Background/purpose: Facial skin hyperpigmention caused by chronic sun exposure is a major skin complaint, however, its characteristics and influential factors are still limitedly known.
Methods: A cross-sectional survey in healthy Japanese women aged from 6 to 62 years (n=169) was conducted using a facial image analyzer VISIA™ for knowing onset age of hyperpigmented spot formation, its chronological changes, and influence of environmental factors.
Results: UV Pigmented Spot (PS) Score was positively correlated with age (R=.487, P=.000). Hyperpigmented spots appeared first around 18 years old in most subjects, and PS score remarkably increased at 20s then gradually increased by ages. The subjects with Skin Type I, one of the three grades of Japanese Skin Type (JST), whose melanin formation is genetically lower, showed higher PS score. A woman aged 31 years was subjected a weekly VISIA measurement for 2 years, and found no changes in the number, place, size and intensity of the pigment spots in this duration.
Conclusion: Hyperpigmented spots developed in women over 20 years of age due to chronic sun exposure without sun protection during childhood and adolescent and it was stable afterwards, whose intensity was influenced by age and skin type.
Keywords: UV; hyperpigmentation; photo-aging; skin.
© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.