Frequency of the Types of Alopecia at Twenty-Two Specialist Hair Clinics: A Multicenter Study.

Background: The frequency of different types of alopecia is not clearly reported in recent studies.

Objective: To analyze the frequency of the types of alopecia in patients consulting at specialist hair clinics (SHC) and to assess for global variations.

Methods: Multicenter retrospective study including data from patients evaluated at referral SHC in Europe, America, Africa and Australia.