Skin-in-Sight: a Longitudinal Cohort Infrastructure for Standardized Remote Monitoring and the Evaluation of Digital Care Innovations in Chronic Skin Diseases (Skin-in-Sight)

Psoriasis, atopic dermatitis (eczema) and hidradenitis suppurativa are long-term skin conditions that flare and settle over time. Most of what happens to the skin happens at home, between hospital appointments. A dermatologist usually sees the skin only on the day of the visit, which may not reflect how the condition has been over the preceding months.

This study sets up a long-term research collection, called a cohort, in which people with one of these three conditions take part from home. Once a month, participants use a certified digital health app on their own phone to answer a short set of questions about their symptoms and about how their skin affects daily life, and to take a standard set of photographs of their skin. Twice a year they answer a longer set of questions. Taking part takes about five minutes in most months and about twenty-five minutes twice a year. The app gives step-by-step guidance on lighting, distance and framing at the start of every photo session, so that the photographs can be compared from month to month.

The photographs are reviewed by trained assessors, who score how severe the skin disease looks using the scoring systems established in dermatology research. Three assessors score each set of photographs independently, and their scores are combined according to rules that are set in advance. With the participant's permission, this information is combined with information already recorded during routine care, such as changes in treatment and hospital visits; with pharmacy records showing which medicines were dispensed; and with publicly available daily measurements of air quality, sunshine, ultraviolet radiation and pollen for the area where the participant lives.

Bringing these together makes it possible to study how these conditions change over time, what happens in the period before a flare, and how treatment and the living environment relate to the course of the disease. The collected data are also intended to support the development of computer-based tools that could in future help assess skin disease from photographs.

Taking part does not change the care a participant receives. The study does not provide medical advice, and the data collected are not used for diagnosis, treatment decisions or routine follow-up. Participants who experience worsening symptoms contact their treating physician as usual.

The cohort is also designed so that studies of digital care tools can later be carried out within it, among participants who have agreed in advance to be approached. Each of those studies is registered separately.

Study Overview

• Status: Not yet recruiting
• Conditions: Psoriasis; Hidradenitis Suppurativa (HS); Eczema/Atopic Dermatitis

Detailed Description

Rationale. Chronic inflammatory skin diseases follow a fluctuating course, and the determinants of that course largely operate outside the clinical encounter: treatment adherence, self-management capacity, and environmental exposure to air pollution, ultraviolet radiation and pollen. These determinants are held in separate information systems and are rarely assembled for the same patient over time. Routine care records disease activity only at the moments a patient attends, and validated severity instruments such as PASI and EASI, although recommended by guidelines, are applied inconsistently in practice. Remote photographic follow-up is a plausible way to close this gap, but patient-acquired photographs vary considerably in quality, and only a modest proportion are judged clearly sufficient for clinical decision-making. This cohort therefore combines a standardized home photography procedure with a pre-specified, multiple-rater scoring procedure, and links the resulting measurements to routine care data, national pharmacy dispensing data and daily environmental exposure data.

Objectives. The primary objectives are: (1) to establish a longitudinal cohort infrastructure for patients with chronic inflammatory skin diseases that permits the embedding and evaluation of multiple randomized digital care interventions using a cohort multiple randomized controlled trial design; (2) to prospectively collect standardized longitudinal data comprising serial home photographs, patient-reported outcome measures, and clinically relevant disease outcomes derived from routine care; and (3) to create a dataset suitable for the development, training and validation of models for automated or semi-automated assessment of disease severity and disease impact from photographs and patient-reported measures.

The secondary objectives are: to describe disease trajectories over time, including patterns of stability and flare; to evaluate current dermatological care pathways by comparing outcomes and healthcare use between digitally supported and standard outpatient follow-up; to explore factors associated with disease worsening; to assess the feasibility, completeness and adherence of long-term home-based photograph and questionnaire collection in routine care; and to quantify the reliability of photograph-based severity scoring across raters of differing professional background, including the effect of access to the clinical record on scoring consistency.

