Pili Annulati

Pili annulati is a hair disorder. In pili annulati, affected hair has a pattern of light and dark banding. People with pili annulati may describe their hair as "striped" or as having silvery beads. Pili annulati typically involves 20-80% of scalp hair, however it can involve facial and body hair as well. Affected hairs may be more prone to breakage.  Pili annulati can present in infancy, childhood, or later in life. It can be seen with the naked eye, however it may be more difficult to see in people with dark hair. Diagnosis is confirmed by polariscopic and/or electron microscopic examination of affected hairs. The condition runs in an autosomal dominant fashion in some families. Reduced penetrance and variable expression has been described. Sporadic cases have also been reported.