Pili annulati

{{Infobox medical condition (new) | name = Pili annulati | synonyms = | image = | caption = | pronounce = | field = | symptoms = | complications = | onset = | duration = | types = | causes = | risks = | diagnosis = | differential = | prevention = | treatment = | medication = | prognosis = | frequency = | deaths = Alternate names Ringed hair

Definition

Pili annulati is a hair disorder. In pili annulati, affected hair has a pattern of light and dark banding.

Epidemiology

• The prevalence of pili annulati is currently unknown.
• Since being first described in 1866, there are reports of approximatively 50 cases in the literature.

Cause

• A locus responsible for pili annulati was mapped on the end of the telomeric region of chromosome 12q (24.32–24.33), but the responsible gene for the disease is not yet completely identified.
• So far, a critical region of 2.9 Mb containing 36 candidates genes has been defined by recombination events.
• A report exists of a case of pili annulati associated with Rothmund-Thomson syndrome caused by a mutation in RECQL4.

Inheritance

Autosomal dominant pattern, a 50/50 chance.

• 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.

Signs and symptoms

• 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.
• It can be seen with the naked eye, however it may be more difficult to see in people with dark hair.

Diagnosis

• Light microscopy shows a characteristic appearance with alternating bright and dark bands in the hair shaft.
• Transmission electron microscopy of affected hairs shows a normal medulla with clusters of intermittent air-filled cavities within the cortex of the hair shafts.
• Scanning electron microscopy reveals a "cobblestoned" and fluted cuticle.
• Trichoscopy represents a simple and rapid method that enables the practitioners to establish the diagnosis of pili annulati without the need to pluck hairs.[1].

Treatment

• Treatment in pili annulati is often not required as it is a benign condition in which patients rarely seek medical attention.
• The shiny appearance of the hair is infrequently bothersome, and some patients even consider it attractive.
• There have been a few reports of a disappearance of the "ringed" appearance of the hair after daily use of topical minoxidil.
• In rare forms associated with hair breakage and fragility, gentle hair care is the recommendation.

Prognosis

Prognosis of pili annulati is excellent as it is a benign condition that doesn’t affect the quality of life of affected patients.