Identification of factors associated with minimal erythema dose variations in a large‐scale population study of 22 146 subjects

Abstract

Background Minimal erythema dose (MED) has substantial inter‐ and intraindividual variations, reflecting the influence of very diverse factors. However, related studies showed little consistency probably because of their limited sample size. Objective To identify the factors associated with MED variations in a large‐scale population study. Methods The MED test was performed by following the international standard procedure on 22 146 subjects. The results were analysed in adjusted multivariable linear and logistic regression models. Results This large‐scale study revealed that lower MED was consistently associated with lighter skin [β‐coefficient = −0.33, 95% confidence interval ( CI ) −0.36 to 0.30, P = 6.41 × 10 −84 ]. Females had significantly higher MED than male (β = 0.91, 0.32–1.50, P = 2.93 × 10 −3 ). Stratified analyses showed that MED was not associated with age [female: odds ratio ( OR ) = 0.99, 0.98–1.01; male: OR = 0.99, 0.97–1.00]. MED was lower in summer than in other seasons (spring: OR = 1.08, 1.06–1.11; autumn: OR = 1.11, 1.08–1.13; winter: OR = 1.20, 1.18–1.22). Furthermore, MED was associated with air temperature (β = −0.36, −0.49 to 0.23, P = 4.81 × 10 −8 ) and air pressure (β = −0.64, −0.82 to 0.46, P = 8.01 × 10 −12 ) in summer only while not in other seasons. Conclusions This study provides unprecedented evidence that MED is associated with skin colour, sex, season and meteorological factors, but not with age.

Validation of a novel method of ultraviolet-induced cutaneous inflammation and its associations with anhedonia

“…First, associations between PI-MED erythema and most potential covariates were not fully consistent with previous findings. For example, while previous research has not found an association between age and www.nature.com/scientificreports/ MED, a distinct but related measure to PI-MED erythema 71,82 , the current study found a significant negative association between age and PI-MED erythema. Future work should seek to firmly establish how age may be related to erythema response.…”

Chinese women with melasma exhibit a low minimal erythema dose to both UVA and UVB

“…We recruited Chinese women with and without melasma from age twenty to sixty at our dermatology clinic at the First Affiliated Hospital of Kunming Medical University from 2020 to 2021. As many variables, including age, skin color, sex, skin test sites, and meteorological factors, can influence MED measurements, 9 the age and sites tested were comparably recruited between the subjects of melasma and normal control groups. The diagnosis of melasma was established according to international diagnostic criteria by Pandya et al 10 All subjects provided basic demographic and clinical information.…”

Commentary: Facial Aesthetic Dermatological Procedures and Photoprotection in Chinese Populations

“…In the same population, Liu et al measured minimal erythema dose (MED) and minimal persistent pigmentation dose (MPPD), which correlated with skin type: from type II to IV, MED increased gradually, while the MPPD decreased slightly [1]. Tan et al also found, in a large-scale population study of more than 20,000 Han Chinese individuals from Shanghai, that lighter skin [based on individual typology angle (ITA)] was consistently associated with lower MED [5].…”