Serum Ferritin Levels: A Clinical Guide in Patients With Hair Loss.

Ferritin is a key regulator of iron homeostasis that serves as an important clinical indicator of body iron status. Low serum ferritin is a highly specific and sensitive marker for diagnosing iron deficiency. In patients presenting with diffuse hair loss, serum ferritin may be a clinically useful tool for ruling out underlying iron deficiency as a cause of alopecia. As an acute-phase reactant, ferritin may be nonspecifically elevated in a wide range of inflammatory conditions; however, the role of ferritin in disorders of the skin and hair is not well understood. In this article, we review the structure and function of ferritin, and we provide a guide for clinical use.