New scoring system demonstrates reliability in live evaluation of ichthyosis severity

Key takeaways:

• The Ichthyosis Scoring System was developed to quantify ichthyosis severity across body sites.
• The system demonstrated excellent and good reliability in scoring scaling and erythema severity, respectively.

The Ichthyosis Scoring System demonstrated robust reliability for both in-person and photographic scoring of ichthyosis severity, according to a study.

“Ichthyoses are a heterogeneous group of skin disorders with varying degrees of scaling and erythema,” Caroline Echeandia-Francis, BA, of the department of dermatology at Yale University School of Medicine, and colleagues wrote. “There is significant regional variation by body site within individuals and across genotypes. Since these are rare disorders, clinicians may not have experience in assessing disease burden, and there is a need for validated indices to evaluate severity over time.”

To quantify severity for this complicated disease, the authors developed the Ichthyosis Scoring System (ISS). Previous studies found that the ISS was successful in quantifying severity from photographs of the disease; however, the authors wanted to determine if the ISS would be able to replicate these results with live patients.

To do this, the researchers conducted a study where a group of nine dermatologists and pediatricians trained in ichthyosis used the ISS to evaluate 65 patients. Intrarater and interrater intraclass correlation coefficients (ICC) were used to score the model’s success.

Results showed that intrarater reliability for live use was excellent for scaling (ICC = 0.931; 95% CI, 0.921-0.94) and good for erythema scoring (ICC = 0.876; 95% CI, 0.853-0.899). These results were comparable with the ISS’s performance in evaluating scaling (ICC = 0.956; 95% CI, 0.925-0.974) and erythema (ICC = 0.913; 95% CI, 0.855-0.949) with photographs.

While the ISS demonstrated excellent interrater reliability for live use over 10 body sites for scale (ICC > 0.9) and good reliability for erythema (ICC > 0.75), it showed only moderate interrater agreement and consistency for erythema evaluation of the palms (ICC > 0.5).

“This study demonstrates robust reliability for both in-person and photographic ISS scoring,” the authors concluded. “Accessibility, ease of use, efficiency and content validity support the ISS as the clinical and research standard for ichthyosis severity analysis.”