In vivo time-sequential histological study focused on melanocytes: suggestion of golden time for intervention to prevent post-laser pigmentary changes

Awareness of sun exposure risks and photoprotection for preventing pigmentary disorders in Asian populations: Survey results from three Asian countries and expert panel recommendations

BACKGROUND

In this article, we review and discuss the photoprotection behavior of Asians based on the literature, along with a subanalysis of an original online survey, and make recommendations to optimize photoprotection for Asian populations to prevent photoaging and pigmentary disorders.

METHODS

An international panel of eight dermatologists from Asia (China, Korea, Japan, Singapore, Indonesia, and Vietnam) met to discuss sunscreen photoprotection for Asian patients. Additionally, a subanalysis of an online survey by 3000 respondents from three Asian countries (China, Indonesia, and Japan) investigated general public awareness and attitudes to sun exposure.

RESULTS

A pre-meeting survey of the eight experts from Asia showed key concerns of Asian patients consulting dermatologists are pigmentary disorders, especially actinic/senile lentigo, post-inflammatory hyperpigmentation, melasma, vitiligo, and Hori's nevus. The survey subanalysis of participants from China, Indonesia, and Japan with predominantly Fitzpatrick skin types (FST) II to IV revealed that they are particularly concerned about sun exposure causing photoaging and pigmentary disorders. Most of the respondents indicated they have limited knowledge on sunlight radiation and appropriate sunscreen protection factors. Only 22%, 13%, and 3% for China, Indonesia, and Japan, respectively, systematically use multiple protective measures (using sunscreen, avoiding midday sun, staying in the shade, wearing a hat, protective clothing, and sunglasses) when exposed to the sun.

CONCLUSIONS

Further education is needed for Asian populations on the importance of comprehensive daily photoprotection, including broad-spectrum sunscreen, with high UVA and visible light protection, to reduce and prevent photoaging and pigmentary disorders.

Commentary: Facial Aesthetic Dermatological Procedures and Photoprotection in Chinese Populations

The medical literature on aesthetic dermatology has primarily focused on a light-skinned patient population, yet patients of darker skin types have different needs and priorities. In Chinese individuals, key concerns include altered pigmentation, which is perceived to age the individual, and also relates to the Chinese cultural standard of beauty of fair skin; many seek aesthetic treatment for this. Non-invasive cosmetic procedures such as lasers and injections are also gaining in popularity in the Chinese market, but this population is prone to hyperpigmentation as an adverse effect of such procedures. Considered and tailored approaches, both to primary concerns of photoaging and the side effects of cosmetic treatments, are warranted.

Photoprotection according to skin phototype and dermatoses: practical recommendations from an expert panel

Increasing evidence on the impact of the different wavelengths of sunlight on the skin demonstrates the need for tailored recommendations of sunscreen according to skin phototype and dermatoses, which is now possible due to advances in the filters and formulations of sunscreens. A selective literature search was performed by an international expert panel, focusing on the type of sunscreen to recommend for photoaging, skin cancers, photodermatoses, pigmentary disorders and skin inflammatory disorders. Protection against ultraviolet (UV)B is especially important for light skin as there is a high risk of sunburn, DNA damage and skin cancers. Darker skin may be naturally better protected against UVB but is more prone to hyperpigmentation induced by visible light (VL) and UVA. Protection against UVA, VL and infrared A can be helpful for all skin phototypes as they penetrate deeply and cause photoaging. Long‐wave UVA1 plays a critical role in pigmentation, photoaging, skin cancer, DNA damage and photodermatoses. Adapting the formulation and texture of the sunscreen to the type of skin and dermatoses is also essential. Practical recommendations on the type of sunscreen to prescribe are provided to support the clinician in daily practice.

[Post-inflammatory hyperpigmentation occuring after cosmetic procedures]

A post-inflammatory hyperpigmentation (PIHP) can occur after cosmetic procedures such as chemical peels and lasers. Patients must be informed about this risk. Precautionary measures before, during and after the procedure can prevent or reduce the risk of PIHP. These procedures should not be done in summer on suntanned skin and patients have to be aware of the importance of an effective photoprotection. The PIHP occurs more frequently on dark-skinned patients, in Asians as well as in women with melasma history. In these cases, risk/benefit assessment of the cosmetic procedure is required: no risky procedure in patients at risk! PIHP can also be related to technical errors such as too high concentration or too long exposure time during peel procedure as well as excessive threshold fluences during laser procedure. If many therapies for PIHP damages can be proposed, patients feel frequently that they are not as quickly effective as they would like. Patients must be reassured as many PIHP resolve spontaneously. If photoprotection is always required, it is also possible to accelerate the pigmentation's clearing using the Kligman trio or the numerous topical lightening agents targeting several steps of the hyperpigmentation process. More invasive and expensive therapies such as peels, lasers, IPL or radiofrequency might be used for refractory cases. As a pigmentary relapse might occur after these procedures, the traditional Kligman trio should be always considered.