Design and setting. Prospective observational cohort at two hospital dermatology departments in the Netherlands, designed as reusable research infrastructure. No intervention is assigned at cohort level; participants receive usual care. Participants are informed by their treating physician during a routine outpatient visit, contacted subsequently by the research team, given a reflection period of at least one week, and included after electronic informed consent.

Measurement schedule. Participants complete a baseline questionnaire set and a baseline photograph set at inclusion. Thereafter a fixed monthly schedule applies, at approximately day 28, identical for every participant and deliberately not responsive to symptom worsening. Each monthly session comprises a short questionnaire set and a standardized home photograph set; an extended questionnaire set is added twice yearly. Automated reminders are sent after two days and after one week, with research team contact where needed.

Photograph acquisition. Standardization is achieved through disease-specific written photo protocols and in-app capture guidance on lighting, background, distance, framing and flash, presented at the start of every session. No automated image quality algorithm is applied at the point of capture. For psoriasis and atopic dermatitis, each session begins with a question about currently visible facial disease, followed by three standardized facial photographs where applicable, and by trunk, arm and leg photographs from every participant at every session. For hidradenitis suppurativa the session proceeds region by region (axillae, groin, gluteal, inframammary, perineal or genital, and other), with a presence question and, where lesions are present, counts of nodules, abscesses and draining tunnels; photography of each region is offered but optional. For every region the dataset records one of three states: photographed and scored, reported as affected but not photographed, or reported as clear, so that an absent photograph is not interpreted as absent disease.

Photograph scoring. Before cohort initiation, all personnel involved in scoring, including dermatologists, clinician-researchers and trained medical students, complete a calibration session against a reference set of annotated photographs, covering the instruments applicable to their assigned disease group. Each submitted photograph set is scored independently by three calibrated raters, at least two of whom score from the photographs alone without access to the participant's clinical record at the time of scoring. Rater assignments and scoring timestamps are recorded. Where image quality prevents assessment, the affected components are recorded as missing and the reason documented in one of six predefined categories: blur or motion artefact; insufficient or uneven lighting; incorrect framing or distance; incomplete coverage of the affected area; identifiable features visible outside the consented scope; and other. Consensus is the mean of the three scores for continuous instruments and the median for ordinal staging. Sets exceeding the pre-specified discordance threshold are referred to an adjudicating rater, either the principal investigator or a designated senior dermatologist not involved in the original scoring of that set, whose score replaces the consensus label. All submitted photographs are retained regardless of assessed quality; the accumulated quality annotations are intended to serve as labelled training data for the future development of automated image quality assessment tools, which do not presently exist within the study.

Linked data. Disease exacerbations, healthcare use, care setting and associated costs are derived from routine electronic health records and hospital procedural codes. Dispensing data are obtained from the national pharmacy information system. Environmental exposures are treated as exposure variables rather than outcomes and are linked to each participant by residential postal code and measurement date: air quality parameters from the national Luchtmeetnet network operated by RIVM, using the monitoring station nearest the residential postal code or, where no station lies within a defined distance, modelled national concentration grids; daily sunshine duration, global radiation, ambient temperature and ultraviolet index from the national meteorological institute, using the automatic weather station closest to the participating sites; and daily tree and grass pollen concentrations from the two national reference stations. No pollen monitoring station is located in the study region, so pollen exposure is approximated from national reference stations and modelled estimates; this is acknowledged as a limitation in pollen-related analyses.

Participant characteristics. Participant characteristics are recorded at inclusion and updated at least annually. These comprise demographics (age, sex, height, weight, body mass index, family situation, educational level, employment status), clinical background and lifestyle (smoking status, allergies, comorbidities and their treatment, current medication use), environmental and exposure-related factors (childhood and current residency, pets, Fitzpatrick skin type based on self-reported burning and tanning response), and disease-related variables (diagnosis, disease duration, baseline severity), together with disease-specific characteristics such as atopic comorbidity. These variables are used descriptively and as covariates; they are not outcome measures.

