Publications, References, and Further Reading
The evidence for automated CLASI rests on two literatures: the validation of the CLASI instrument itself, and the peer-reviewed measurement methods behind the device's component models. This page collects both. How they combine, and what remains to be validated in CLE specifically, is discussed on the Clinical evidence page.
The CLASI instrument
Development and reliability. Albrecht J, Taylor L, Berlin JA, et al. The CLASI (Cutaneous Lupus Erythematosus Disease Area and Severity Index): an outcome instrument for cutaneous lupus erythematosus. Journal of Investigative Dermatology. 2005;125(5):889-894. PubMed
The original instrument. Introduced the separation of a reversible activity score (erythema, scale/hypertrophy, mucosal involvement, hair loss) from a cumulative damage score (dyspigmentation, scarring), with content validity assessed by a dermato-rheumatology panel and inter- and intra-rater reliability estimated on real patients.
Responsiveness and severity strata. Klein R, Moghadam-Kia S, LoMonico J, et al. Development of the CLASI as a tool to measure disease severity and responsiveness to therapy in cutaneous lupus erythematosus. Archives of Dermatology. 2011;147(2):203-208. PubMed
Established the activity severity strata used throughout these pages (mild 0–9, moderate 10–20, severe 21–70) and found that a clinically meaningful response corresponds to roughly a 4-point or 20% fall in the CLASI activity score.
Reliability across specialties and ages. Reliability and validity of the CLASI in paediatric cutaneous lupus, among paediatric dermatologists and rheumatologists. British Journal of Dermatology. 2019;180(1):165. Journal
Narrative review. Chakka S, et al. The CLASI, a validated tool for the evaluation of skin disease in lupus erythematosus: a narrative review. Annals of Translational Medicine. Journal
Contemporary context. Severity Scores for Cutaneous Lupus Erythematosus. Journal of Investigative Dermatology. Journal
The CLA-IGA-R instrument
Origin of the CLA-IGA. Gaffney RG, Werth VP, Merola JF. Cutaneous lupus erythematosus disease assessment: highlighting CLE outcome measures. Frontiers in Medicine. 2022;9:968469. PubMed
Describes the original CLA-IGA, developed by dermato-rheumatology experts through an international consensus exercise because no CLE-specific investigator's global assessment existed. It graded erythema, scale, edema or infiltration, follicular plugging and secondary change together on a single 0–4 scale.
Inter- and intra-rater reliability. Merola JF, Zhang AJ, Childs BA, et al. Inter-rater and intra-rater reliability of the Cutaneous Lupus Activity-Investigator Global Assessment-Revised (CLA-IGA-R) instrument. Journal of Investigative Dermatology. 2025;145(8):2085-2088.e2. PubMed
The revised investigator's global assessment, which scores erythema, other morphologic characteristics and follicular activity as three separate items on a 0–4 scale. Reliability was reported for the erythema and other morphologic characteristics items, on cases spanning all Fitzpatrick skin types.
Content validity. Merola JF, Yang W, Li Q, et al. Cutaneous Lupus Activity Investigator's Global Assessment-Revised (CLA-IGA-R) content validity: cutaneous lupus erythematosus patient qualitative study. ACR Convergence 2025. Abstract
Interviews with patients with CLE, supporting that the signs patients experience are captured by the three items.
Place in the core outcome set. Zhang AJ, Perez-Chada LM, Werth VP, Merola JF. Expert consensus achieved on a working core outcome set for cutaneous lupus erythematosus research in survey following the 5th International Conference on Cutaneous Lupus Erythematosus (ICCLE). Lupus Science & Medicine. 2024;11(1):e001165. PubMed
An international panel of CLE experts endorsed CLASI and the CLA-IGA-R together as the investigator-assessed measures of disease activity, with the CLA-IGA-R placed as a secondary or exploratory endpoint complementary to CLASI while its validation continues.
Erythema grading across subtypes and skin of colour. Xie L, Faden DF, Stone CJ, et al. Subtype and racial erythema variation for cutaneous lupus trials. JAMA Dermatology. 2025;161(1):67-74. PubMed
Mean CLASI erythema was mapped onto pink and red categories as a surrogate for CLA-IGA erythema scores. Among patients meeting typical CLASI entry criteria, erythema in Black patients was more often graded pink than red, so an eligibility criterion requiring red lesions at baseline would disproportionately exclude them. The authors recommend CLASI for erythema eligibility, a point that bears on any colour-based measurement in a phototype-diverse population.
The methods behind our CLASI components
The device measures the individual signs CLASI is built from, using models published in the indications they were developed for. None is CLE-specific, which is the boundary set out on the Clinical evidence page, but each documents the underlying measurement method and its reliability.
- Erythema, scale and induration are the intensity signs behind automated PASI and the acne composite; see the acne and psoriasis publications, including the peer-reviewed ALADIN work.
- Lesion detection and counting methodology is shared with the automated IHS4; see the hidradenitis suppurativa clinical evidence.
- Image quality is governed by DIQA (Dermatology Image Quality Assessment); see the DIQA validation.
Regulatory and quality context
The device is CE-marked and built on an ISO 13485-certified quality management system, with performance claims maintained in the technical documentation rather than asserted on these pages. The Compliance and security page covers the framework.