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Updated: Oct 1, 2026
Measuring Psoriasis Severity at Home
Published on: March 1, 2024
Histopathologic Characterization of Untreated and Treated Psoriasis: A Cross-Sectional Study
Terese Monette O Aquino1,2,3, Mary Grace Anne A Calvarido4,5,6, Claudine Joy M Ramos2,3
1Faculty of Medicine and Surgery, Department of Clinical Epidemiology, Dermatology, and Anatomy, University of Santo Tomas, Manila, Philippines.
Background:
The histopathological presentation of psoriasis may vary depending on the timing of the biopsy, prior treatments utilized, and the presence of secondary skin changes. Consequently, dermatopathologists play a pivotal role in ensuring an accurate diagnosis, particularly when the psoriatic histopathology deviates from the classic features. This study aims to compare the prevalence of classic and non-classic histopathologic features of psoriasis between untreated and treated psoriasis.
Methods:
This is a review of 109 biopsies of psoriasis from 2015 to 2021 obtained from a single institution. The cases were reviewed by two independent dermatopathologists who were blinded to the assigned groups (untreated, n = 62, and treated, n = 47). A 20-item histopathologic grading criterion, comprising both classic and non-classic features of psoriasis, was used for assessment.
Results:
The prevalence of both classic (p = 0.274; CI: -0.169, 0.593) and non-classic (p = 0.456; CI: -0.526, 0.236) histopathologic features of psoriasis did not differ between untreated (classic = 78%, non-classic = 27%) and treated (classic = 76%, non-classic = 29%) groups. A comparison of each histopathologic feature did not vary between groups (p > 0.05).
Conclusions:
Psoriasis is a dynamic condition under the microscope. Classic histopathologic features of psoriasis seem to persist despite treatment. Non-classic features may also occur regardless of the treatment status. Hence, the presence of these features should not preclude the tissue diagnosis of psoriasis.