Relationship between skin color and cutaneous response to ultraviolet radiation in Thai

Abstract

Predictors of sensitivity to ultraviolet (UV) light, including Fitzpatrick's sun reactive skin types, constitutive skin color and facultative skin color were assessed in 43 healthy Thai volunteers. These predictors were compared with one another and with responses of the skin to UV irradiation, as determined by a minimal erythema dose (MED) of UVB, a minimal immediate pigment darkening dose (MIPDD) of UVA, and a minimal delayed tanning dose (MDTD) of UVA, and by dose‐response curves for erythema and pigmentation, as measured objectively with the use of a narrow‐band spectrophotometer. The skin type did not correspond well to the constitutive and facultative skin color. There was no correlation between skin type and MED and no relation between skin type and the slope of the dose‐response curves for erythema and pigmentation. Constitutional skin color was also not a good predictor of the measured MED, MIPDD and MDTD values but did appear to correlate with the steepness of the dose‐response curves for erythema but not for pigmentation. The facultative skin color, however, did not correlate with the dose‐response angle of erythema or pigmentation. We have thus found that the skin type is not a good predictor of UV responses in Thai. The constitutive skin color is a better predictor of UV responses of the skin than skin type and that steepness of dose‐response curves for erythema is a better measure of the response of the skin to UV irradiation than is a MED measurement.

Melanin differentially protects from the initiation and progression of threshold UV‐induced erythema depending on UV waveband

“…In contrast to a negative report in Thai subjects (7), our study showed that skin reflectance measurements of pigmentation are related to Fitzpatrick skin type, albeit with much overlap between skin types. The differences are possibly due to a lack of skin types I and II, and inclusion of subjects with skin type V in the Thai study.…”

Lack of correlation between minimal erythema dose and skin phototype in a colombian scholar population

“…Because we have found that colorimetry is a good predictor of MED in our population, we suggest that this method could replace the time‐consuming and laborious process to assess the MED before starting any phototherapeutic routine. Importantly, these results are in agreement with other studies that have reported a significant correlation of constitutive skin color with MED (22–29).…”

“…On the other hand, Leenutaphong (22) and Kawada (23) showed the limitations of the Fitzpatrick classification in individuals from Thailand and Japan, respectively. Unfortunately we could not perform a statistical comparison of MEDs in Caucasians because the number of subjects studied was not depicted in the reference cited.…”

Dermatologia na pele negra

“…Ele foi desenvolvido para definir a resposta de tipos diferentes de pele à luz ultravioleta solar, através de queimadura ou de bronzeamento. 1,5,6 Um sistema de classificação baseado na propensão da pele a se tornar hiperpigmentada por estímulo inflamatório e sustentar essa hiperpigmentação por período prolongado pode ser de valor, já que essa característica é exclusiva da pele pigmentada. 7 Ao longo deste texto estão implícitas, nas expressões "pele negra" e "indivíduo negro", as cores preta e parda.…”

“…1,6 Sugere-se que: não há diferença no número de glândulas sudoríparas écrinas, 1,22 embora se verifique mais sudorese em brancos; 1,23 as glândulas sudoríparas apócrinas são maiores, mais númerosas e produzem maior quantidade de secreção na pele negra; 1,24 há maior número de glândulas sudoríparas apócrino-écrinas na pele facial de mulheres negras; 1,14 não há diferença no número de glândulas sebáceas, mas essas são maiores e produzem maior quantidade de sebo na pele negra.…”