Analysis. Repeated measurements within individuals are analysed using linear mixed-effects models for continuous measures and appropriate generalized models for count and binary measures. Associations between environmental exposures and disease activity are explored using time-series and mixed-effects approaches, including lagged exposures where relevant; these analyses are exploratory. Because all participants share a single regional exposure series for several parameters, between-person contrasts in environmental exposure are limited and inference rests mainly on within-person temporal variation. Agreement between raters is quantified using intraclass correlation coefficients for continuous instruments and weighted kappa for ordinal staging, reported per disease population and, where numbers permit, per rater group. Participants who leave the study are compared with those who remain, using their last available measurements, to characterize any systematic differences; all participants contribute data up to the point of leaving.

Sample size. No formal sample size calculation is performed at cohort level. The cohort is an infrastructure intended to support multiple analyses and embedded evaluations rather than a single predefined comparison, and the anticipated enrollment reflects feasibility and representativeness of the population treated at the participating departments. Sample size calculations for embedded interventions are performed separately and described in the corresponding intervention protocols.

Cohort evaluation. A formal evaluation is conducted every two years from the date of first inclusion, by the principal investigator, the coordinating investigator, a paediatrician, an epidemiologist and a patient panel representative. It covers participant experience, data quality and completeness, attrition, progress of embedded evaluations, and continued scientific and clinical justification. Targets are pre-specified for this evaluation, assessed overall and per disease group, with photograph-related targets assessed separately for hidradenitis suppurativa given that photography is optional in that group: at least 70% average monthly questionnaire completion, at least 70% average monthly photograph set submission, at least 65% of submitted photograph sets of sufficient quality to be scored, at least 75% of quality-passed sets scored by all three raters within 90 days, no more than 20% annual attrition among active participants, and a minimum of 30 active participants per disease group at the first evaluation and 50 thereafter. These are pre-specified operational targets for the evaluation, not hypotheses and not predictions; failure to meet a target triggers a documented action plan and, for attrition, may lead to stopping or substantially modifying that part of the study.

Embedded evaluations. Randomized evaluations of digital care components may be embedded using a cohort multiple randomized controlled trial design, in which eligible participants are randomly selected and invited, with outcomes compared against eligible participants not selected. The present record concerns the cohort infrastructure only. Each embedded intervention is submitted as a separate ethics application and registered as a separate interventional study referencing this record.

Data retention. Research data are retained for a minimum of 15 years.

• Study Type: Observational
• Enrollment (Estimated): 1000

Contacts and Locations

• Study Contact: Name: Bram de Kinderen, MSc; Phone Number: +31 6 11172886; Email: bram.dekinderen@mst.nl
• Study Contact Backup: Name: Tanja Vogel, PhD; Email: t.vogel@mst.nl

Study Locations

• Netherlands
  • Overijssel
    • Almelo, Overijssel, Netherlands, 7609PP
      • Ziekenhuisgroep Twente
      • Contact: Bram de Kinderen, MSc; Phone Number: +31 6 11172886; Email: b.dkinderen@zgt.nl
    • Enschede, Overijssel, Netherlands, 7512KZ
      • Medisch Spectrum Twente
      • Contact: Bram de Kinderen, MSc; Phone Number: +31 6 11172886; Email: bram.dekinderen@mst.nl
      • Principal Investigator: Tanja Vogel, PhD
      • Sub-Investigator: Bram de Kinderen, MSc
    • Hengelo, Overijssel, Netherlands, 7555 DL
      • Ziekenhuisgroep Twente
      • Contact: Bram de Kinderen, MSc; Phone Number: +31 6 11172886; Email: b.dkinderen@zgt.nl
      • Principal Investigator: Bram de Kinderen, MSc

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

The study population consists of patients of above 16 years old with a chronic inflammatory skin disease who are under treatment at the dermatology department of MST or ZGT at the time of inclusion.

Eligible patients are informed about the study during a routine outpatient visit at the dermatology department. Participation is voluntary, and informed consent is obtained prior to inclusion, via the app.

