Early-onset androgenetic alopecia in China: a descriptive study of a large outpatient cohort

Abstract

Objective: To describe the clinical features of early-onset androgenetic alopecia (AGA) in a large cohort of Chinese patients.

Methods: This descriptive study recruited consecutive patients seeking medical treatment for AGA between 1 January 2013 and 30 November 2018. Patients were included in the study if they reported being ≤35 years old at AGA onset and if their pattern of hair loss was documented with photographs. The age of onset, sex, body mass index (BMI), BAsic and SPecific classification of hair loss and family history of alopecia were collected in an electronic database.

Results: A total of 3897 patients with early-onset AGA were recruited to the study. The majority of patients (70.6%; 2751 of 3897) were 21–30 years old and male (72.7%; 2834 of 3897). No association was found between high BMI (≥25 kg/m²) and early-onset AGA. There were significantly more overweight male AGA patients than overweight female patients (86.8% [632 of 728] versus 13.2% [96 of 728], respectively). The overall prevalence of familial AGA was 72.8% (2837 of 3897) and the condition was inherited more often from the father (52.8%; 1498 of 2837) than from the mother (24.3%; 688 of 2837).

Conclusions: Early-onset AGA primarily affects male patients between 21–30 years of age. Males with early-onset AGA are likely to have inherited AGA from their fathers.

Keywords: Androgenetic alopecia; age distribution; early onset; family history.

Figure 1.

Anatomical regions of the scalp (a). The BAsic and SPecific classification systems (b). Four BAsic types (L, M, C and U) and two SPecific types (frontal [F] and vertex [V]). L, no recession is observed in the frontotemporal region; M, recession in the frontotemporal hairline is more obvious than the mid-anterior hairline; C, recession in the mid-anterior hairline is more obvious than the frontotemporal hairline; U, the anterior hairline recedes to the vertex forming a horseshoe shape.^,

Figure 2.

Dermoscopic photographs showing representative images of the different stages and severities of androgenetic alopecia used in this current study.

Figure 3.

Age distribution of patients with early-onset androgenetic alopecia (a). Comparison of the sex of patients with early-onset androgenetic alopecia according to the age distribution (b).

Figure 4.

Body mass index (BMI) of male and female patients (n = 3685) with early-onset androgenetic alopecia.

Figure 5.

Distribution of patients according to their family history of androgenetic alopecia (a). Comparison between the sexes of a positive family history of androgenetic alopecia (b).