New scoring system shows promise for assessing severity of ichthyosis


The researchers concluded that the system will be able to have a significant impact for both clinical and research use, enabling more accurate assessment of disease burden and better decision-making and monitoring.

The researchers created a scoring system that they say has proven to be reliable for measuring the severity of ichthyosis in adults and children.

In evaluating the validity of their Ichthyosis Scoring System (ISS), the researchers concluded that the system may have significant impact for both clinical and research use, allowing more accurate assessment of the burden of disease and enable better decision-making and follow-up.

“There have been attempts to assess scale thickness and erythema with various instruments, such as optical coherence tomography and reflectance spectroscopy, respectively. However, our goal was to design an instrument that could be used regardless of clinical resources in settings ranging from medical missions to academic centers,” the researchers described in their paper, also noting that no scale currently exists. which measures the severity of disease throughout the body. . “The medical treatment of patients with ichthyosis requires a systematic method to assess overall severity, but current grading systems offer limited use with respect to whole-body disease burden.”

Publish their findings in JAMA Dermatology, the researchers modeled their ISS based on the visual ichthyosis severity index—limited to 4 body parts—and the ichthyosis area severity index. Notable attributes of the new scale include:

  • Large-scale descriptors, which slows down to better reflect disease variability
  • Documentation of site-specific disease severity for parts of the body that significantly affect the patient’s perceived disease severity, including the face and palms
  • Recognition of a different scoring basis for children, who have different proportions of body regions than adults

The reliability of the scoring system, which divides the body into 10 regions, was determined using 2 groups of dermatologists: a group of 6 who had no training in ISS scoring and a group of 5 who have been formally trained.

Using 83 test photos of patients with ichthyosis among dermatologists, the system showed significant reliability, with the researchers highlighting the notoriety of the results due to the heterogeneity of the patients used in the photos. Interclass correlation coefficients (ICC) for total, scale, and erythema scores were 0.90, 0.91, and 0.88, respectively.

“Individual regions were assessed for both inter-rater and intra-rater correlations, ensuring that even individual scores could be used with accurate assessment,” the researchers noted. “Thickening and inflammation of the palms and soles can be debilitating for patients, and the palms and soles exhibit unique scaly morphology including yellow thickening, scaling scale, and fissures. Accordingly, these regions deserved their own set of scale descriptors and were included among the 10 sites.

Of the two groups of dermatologists, soles had the highest ICCs for the scale. Dermatologists had the most difficulty assessing the elbows and lower extremities, resulting in lower ICCs. According to the researchers, this could be due to the natural elbow wrinkles masking small adherent scales, especially in elderly patients, and the lower limbs having the largest surface areas, often with different scale severity.


Sun Q, Asch S, Bayart C, et al. Development and initial validation of a new system to assess the severity of ichthyosis. JAMA Dermatol. Published online February 16, 2022. doi:10.1001/jamadermatol.2021.5917


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