An epidemiological survey of skin damage on the dorsal hand in rural populations in northern and southern China.

To determine the extent of and the contributing factors in skin ageing in the Chinese population, we collected data on 691 participants in northern (high latitude region) and southern China (low latitude region). The skin damage of the participants was graded according to a Beagley-Gibson scoring system based on photographs of the dorsal hand skin. The results revealed that age was an important contributing factor for skin damage. In both regions, the mean skin damage grade increased with age. The mean skin damage grade for the subjects in the low latitude region was significantly higher than that for those in the high latitude region in all of the age groups (P<0.05). There was nearly a 10-year delay before the high latitude region subjects achieved the same degree of hand skin damage as the low latitude region subjects. Lifetime sun exposure was another independent factor that influenced the degree of skin damage. As age increased, the difference in the lifetime sun exposure between the two regions increased, but the difference in the extent of skin damage decreased. Skin damage on the hand may be more affected by sun exposure early in life. Furthermore, female sex and a higher body mass index (i.e., ⩾24.0) were associated with a lower skin damage grade (adjusted odds ratio [AOR] 0.54, 95% CI 0.40-0.73 and AOR 0.40, 95% CI 0.25-0.65, respectively). Compared with the subjects who lived at high latitude, those who lived at low latitude had an increased risk of a higher score (5.22; 95% CI, 3.68-7.42).