Ichthyosis Score Reliable in Skin of Color

TOPLINE:

In a cross-sectional study, the Ichthyosis Scoring System (ISS) demonstrated equal reliability in assessing scale and erythema severity across all skin types, with excellent interrater reliability for both light and dark skin tones.

METHODOLOGY:

• To address the reliability of the ISS in individuals with skin of color, researchers conducted a cross-sectional study that involved 14 dermatologists rating 94 photographs from 61 individuals from the National Registry for Ichthyosis and Related Disorders between August and December 2023.
• Of the 94 photographs, 47 were of individuals with Fitzpatrick I-III skin types (57% Women; 89% White, 6% Hispanic, and 3% South Asian individuals) and 47 were of individuals with Fitzpatrick IV-VI skin types (46% Women; 62% Black, 15% Hispanic, and 15% South Asian individuals).
• Dermatologists used the ISS to score photographs from the upper back, legs, upper arm, and dorsal feet for scale and erythema severity.

TAKEAWAY:

• The mean scale score was 2.49 for individuals with Fitzpatrick I-III skin types and 2.50 for those with Fitzpatrick IV-VI skin types (P < .86). The mean erythema scores were 1.94 and 1.88 in the two groups, respectively (P < .32).
• ISS scale scoring showed excellent interrater reliability (0.97-0.99) in both skin type groups.
• Erythema scoring demonstrated good to excellent reliability in III-IV skin types (0.90-0.94) and excellent reliability in I-III skin types (0.91-0.95).
• Overlapping CIs confirmed consistency between skin types.

IN PRACTICE:

“This study supports the ISS as a reliable scoring instrument for ichthyosis severity across phototypes, providing a foundation for increasing diversity in clinical trials,” the study authors wrote. “ISS’s accessibility, ease of use, broad applicability, and robust reliability underscore its role as the standard ichthyosis severity scoring tool,” they added. “The development and validation of tools like the Ichthyosis Scoring System, and ensuring that it is applicable to measure clinical outcomes in patients of all skin tones, is an essential step in providing equitable clinical care to all patients,” a JAMA Dermatology editorial fellow and associate editor wrote in an accompanying commentary.

SOURCE:

This study was led by Angela J. Luo, BA, Department of Dermatology, Yale School of Medicine, New Haven, Connecticut, and was published online on July 9 in JAMA Dermatology.

LIMITATIONS:

Due to limited availability of comprehensive, high-quality photography among individuals with Fitzpatrick IV-VI skin types, researchers could only validate the ISS across four body sites: upper back, legs, upper arm, and dorsal feet. The authors noted that additional studies using full-body photographs would be beneficial to further validate the ISS’s reliability for assessing global ichthyosis severity. Objective erythema measurements were not used.

DISCLOSURES:

Luo was funded by the Richard K. Gershon Endowed Medical Student Research Fellowship and the Yale School of Medicine Fellowship for Medical Student Research. Several authors reported receiving personal fees, advisory fees, grants, and other support from AbbVie, Eli Lilly, Incyte, Janssen, Sanofi, and various other drug companies.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.