[Structural and ultrastructural study of an isolated case of pili annulati]

A case of pili annulati in an eighteen year old woman is described. The hairs show bright spots along hair shafts when viewed in daylight. The transmission and scanning electron microscopy confirmed that the bright spots are due to small cavities into the cortex. The plasmatic measurement of copper, zinc and of the most important hormone, such as the dosage of plasmatic, urinary and hair aminoacids, allowed the Authors to exclude any influence of metabolic systemic alterations on the pathogenesis of pili annulati. Neither cutaneous nor internal anomalies were detected.