Dermoscopy and UVFD in Differentiating Palmoplantar Psoriasis and Palmoplantar Eczema

Comparative Evaluation of Polarized Dermoscopy and Ultraviolet-Induced Fluorescence Dermoscopy in the Differential Diagnosis of Palmoplantar Psoriasis and Palmoplantar Eczema

Palmoplantar psoriasis and palmoplantar eczema are chronic inflammatory skin diseases that may show similar findings on the palms and soles, such as redness, scaling, thickening of the skin, fissures, itching, and burning. Because these conditions can look alike, distinguishing between them in routine clinical practice may be difficult.

This prospective, single-center observational study was designed to compare polarized dermoscopic and ultraviolet-induced fluorescence dermoscopic (UVFD) findings in adult patients with palmoplantar psoriasis and palmoplantar eczema. A total of 81 patients aged 18 years and older were included: 41 patients with clinically and/or histopathologically confirmed palmoplantar plaque psoriasis and 40 patients with palmoplantar eczema.

Dermoscopic and UVFD images were evaluated to identify vascular, scaling, surface, and fluorescence-related features that may help differentiate palmoplantar psoriasis from palmoplantar eczema. The study aims to assess whether these non-invasive imaging methods can provide additional diagnostic clues to support clinical evaluation.

Study Overview

• Status: Active, not recruiting
• Conditions: Eczema; Palmoplantar Psoriasis

Detailed Description

This prospective, single-center, observational comparative study was designed to evaluate polarized dermoscopic and ultraviolet-induced fluorescence dermoscopic (UVFD) findings in the differential diagnosis of palmoplantar psoriasis and palmoplantar eczema.

Adult patients aged 18 years and older with clinically and/or histopathologically confirmed palmoplantar plaque psoriasis or palmoplantar eczema were enrolled. Patients with recent topical or systemic treatment, positive fungal examination, palmoplantar pustulosis, other confounding palmoplantar dermatoses, malignancy or immunosuppressive conditions, pregnancy, lactation, non-specific histopathological findings, or histopathological findings inconsistent with the clinical diagnosis were excluded.

Demographic and clinical characteristics, lesion localization, symptom profile, relevant dermatological history, nail involvement, and disease severity parameters were recorded. Standardized polarized dermoscopic and UVFD images were obtained using a handheld dermoscope (DermLite DL5, 3Gen Inc., San Juan Capistrano, CA, USA). Imaging was performed under standardized conditions, and predefined dermoscopic and UVFD parameters relevant to inflammatory palmoplantar dermatoses were systematically evaluated.

In polarized dermoscopy, vascular morphology and distribution, scale color and distribution, background color, yellow-brown globules, yellow-orange structureless areas, yellow-orange crusts, and hemorrhage within scales were assessed. In UVFD, scale distribution, scale pattern, dominant fluorescence color, additional fluorescence color, and white-yellow fluorescent foci were evaluated. Image assessments were performed by independent dermatologists blinded to the clinical diagnosis.

The main objective of the study is to compare polarized dermoscopic and UVFD findings between palmoplantar psoriasis and palmoplantar eczema and to identify features that may support the clinical differentiation of these overlapping palmoplantar dermatoses. The study does not assign any treatment or intervention; all imaging procedures are non-invasive and performed for observational diagnostic evaluation.

• Study Type: Observational
• Enrollment (Actual): 81

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Istanbul
    • Istanbul, Istanbul, Turkey (Türkiye), 34000
      • Istanbul Training and Research Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

A total of 81 adult patients aged 18 years and older with clinically and/or histopathologically confirmed palmoplantar plaque psoriasis or palmoplantar eczema were included. Participants were recruited from the dermatology outpatient clinic of a tertiary care training and research hospital.

Description

Inclusion Criteria:

• Age 18 years or older.
• Clinical diagnosis of palmoplantar psoriasis or palmoplantar eczema involving the palms and/or soles.
• For the palmoplantar psoriasis group: presence of sharply demarcated erythematous and scaly plaques on the palms and/or soles, with diagnosis confirmed clinically and/or histopathologically.
• In clinically uncertain palmoplantar psoriasis cases, at least one supporting feature such as psoriatic lesions outside the palmoplantar area, psoriatic nail involvement, psoriatic arthritis, personal history of psoriasis, or family history of psoriasis.
• For the palmoplantar eczema group: presence of chronic or recurrent palmoplantar eczema with hyperkeratotic and/or fissured palmoplantar plaques, with diagnosis confirmed clinically and/or histopathologically.
• Ability and willingness to provide written informed consent.

