Gabrielle Randskov Vinding

Actinic keratosis is a common, chronic, and potentially pre-cancerous skin disease that can negatively impact patients’ health-related quality of life. This systematic review aimed to identify and describe the questionnaires used to assess health-related quality of life in patients with actinic keratosis and summarize reported impacts. Four databases (EMBASE, PsycINFO, PubMed, and Cochrane Library) were searched up to February 2025. Two reviewers independently screened articles, and risk of bias was assessed using tools appropriate to study design. Of 639 records, 37 studies including 9,326 patients met inclusion criteria. Most studies were interventional (59%) and of moderate to high quality (64%). Health-related quality of life was assessed using 3 disease-specific, 3 dermatology-specific, and 2 generic questionnaires. The most frequently used instruments were the Actinic Keratosis Quality of Life (n = 13) and the Dermatology Life Quality Index (n = 16). All questionnaires detected health-related quality of life impairment, especially during treatment. Actinic Keratosis Quality of Life identified patient subgroups with greater health-related quality of life reduction, including females, younger individuals, patients with comorbidities, and those with a history of skin cancer. All health-related quality of life questionnaires captured impairment in patients with actinic keratosis. The Actinic Keratosis Quality of Life and Dermatology Life Quality Index questionnaires were widely used. Actinic Keratosis Quality of Life identified subpopulations with health-related quality of life impairment. Among studies reporting mean health-related quality of life scores, the Dermatology Life Quality Index ranged from 1.55 to 24 and the Actinic Keratosis Quality of Life from 4.22 to 17, reflecting very broad variability and underlying differences in actinic keratosis severity across study populations.

Background: Socioeconomic status (SES) and access to dermatological care are known to influence rates of keratinocyte carcinoma (KC). However, few studies have examined the impact of these factors on the disease burden of specific KC subtypes. Objectives: To determine the impact of SES and distance to a dermatologist on the burden of KC, determined by tumour incidence rate ratios (TIRRs) and tumour size, for nodular basal cell carcinoma (nBCC), superficial BCC (sBCC), squamous cell carcinoma (SCC) and the KC precursor, Bowen disease (BD). Methods: Using data from the nationwide Danish Skin Cancer Registry, our study included 100 705 patients with 190 468 histologically or clinically verified cases of KC/BD registered in state-funded office-based dermatology practices between 2013 and 2022. Negative binomial regression was used to calculate TIRRs; the impact on lateral tumour size was estimated with log-linear quantile regression. Results: High SES was associated with increased tumour incidence and smaller tumours for all KC subtypes. Rates of nBCC and sBCC were 2.7 times and 2.4 times higher, respectively, among the top 25% earners vs. the lowest income category [nBCC 2.74, 95% confidence interval (CI) 2.69–2.79; sBCC 2.38, 95% CI 2.30–2.47], with top earners having BCC tumours that were up to 9.7% smaller (95% CI 8.5–11.0%). The impact of distance to a dermatologist varied by KC subtype. For nBCC, increasing tumour incidence was noted with shorter distances to a dermatologist, while the opposite trend was seen for SCC and BD. Individuals living further away from a dermatologist had larger nBCC and sBCC tumours. No correlation between tumour size and distance to a dermatologist was found for SCC. Conclusions: High SES was associated with increased tumour incidence and smaller tumours for all KC subtypes, reflecting either higher rates of detection or higher rates of disease occurrence. Distance to a dermatologist was an independent predictor of KC burden, with shorter distances leading to increased tumour incidence but smaller nBCC tumours and decreased incidence of SCC.

