Clinical-pathological diagnostic concordance in inflammatory dermatoses: a single-center retrospective analysis

PURPOSE: Inflammatory dermatoses are a heterogeneous group with overlapping clinical presentations, often requiring histopathological confirmation. The concordance between clinical impression and pathological diagnosis remains understudied in routine practice. MATERIALS AND METHODS: We retrospectively analyzed 150 patients who underwent skin biopsy for suspected inflammatory dermatoses between 2020 and 2025. Two concordance definitions were prespecified: primary-impression concordance (agreement between the primary clinical diagnosis and pathological category) and any-differential concordance (presence of the pathological category among any listed pre-biopsy differentials). Diagnostic performance metrics with 95% confidence intervals were calculated by disease category. Logistic regression incorporating disease category identified predictors of primary-impression accuracy. RESULTS: Primary-impression concordance was 64.0% and any-differential concordance 96.0%, yielding a 32-percentage-point gap indicating that clinicians frequently considered the correct diagnosis without selecting it as the primary impression. Agreement between primary clinical diagnosis and pathology was fair (kappa = 0.394). Primary-impression sensitivity was highest for lichen planus (90.9%) and psoriasis (79.8%), and substantially lower for mycosis fungoides (33.3%) and dermatitis/eczema (15.8%). Any-differential sensitivity reached 100.0% for mycosis fungoides and 73.7% for dermatitis/eczema, indicating these diagnoses were routinely considered but seldom prioritized. Disease category was the dominant independent predictor of primary-impression accuracy; the number of differential diagnoses was not significant after adjustment. CONCLUSIONS: Clinical diagnosis of inflammatory dermatoses shows variable accuracy across disease entities. Dermatologists demonstrate broad diagnostic reasoning but commit to the correct primary impression less often. Histopathological examination remains essential, particularly for dermatitis/eczema and early mycosis fungoides.