Exclusion Criteria:

• Age younger than 18 years.
• Presence of another palmoplantar dermatosis that may interfere with the diagnosis of palmoplantar psoriasis or palmoplantar eczema.
• Histopathological findings inconsistent with the clinical diagnosis, when histopathological examination was performed.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Palmoplantar Psoriasis; Patients with clinically and/or histopathologically confirmed palmoplantar psoriasis
Palmoplantar Eczema; Patients with clinically and/or histopathologically confirmed palmoplantar eczema

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Participants With Findings on the Predefined Polarized Dermoscopic Feature Checklist Assessed Using DermLite DL5	Name of measurement: Predefined Polarized Dermoscopic Feature Checklist. Measurement tool: standardized polarized dermoscopic images obtained with a DermLite DL5 handheld dermoscope. Unit of measure: percentage of participants (%). Standardized polarized dermoscopic images will be assessed by blinded independent dermatologists using the checklist. The checklist includes vascular morphology, vascular distribution, scale color, scale distribution, background color, yellow-brown globules, yellow-orange structureless areas, yellow-orange crusts, and hemorrhage within scales. The percentage of participants with each finding will be reported separately for the palmoplantar psoriasis and palmoplantar eczema groups.	At baseline / single study visit
Percentage of Participants With Each Predefined Ultraviolet-Induced Fluorescence Dermoscopy Feature Assessed by DermLite DL5	Unit of measure: percentage of participants (%). Measurement tool: standardized ultraviolet-induced fluorescence dermoscopy (UVFD) images obtained with a DermLite DL5 handheld dermoscope and assessed by blinded independent dermatologists using a predefined UVFD feature checklist. The checklist includes UVFD scale distribution, UVFD scale pattern, dominant fluorescence color, additional fluorescence color, and white-yellow fluorescent foci. The percentage of participants with each feature will be reported and compared between the palmoplantar psoriasis and palmoplantar eczema groups.	At baseline / single study visit

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cohen's Kappa Coefficient for Interobserver Agreement in Binary and Nominal Dermoscopic and UVFD Feature Assessment	Name of measurement: Cohen's kappa coefficient for interobserver agreement. Measurement tool: blinded independent assessment of standardized polarized dermoscopic and ultraviolet fluorescence dermoscopic images using predefined feature checklists. Unit of measure: Cohen's kappa coefficient. Two blinded independent dermatologists will assess standardized images using predefined feature checklists. Cohen's kappa coefficient will be calculated separately for binary and nominal categorical checklist findings to evaluate interobserver agreement.	At baseline / single study visit
Quadratic Weighted Kappa Coefficient for Interobserver Agreement in Ordinal Dermoscopic and UVFD Feature Assessment	Name of measurement: quadratic weighted kappa coefficient for interobserver agreement. Measurement tool: blinded independent assessment of standardized polarized dermoscopic and ultraviolet fluorescence dermoscopic images using predefined feature checklists. Unit of measure: quadratic weighted kappa coefficient. Two blinded independent dermatologists will assess standardized images using predefined feature checklists. Quadratic weighted kappa coefficient will be calculated separately for ordinal checklist findings to evaluate interobserver agreement.	At baseline / single study visit

Collaborators and Investigators

• Sponsor: Istanbul Training and Research Hospital

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2025
• Primary Completion (Actual): April 20, 2026
• Study Completion (Estimated): July 31, 2026

Study Registration Dates

• First Submitted: May 8, 2026
• First Submitted That Met QC Criteria: May 29, 2026
• First Posted (Actual): June 4, 2026

Study Record Updates

• Last Update Posted (Actual): June 4, 2026
• Last Update Submitted That Met QC Criteria: May 29, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Dermoscopy; Differential diagnosis; Palmoplantar psoriasis; Palmoplantar eczema; Ultraviolet dermoscopy; UV dermoscopy
• Additional Relevant MeSH Terms: Skin Diseases; Skin Diseases, Eczematous; Dermatitis; Skin and Connective Tissue Diseases; Eczema
• Other Study ID Numbers: 2011-KAEK-50-263

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No