title: The epidemiology of childhood alopecia areata in China: a study of 226 patients.
abstract: To study the clinical and epidemiologic profile of childhood alopecia areata, we performed a survey in which a total of 226 childhood patients less than 16 years old were enrolled. Statistical analysis and heritability were performed using EPI INFO 6.0, SPSS10.0, and the Falconer method. The median age of onset was 10 years. The majority of patients (84.96%) presented with limited alopecia. The male : female ratio was 1.4:1. Boys appeared to have more severe involvement. The earlier the age of onset, the greater the severity of the disease. Sixty-seven patients (29.65%) had previous episodes of alopecia areata. Greater severity and longer duration were seen in the relapsing patients than in the primary patients. Six patients (2.65%) had an associated disease. A positive family history was reported in 25 patients (11.06%). The prevalence figures for alopecia areata in first-, second-, and third-degree relatives of the probands were 2.87%, 0.40%, and 0.13%, respectively. The heritabilities of AA in first-, second-, and third-degree relatives were 51.20%, 46.25%, and 25.65%, respectively. It can be speculated that the effect of genetic factors is important in the occurrence of this disease.
authors.affiliation: Insititute of Dermatology, Anhui Medical University and Key Laboratory of Genome Research Anhui, Hefei, China.
authors.forename: Feng-Li
authors.initials: FL
authors.lastname: Xiao
authors.forename: Sen
authors.initials: S
authors.lastname: Yang
authors.forename: Jiang-Bo
authors.initials: JB
authors.lastname: Liu
authors.forename: Ping-Ping
authors.initials: PP
authors.lastname: He
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.forename: Yong
authors.initials: Y
authors.lastname: Cui
authors.forename: Kai-Lin
authors.initials: KL
authors.lastname: Yan
authors.forename: Min
authors.initials: M
authors.lastname: Gao
authors.forename: Yan-Hua
authors.initials: YH
authors.lastname: Liang
authors.forename: Xue-Jun
authors.initials: XJ
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D017668:Age of Onset; D000506:Alopecia Areata / Q000175:diagnosis* / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D015995:Prevalence; D011379:Prognosis; D012720:Severity of Illness Index; D017678:Sex Distribution