Description

Inclusion Criteria:

• Diagnosis of a chronic inflammatory skin disease (psoriasis, atopic dermatitis, hidradenitis suppurativa), as determined by the treating dermatologist.
• Currently receiving dermatological care at Medisch Spectrum Twente (MST) or Ziekenhuisgroep Twente (ZGT) at the time of inclusion.
• Willing and able to participate in longitudinal monitoring, including completion of questionnaires and submission of standardized photographs.
• Sufficient command of the Dutch language to understand the study information and to complete questionnaires.

Exclusion Criteria:

• The patient has insufficient command of the Dutch language resulting in the insufficient ability to understand and/or answer questions

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort
Psoriasis; All patients with psoriasis
Eczema; All patients with eczema/atopic dermatitis
Hidradenitis suppurativa; All patients with hidradenitis suppurativa

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Establish a longitudinal cohort infrastructure	To establish a longitudinal cohort infrastructure for patients with chronic inflammatory skin diseases (psoriasis, atopic dermatitis, hidradenitis suppurativa) that enables the embedding and evaluation of multiple randomized digital care interventions using a cohort multiple randomized controlled trial (cmRCT) design.	10 years
Psoriasis Area and Severity Index (PASI) derived from patient-acquired photographs	Consensus PASI score, defined as the mean of three independent scores assigned by calibrated raters from the monthly home photograph set. Psoriasis Area and Severity Index: minimum 0, maximum 72; higher scores indicate more severe disease. Assessed in participants with psoriasis.	Monthly, from enrollment up to 10 years
Eczema Area and Severity Index (EASI) derived from patient-acquired photographs	Consensus EASI score, defined as the mean of three independent scores assigned by calibrated raters from the monthly home photograph set. Eczema Area and Severity Index: minimum 0, maximum 72; higher scores indicate more severe disease. Assessed in participants with atopic dermatitis.	Monthly, from enrollment up to 10 years
International Hidradenitis Suppurativa Severity Score System (IHS4) derived from patient-acquired photographs	Consensus IHS4 score, defined as the mean of three independent scores assigned by calibrated raters from the monthly home photograph set. International Hidradenitis Suppurativa Severity Score System: weighted count of nodules, abscesses and draining tunnels; minimum 0, no predefined maximum; higher scores indicate more severe disease. Because photography of sensitive regions is optional, the photograph-derived score is interpreted as a lower bound where affected regions were not photographed. Assessed in participants with hidradenitis suppurativa.	Monthly, from enrollment up to 10 years
Refined Hurley stage derived from patient-acquired photographs	Consensus refined Hurley stage, defined as the median of three independent stages assigned by calibrated raters from the monthly home photograph set. Refined Hurley classification: ordinal stages [TO CONFIRM: exact level set to be registered, i.e. I-III or IA-IIIB]; higher stages indicate more severe disease. Assessed in participants with hidradenitis suppurativa.	Monthly, from enrollment up to 10 years
Dermatology Life Quality Index (DLQI) total score	Dermatology Life Quality Index, a 10-item patient-reported questionnaire on the impact of skin disease on daily life. Minimum 0, maximum 30; higher scores indicate greater impairment of quality of life.	Monthly, from enrollment up to 10 years
Numeric Rating Scale for itch, average intensity	Patient-reported average itch intensity over the preceding period, recorded on a Numeric Rating Scale. Minimum 0 (no itch), maximum 10 (worst imaginable itch); higher scores indicate more severe symptoms. Assessed in participants with psoriasis or atopic dermatitis.	Monthly, from enrollment up to 10 years
Numeric Rating Scale for itch, peak intensity	Patient-reported worst itch intensity over the preceding period, recorded on a Numeric Rating Scale. Minimum 0 (no itch), maximum 10 (worst imaginable itch); higher scores indicate more severe symptoms. Assessed in participants with psoriasis or atopic dermatitis.	Monthly, from enrollment up to 10 years
Numeric Rating Scale for pain, average intensity	Patient-reported average pain intensity over the preceding period, recorded on a Numeric Rating Scale. Minimum 0 (no pain), maximum 10 (worst imaginable pain); higher scores indicate more severe symptoms. Assessed in participants with hidradenitis suppurativa.	Monthly, from enrollment up to 10 years
Numeric Rating Scale for pain, peak intensity	Patient-reported worst pain intensity over the preceding period, recorded on a Numeric Rating Scale. Minimum 0 (no pain), maximum 10 (worst imaginable pain); higher scores indicate more severe symptoms. Assessed in participants with hidradenitis suppurativa.	Monthly, from enrollment up to 10 years
AI modelling	To create a high-quality dataset that can be used for the development, training and validation of AI models for automated or semi-automated assessment of disease severity and disease impact based on photographs and PROMs.	10 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Disease trajectories	To describe disease trajectories over time in patients with chronic inflammatory skin diseases, including patterns of stability and flares as observed through longitudinal photo and PROM monitoring.	10 years
