Dermoscopy vs. histopathology in palmoplantar psoriasis and hyperkeratotic eczema: a cross-sectional study

Hyperkeratotic palmoplantar lesions (HPPLs), primarily encompassing palmoplantar psoriasis (PPP) and hyperkeratotic palmoplantar eczema (HPKE), present a significant diagnostic challenge due to overlapping clinical morphological features. This study evaluates the diagnostic accuracy of dermoscopy as a non-invasive bridge between clinical evaluation and standard histopathology.

An observational cross-sectional study was conducted on 44 adult patients presenting with clinically diagnosed HPPLs at a tertiary care center over an 18-month period. Patients underwent thorough clinical examination, dermoscopic evaluation (using a DermLite DL200 Hybrid), and a standard 4.0 mm punch biopsy for histopathological confirmation. Inter-method agreement and diagnostic concordance among the three modalities were analyzed using Cohen's kappa statistic.

The study cohort (mean age 40.32 years) was histopathologically confirmed to have psoriasis in 31 cases (70.45%) and eczema in 11 cases (25%). Dermoscopically, regularly distributed red dots and globules strongly indicated psoriasis (45.16% vs. 0% in eczema), whereas irregular vascular patterns predominated in eczema (54.55%). Concordance between dermoscopic and histopathological diagnoses was remarkably high, showing good agreement (81.81% concordance, κ = 0.652, p < 0.0001). Conversely, clinical-histopathological agreement was poor (56.82%, κ = 0.041), and clinical-dermoscopic agreement was fair (65.90%, κ = 0.350).

The findings of dermoscopy align closely with histopathology. Dermoscopy serves as an effective adjunctive tool to minimize reliance on invasive skin biopsies, rather than completely replacing them.