Pemphigus oral lesions area index (POLAI): A new scoring scale for assessing oral pemphigus vulgaris.

Objectives: Current scales for Pemphigus vulgaris (PV) do not adequately represent the clinical variability of oral lesions. This study aimed to develop an independent scale, the Pemphigus Oral Lesions Area Index (POLAI), for assessment of oral PV exclusively, and compare POLAI, Pemphigus Disease Area Index (PDAI), Autoimmune Bullous Skin Disorder Intensity Score (ABSIS) and Oral Disease Severity Score (ODSS) regarding inter- and intra-observer reliability and validity.

Materials and methods: Retrospective cohort included 209 sets of digital-photographs. Additional clinical cohort included 32 PV patients. All visits were assessed by four clinicians using the PDAI, ABSIS, ODSS and POLAI, and were rated by three specialists using the Physician's Global Assessment (PGA).

Results: The intraclass correlation coefficient showed the inter-observer reliability with 0.89 and 0.86 for PDAI, 0.87 for ABSIS, 0.93 for ODSS, 0.96 for POLAI, and 0.97 and 0.96 for PGA. Intra-observer agreements showed excellent reliability for all 4 scores. Highest correlation was observed between PGA and POLAI (correlation coefficients were 0.96). The mean time taken to complete each scale was within 1.5 min.

Conclusion: POLAI is valid for the assessment of oral PV with superior inter- and intra-observer reliability to PDAI, ABSIS and ODSS, and is feasible in clinic.