Risk factors	To explore factors associated with disease worsening or flares, including patient characteristics, clinical variables and patient-reported signals, and to relate these factors to clinically relevant outcomes such as treatment escalation or unscheduled care.	10 years
Assess feasibility	To assess the feasibility, data completeness and patient adherence of long-term home-based photo and PROM collection in routine dermatology care.	10 years
Skindex-29 symptoms total score	Skindex-29, a 29-item dermatology-specific health-related quality of life questionnaire. Linearly transformed to a minimum of 0 and a maximum of 100; higher scores indicate greater impairment.	Every 6 months, from enrollment up to 10 years
Skindex-29 symptoms subscale score	Skindex-29, a 29-item dermatology-specific health-related quality of life questionnaire. Symptoms subscale, linearly transformed to a minimum of 0 and a maximum of 100; higher scores indicate greater impairment.	Every 6 months, from enrollment up to 10 years
Skindex-29 emotions subscale score	Skindex-29, a 29-item dermatology-specific health-related quality of life questionnaire. Emotions subscale, linearly transformed to a minimum of 0 and a maximum of 100; higher scores indicate greater impairment.	Every 6 months, from enrollment up to 10 years
Skindex-29 functioning subscale score	Skindex-29, a 29-item dermatology-specific health-related quality of life questionnaire. Functioning subscale, linearly transformed to a minimum of 0 and a maximum of 100; higher scores indicate greater impairment.	Every 6 months, from enrollment up to 10 years
Patient Activation Measure (PAM-13) activation score	Patient Activation Measure, a 13-item questionnaire on knowledge, skill and confidence in self-management. Raw scores are transformed to an activation score with a minimum of 0 and a maximum of 100; higher scores indicate greater patient activation.	Every 6 months, from enrollment up to 10 years
Client Satisfaction Questionnaire, four-item short form (CSQ-4) total score	Client Satisfaction Questionnaire, four-item short form, measuring satisfaction with the care received. Each item scored 1 to 4; total score minimum 4, maximum 16; higher scores indicate greater satisfaction.	Every 6 months, from enrollment up to 10 years
Number of disease exacerbations	Count of exacerbations per participant, an exacerbation being defined as a step-up in treatment (initiation or escalation of topical, systemic or biologic therapy) or a prescription of rescue medication, identified from routine electronic health record data. Unit: number of exacerbations per participant-year.	Continuously from enrollment, up to 10 years
Number of outpatient dermatology visits	Count of face-to-face outpatient dermatology visits per participant, identified from hospital procedural codes. Unit: number of visits per participant-year.	Continuously from enrollment, up to 10 years
Number of remote consultations	Count of telephone and other remote dermatology consultations per participant, identified from hospital procedural codes. Unit: number of consultations per participant-year.	Continuously from enrollment, up to 10 years
Number of hospital admissions	Count of hospital admissions per participant, identified from hospital procedural codes. Unit: number of admissions per participant-year.	Continuously from enrollment, up to 10 years
Healthcare costs	Costs associated with dermatological care per participant, reported as total costs, hospital-related costs and patient-related costs (including travel costs and absenteeism from work or school), derived from hospital procedural codes and standard Dutch unit costs. Unit: euros per participant-year.	Continuously from enrollment, up to 10 years
Therapy adherence	Adherence to prescribed dermatological therapy, derived from national pharmacy dispensing records (LSP), expressed as medication possession ratio or proportion of days covered. Unit: percentage; minimum 0, maximum 100; higher values indicate better adherence.	Continuously from enrollment, up to 10 years
Inter-rater reliability of photograph-derived PASI (intraclass correlation coefficient)	Agreement between calibrated raters scoring the Psoriasis Area and Severity Index from the same home photograph sets, quantified as an intraclass correlation coefficient (two-way mixed model, absolute agreement, single measures). Minimum 0, maximum 1; higher values indicate better agreement between raters.	Assessed at each two-yearly cohort evaluation, up to 10 years
Inter-rater reliability of photograph-derived EASI (intraclass correlation coefficient)	Agreement between calibrated raters scoring the Eczema Area and Severity Index from the same home photograph sets, quantified as an intraclass correlation coefficient (two-way mixed model, absolute agreement, single measures). Minimum 0, maximum 1; higher values indicate better agreement between raters.	Assessed at each two-yearly cohort evaluation, up to 10 years
Inter-rater reliability of photograph-derived IHS4 (intraclass correlation coefficient)	Agreement between calibrated raters scoring the International Hidradenitis Suppurativa Severity Score System from the same home photograph sets, quantified as an intraclass correlation coefficient (two-way mixed model, absolute agreement, single measures). Minimum 0, maximum 1; higher values indicate better agreement between raters.	Assessed at each two-yearly cohort evaluation, up to 10 years
