Luo Angela J, Arkin Lisa M, Asch Sarah, Benjamin Latanya, Bruckner Anna L, Cossio María Laura, Diaz Lucia, Lilly Evelyn, Mathes Erin F, Nelson Caroline A, Pope Elena, Ramachandran Sarika, Siegel Dawn H, Teng Joyce M C, Xu Yunshan, Deng Yanhong, Paller Amy S, Choate Keith A
Department of Dermatology, Yale School of Medicine, New Haven, Connecticut.
Department of Pediatric Dermatology, University of Wisconsin School of Medicine and Public Health, Madison.
JAMA Dermatol. 2025 Jul 9. doi: 10.1001/jamadermatol.2025.1965.
The Ichthyosis Scoring System (ISS) is a reliable instrument for assessing ichthyosis severity. The ISS's performance in individuals with skin of color (ie, Fitzpatrick IV-VI skin types) remains unknown because it was initially assessed in individuals with Fitzpatrick I to III skin types.
To assess the reliability of the ISS in individuals with Fitzpatrick IV to VI skin types.
DESIGN, SETTING, AND PARTICIPANTS: In this cross-sectional study, 14 dermatologists used the ISS to rate 94 test photographs, 47 from individuals with Fitzpatrick I to III skin types and 47 from individuals with Fitzpatrick IV to VI skin types. The professional photographs were obtained from the National Registry for Ichthyosis and Related Disorders, which enrolls participants with ichthyosis from referral centers, patient advocacy groups, and self-referral worldwide. Test photographs represented individuals of all phototypes with ichthyosis of all severities. Due to limited comprehensive, high-quality photography among individuals with Fitzpatrick IV to VI skin types, 4 body sites were chosen: upper back, legs, upper arm, and dorsal feet. From August to December 2023, dermatologists independently scored the same test photographs and were blinded to photographic groupings. Data were analyzed in March 2024.
Interrater reliabilities were determined using interrater intraclass correlation coefficients (ICCs) using the two-way random effects model.
Of the 61 individuals with ichthyosis represented in the 94 photographs, 28 (46%) were younger than 18 years and 33 (54%) were 18 years and older; 32 (52%) were female and 29 (48%) were male; and 1 (2%) was American Indian, 16 (26%) were Black, 6 (10%) were Hispanic, 1 (2%) was Pacific Islander, 5 (8%) were South Asian, 31 (51%) were White, and 1 (2%) was White and Hispanic. For individuals with Fitzpatrick I to III skin types, scale and erythema ICCs ranged from 0.97 (95% CI, 0.93-0.99) to 0.99 (95% CI, 0.98-1.00) and 0.91 (95% CI, 0.79-0.97) to 0.95 (95% CI, 0.89-0.99), respectively. For individuals with Fitzpatrick IV to VI skin types, scale and erythema ICCs ranged from 0.97 (95% CI, 0.93-0.99) to 0.99 (95% CI, 0.98-1.00) and 0.90 (95% CI, 0.80-0.96) to 0.94 (95% CI, 0.86-0.98), respectively. The overlap of ICC confidence intervals demonstrates ISS reliability across phototypes.
This cross-sectional study shows that the ISS can be applied across phototypes to measure ichthyosis severity. Further studies using full-body photographs would further bolster the ISS's reliability to assess global ichthyosis severity. These findings set the stage for increasing diversity in ichthyosis clinical trials.
鱼鳞病评分系统（ISS）是评估鱼鳞病严重程度的可靠工具。由于该系统最初是在菲茨帕特里克I至III型皮肤的个体中进行评估的，其在有色人种（即菲茨帕特里克IV - VI型皮肤类型）个体中的表现尚不清楚。
评估ISS在菲茨帕特里克IV至VI型皮肤个体中的可靠性。
设计、背景和参与者：在这项横断面研究中，14名皮肤科医生使用ISS对94张测试照片进行评分，其中47张来自菲茨帕特里克I至III型皮肤的个体，47张来自菲茨帕特里克IV至VI型皮肤的个体。专业照片来自鱼鳞病及相关疾病国家登记处，该登记处登记了来自全球转诊中心、患者倡导团体和自我推荐的鱼鳞病患者。测试照片代表了所有光型、所有严重程度的鱼鳞病个体。由于菲茨帕特里克IV至VI型皮肤个体中全面、高质量的照片有限，选择了4个身体部位：上背部、腿部、上臂和足背。2023年8月至12月，皮肤科医生独立对相同的测试照片进行评分，且对照片分组情况不知情。2024年3月对数据进行分析。
使用双向随机效应模型，通过组内相关系数（ICC）确定评分者间信度。
94张照片所代表的61例鱼鳞病患者中，28例（46%）年龄小于18岁，33例（54%）年龄在18岁及以上；32例（52%）为女性，29例（48%）为男性；1例（2%）为美洲印第安人，16例（26%）为黑人，6例（10%）为西班牙裔，1例（2%）为太平洋岛民，5例（8%）为南亚人，31例（51%）为白人，1例（2%）为白人和西班牙裔。对于菲茨帕特里克I至III型皮肤的个体，鳞屑和红斑的ICC范围分别为0.97（95%CI，0.93 - 0.99）至0.99（95%CI，0.98 - 1.00）和0.91（95%CI，0.79 - 0.97）至0.9
