficacy of thyroid hormone (intracellular thyroid action is dependent on iron stores).