Inter-rater agreement on photograph-derived refined Hurley stage (weighted kappa)	Agreement between calibrated raters assigning the refined Hurley stage to the same home photograph sets, quantified as a weighted kappa coefficient. Minimum -1, maximum 1; higher values indicate better agreement between raters, and 0 indicates agreement no better than chance.	Assessed at each two-yearly cohort evaluation, up to 10 years
Effect of access to the clinical record on photograph-derived PASI scoring	Mean paired difference in Psoriasis Area and Severity Index score between raters scoring with access to the participant's clinical record and raters scoring from the photographs alone. Unit: points on the Psoriasis Area and Severity Index (range 0 to 72); a positive difference indicates higher scores when the clinical record is available.	Assessed at each two-yearly cohort evaluation, up to 10 years
Effect of access to the clinical record on photograph-derived EASI scoring	Mean paired difference in Eczema Area and Severity Index score between raters scoring with access to the participant's clinical record and raters scoring from the photographs alone. Unit: points on the Eczema Area and Severity Index (range 0 to 72); a positive difference indicates higher scores when the clinical record is available.	Assessed at each two-yearly cohort evaluation, up to 10 years
Effect of access to the clinical record on photograph-derived IHS4 scoring	Mean paired difference in International Hidradenitis Suppurativa Severity Score System score between raters scoring with access to the participant's clinical record and raters scoring from the photographs alone. Unit: points on the International Hidradenitis Suppurativa Severity Score System (minimum 0, no predefined maximum); a positive difference indicates higher scores when the clinical record is available.	Assessed at each two-yearly cohort evaluation, up to 10 years
Proportion of photograph sets meeting the pre-specified discordance threshold	Percentage of scored photograph sets in which the range across the three independent continuous severity scores exceeds 10 points, or in which the assigned refined Hurley stages span more than one stage, and which are therefore referred for adjudication. Unit: percentage of scored photograph sets; minimum 0, maximum 100.	Assessed at each two-yearly cohort evaluation, up to 10 years
Monthly questionnaire completion rate	Percentage of scheduled monthly questionnaire sessions that are completed by participants. Unit: percentage of scheduled sessions; minimum 0, maximum 100; higher values indicate more complete data collection. Reported overall and per disease group.	Assessed at each two-yearly cohort evaluation, up to 10 years
Monthly photograph set submission rate	Percentage of scheduled monthly home photograph sessions for which a photograph set is submitted. Unit: percentage of scheduled sessions; minimum 0, maximum 100; higher values indicate more complete data collection. Reported overall and per disease group, and separately for hidradenitis suppurativa, for which photograph submission is optional.	Assessed at each two-yearly cohort evaluation, up to 10 years
Proportion of submitted photograph sets of sufficient quality for severity scoring	Percentage of submitted photograph sets for which raters are able to assign a severity score, judged retrospectively against six predefined quality categories. Unit: percentage of submitted photograph sets; minimum 0, maximum 100; higher values indicate better usable image quality.	Assessed at each two-yearly cohort evaluation, up to 10 years
Distribution of photograph quality failure reasons	Percentage of non-scoreable photograph sets, broken down by the six predefined rejection categories: blur or motion artefact; insufficient or uneven lighting; incorrect framing or distance; incomplete coverage of the affected body area; identifiable features visible outside the consented scope; and other. Unit: percentage of non-scoreable photograph sets per category; minimum 0, maximum 100.	Assessed at each two-yearly cohort evaluation, up to 10 years
Body region coverage state distribution	Percentage of assessed body regions in each of three predefined coverage states: photographed and scored; reported as affected but not photographed; and reported as clear. Unit: percentage of assessed body regions per state; minimum 0, maximum 100.	Assessed at each two-yearly cohort evaluation, up to 10 years
Scoring turnaround within 90 days	Percentage of photograph sets passing quality review that are scored by all three assigned raters within 90 days of submission. Unit: percentage of quality-passed photograph sets; minimum 0, maximum 100; higher values indicate faster completion of scoring.	Assessed at each two-yearly cohort evaluation, up to 10 years
Annual participant attrition rate	Percentage of participants active at the start of a given year who leave the study during that year, either by formal withdrawal or by meeting the criterion of three consecutive missed assessments. Unit: percentage of active participants per year; minimum 0, maximum 100; higher values indicate poorer retention.	Assessed at each two-yearly cohort evaluation, up to 10 years
Number of actively participating participants per disease group	Count of participants meeting the definition of active participation, reported separately for psoriasis, atopic dermatitis and hidradenitis suppurativa. Unit: number of participants.	Assessed at each two-yearly cohort evaluation, up to 10 years

