P8.153 The Epidemiology of Androgentic Alopecia

Rod Sinclair, Desmond Gan

University of Melbourne Department of Dermatology, St Vincent’s Hospital

To explore the epidemiology of androgenetic alopecia (AGA), greying and seborrhoic dermatitis in the Australian community, questionnaires were sent to a 5000 adults aged 20 years and over selected at random. A subset of 397 subjects were then examined to assess the accuracy of the responses to the questionnaires.

The response rate of the questionnaires was 30.8%. The prevalence of AGA increased with advancing age. The age-adjusted prevalence was 45.7% (95% CI, 41.6% - 49.8%) in men, and 15.3% (95% CI, 12.4% - 18.2%) in women. In men, advanced AGA (Stage 4 and 5 of our scale) was uncommon until the 5^th decade. In women, Stage 1 hair density (of our scale) was most prevalent but decreased rapidly with age. Bitemporal recessive hairline was common in both sexes, but was less profound in women. In men, bitemporal recession was significantly correlated with age (p=0.07) and the severity AGA stages (p<0.01). No significant correlation was found in women.

The age- and sex- adjusted prevalence of grey hair was 76.1% (95% CI, 73.7% - 78.5%) and increased with advancing age. The age- and sex- adjusted frequency of subjects with history of seborrhoeic dermatitis was 42.8% (95% CI, 40.0% - 45.6%), affecting more males (age-adjusted frequency = 49.3%, 95% CI 45.2% - 53.4%) than females (age-adjusted frequency = 36.7%, 95% CI 32.9% - 40.5%).

An association was found between presence of bitemporal recessive hairline and history of seborrhoeic dermatitis in men (age-adjusted OR = 1.96, [1.07, 3.58], p=0.03). A strong and significant positive association existed between presence of grey hair and history of seborrhoeic dermatitis (age- and sex- adjusted OR = 3.18, [2.109, 4.793], p<0.01).

The prevalence and trend of AGA in the Australian community is similar to the Western community and is higher than the Asian community.