RESUMO
BACKGROUND: Androgenetic alopecia remains the most common cause of male pattern baldness (MPB) in all races. The prevalence of MPB in Caucasians is well documented. The prevalence of MPB in Asians is believed to be very low, only one-fourth to one-third on average compared to Caucasians. However, according to my previous study, there is a clear trend indicating that it is approaching that of Caucasians. OBJECTIVE: To assess the prevalence of MPB in the Asian population in Bangkok, Thailand; to compare this prevalence to previous studies conducted on Asians; and to compare the results to previous studies conducted on Caucasian. METHODS: This study was conducted by two physicians and assisted by two registered nurses. The questionnaire included age, sex, Norwood classification, diet, family history of baldness, income, and education. The physicians examined the scalp of each interviewee upon completion of each questionnaire. The ethnic focus group in this study was Thai and Chinese who reside in Bangkok, Thailand. The interviews were conducted in hospitals, nursing homes, classroom, medical meetings, temples, parks, and villages. RESULTS: A total of 1124 men were randomized in this study. The prevalence of cosmetically significant MPB (Norwood III-VII) was 38.52% and steadily increasing with age, approaching that of Caucasians. Variant MPB was found to be 0.67% and other types of androgenetic alopecia was 0.6%. From an ethnic point of view, the majority of the groups were of mixed blood and mostly of Chinese origin, thus we were unable to distinguish between Chinese and Thai. CONCLUSION: This study shows that the prevalence of MPB in Asians is not as low as previously thought. The cause of this increasing prevalence is uncertain. There are no past studies in Thailand for comparison, however, it can be extrapolated that the socioeconomic environment and westernized diet may contribute to this prevalence.