Background: Rates of keratinocyte carcinoma (KC) across Europe are impacted by population demographics and geography. Regional differences in KC occurrence exist, but few European studies investigate incidences of specific subtypes in the secondary healthcare sector on a national level.Objectives: To determine geographical differences in incidence rate and lifetime risk of KC subtypes across Denmark, including nodular and superficial basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and the KC precursor, Bowen's disease (BD), identified in office‐based dermatological practice.Methods: Based on a nationwide registry (The Danish Skin Cancer Registry), all patients in Denmark's five regions with a histologically‐ or clinically verified KC or BD registered in a state‐funded office‐based dermatology practice between 2013 and 2022 were included. Trends in national‐ and region‐specific age and sex standardised tumour incidence rates (STIR) were calculated. Further, national lifetime risk of each tumour subtype was estimated.Results: Between 2013 and 2022, the combined STIR for KC/BD rose 172% nationally from 180 to 489 per 100,000 person‐years (PY). This increase reflected rising rates of nodular BCC, SCC, and BD, while superficial BCC incidence was relatively stable. Regional differences in STIR for combined KC/BD were observed, with the Capital Region and North Jutland generally demonstrating higher rates than Zealand, Southern‐ and Central Denmark (e.g., North Jutland vs. Southern Denmark: 714 vs. 405/100,000PY). While the estimated lifetime risk of developing at least one KC or BD tumour was 21.8%, risk varied with tumour subtype, resulting in subtype‐specific risks of 16.4%, 5.1%, 1.9% and 1.3% for nodular BCC, superficial BCC, SCC, and BD, respectively.Conclusions: In Denmark's secondary dermatological care sector, incidence of nodular BCC, SCC and BD continues to rise with an overall lifetime risk nearing 22%. While KC incidence is increasing in Denmark, the study detected differences in geographical trends and rate increases of specific tumour subtypes.

Importance: Ectodermal dysplasias constitute a group of rare genetic disorders of the skin and skin appendages with hypodontia, hypotrichosis, and hypohidrosis as cardinal features. There is a lack of population-based research into the epidemiology of ectodermal dysplasias.Objective: To establish a validated population-based cohort of patients with ectodermal dysplasia in Denmark and to assess the disease prevalence and patient characteristics.Design, Setting, and Participants: This nationwide cohort study used individual-level registry data recorded across the Danish universal health care system to identify patients with ectodermal dysplasias from January 1, 1995, to August 25, 2021. A 3-level search of the Danish National Patient Registry and the Danish National Child Odontology Registry was conducted to identify patients with diagnosis codes indicative of ectodermal dysplasias; patients registered in the Danish RAREDIS Database, the Danish Database of Genodermatoses, and local databases were also added. The search results underwent diagnosis validation and review of clinical data using medical records. Of 844 patient records suggestive of ectodermal dysplasias, 791 patients (93.7%) had medical records available for review. Positive predictive values of the diagnosis coding were computed, birth prevalence was estimated, and patient characteristics were identified. Data analysis was performed from May 4 to December 22, 2023.Results: The identified and validated study cohort included 396 patients (median [IQR] age at diagnosis, 13 [4-30] years, 246 females [62.1%]), of whom 319 had confirmed ectodermal dysplasias and 77 were likely cases. The combined positive predictive value (PPV) for ectodermal dysplasia−specific diagnosis codes was 67.0% (95% CI, 62.7%-71.0%). From 1995 to 2011, the estimated minimum birth prevalence per 100 000 live births was 14.5 (95% CI, 12.2-16.7) for all ectodermal dysplasias and 2.8 (95% CI, 1.8-3.8) for X-linked hypohidrotic ectodermal dysplasias. A molecular genetic diagnosis was available for 241 patients (61%), including EDA (n = 100), IKBKG (n = 55), WNT10A (n = 21), TRPS1 (n = 18), EDAR (n = 10), P63 (n = 9), GJB6 (n = 9), PORCN (n = 7), and other rare genetic variants.Conclusions and Relevance: The findings of this nationwide cohort study indicate that the prevalence of ectodermal dysplasias was lower than previously reported. Furthermore, PPVs of the search algorithms emphasized the importance of diagnosis validation. The establishment of a large nationwide cohort of patients with ectodermal dysplasias, including detailed clinical and molecular data, is a unique resource for future research in ectodermal dysplasias.

Disease-specific quality of life (QoL) questionnaires are increasingly used to provide patient-reported out-come measures in both malignant and non-malignant disease. To create, validate and test the psychometrics of the Skin Cancer Quality of Life (SCQoL), which was designed to measure health-related QoL in patients with non-melanoma skin cancer affecting any area and undergoing any therapy. The SCQoL was developed in a stepwise approach. Three pilot studies (testing content and face validity) and psychometric testing (scale structure, reliability, domains and known-groups validity, concurrent and convergent validity) were conducted. Rasch analyses were performed on the final questionnaire. The initial 10-item questionnaire was reduced to 9 items following interviews and inter-item correlations. The nine item scale was confirmed by Item Response Theory (IRT) and internal consistency. Differential Item Functioning (DIF) was found for a single item, but the effect was small. The final 9-item SCQoL is unidimensional and consists of 3 domains covering function, emotions and control. Furthermore there is one single global item. The total score range from 0 to 27. Higher score denote a greater impairment of the QoL.