Pili Annulati (Ringed Hair)

Pili annulati, also referred to as "ringed hair", is a genetically inherited condition (autosomal dominant) characterized by alternating dark and light bands in hairs especially in reflected light. It is caused by air filled cavities in a region of the hair known as the cortex. Increased hair fragility, leading to breakage, is reported in some patients. 20-80% of the hairs may be affected by the bands.