Collaborators and Investigators

• Sponsor: Medisch Spectrum Twente
• Collaborators: Ziekenhuisgroep Twente

Publications and helpful links

Helpful Links

• Dutch site of registration

Study record dates

Study Major Dates

• Study Start (Estimated): October 1, 2026
• Primary Completion (Estimated): September 1, 2036
• Study Completion (Estimated): September 1, 2036

Study Registration Dates

• First Submitted: August 26, 2026
• First Submitted That Met QC Criteria: August 31, 2026
• First Posted (Actual): September 4, 2026

Study Record Updates

• Last Update Posted (Actual): September 4, 2026
• Last Update Submitted That Met QC Criteria: August 31, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: atopic dermatitis; patient reported outcome measures; psoriasis; teledermatology; hidradenitis suppurativa; patient-acquired photography
• Additional Relevant MeSH Terms: Genetic Diseases, Inborn; Immune System Diseases; Infections; Hypersensitivity, Immediate; Hypersensitivity; Skin Diseases, Papulosquamous; Skin Diseases; Bacterial Infections; Bacterial Infections and Mycoses; Sweat Gland Diseases; Skin Diseases, Bacterial; Skin Diseases, Infectious; Suppuration; Skin Diseases, Genetic; Skin Diseases, Eczematous; Dermatitis; Hidradenitis; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Skin and Connective Tissue Diseases; Hidradenitis Suppurativa; Psoriasis; Dermatitis, Atopic; Eczema
• Other Study ID Numbers: NL-011912

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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