Solar urticaria (SU) is a rare, poorly understood photodermatosis characterized by inappropriate mast cell degranulation following cutaneous exposure to sunlight. Based on a lack of Mendelian inheritance in families and its onset in adulthood with limited impact on reproductive fitness, SU is likely a complex trait whose development is determined by genetic and environmental factors. Its rarity and unusual phenotype, which constitutes an extreme aberration of physiological responses to sunlight, imply that its genetic architecture may be underpinned by rare, highly penetrant and deleterious variants. To investigate this, we performed a case–control whole-exome sequencing gene association study in SU. Forty-six patients of European ancestry with phototest-confirmed SU underwent whole-exome sequencing. Healthy control whole exomes (n = 971) were derived from the 1958 British Birth Cohort. Following quality control, joint variant calling and variant filtering to retain rare, high-impact variants, burden testing was performed. Sanger sequencing and bioinformatic resources were used to validate and explore identified genes/variants. Burden testing revealed exome-wide significant enrichment of rare, high-impact variants in ACACA among SU cases (P = 4.7 × 10−7). This gene encodes acetyl-coenzyme A carboxylase alpha, an enzyme that catalyses the rate-limiting step in de novo lipogenesis. Six of 46 SU cases carried rare, heterozygous missense variants in ACACA compared with 3 of 971 controls. Sanger sequencing validated the presence of these variants in ACACA. Structural analyses demonstrated that ACACA variants were predicted to decrease protein stability. Reanalysis of single-cell RNA sequencing data from skin confirmed ACACA expression in all cell types, including mast cells. Enrichment of rare, deleterious ACACA variants among patients with SU suggests a role for altered lipid metabolism, potentially affecting mast cell function, in SU pathogenesis. Characterization of lipid-mediated disease mechanisms in SU should form the basis of future investigations.

Abstract Narrowband ultraviolet B (NB-UVB) light sources have an established role in phototherapy. They are widely available in general dermatology but can also be utilized for phototesting. Aiming to improve phototesting accessibility, we investigated the accuracy and reliability of NB-UVB minimal erythema dose (MED) compared with the 305 ± 5-nm monochromator MED as determined in the tertiary photobiology service. Ethics approval was obtained (CALDICOTT-2025-256) and patients’ data were collected from an in-house database and analysed by two members of the research team using Microsoft Excel. Duplicates and return visits were removed, so data from 513 individual patients were included. Abnormal NB-UVB photosensitivity was defined as MED < 82 mJ cm−2. Abnormal 305 ± 5-nm photosensitivity was defined as MED < 33 mJ cm−2. NB-UVB MED testing had a specificity of 96% and sensitivity of 64%. The kappa (κ) score between NB-UVB and 305 ± 5 nm was 0.65, indicating substantial agreement, but the false negative rate of 36% makes it unsuitable in undifferentiated patients. Subgroup analysis investigated the sensitivity of NB-UVB MED in different conditions. The NB-UVB MED was shown to be useful in diagnosing chronic actinic dermatitis (CAD) (n = 99): specificity 79%, sensitivity 84%, κ = 0.47. It was not useful in poly­morphic light eruption (n = 147): specificity 96%, sensitivity 8%, κ = 0.05. The NB-UVB MED was not helpful in diagnosing solar urticaria according to our small patient cohort (n = 34), with only 38% sensitivity despite 100% specificity. Overall, the findings of this study demonstrate that NB-UVB MED testing has an effective role in phototesting, especially the unique suitability of the NB-UVB lamp in diagnosing patients with CAD. It is important to be able to identify CAD using NB-UVB MED testing, as the condition can be clinically indistinguishable from photoaggravated atopic dermatitis. NB-UVB phototherapy is available in most secondary dermatology centres. We therefore recommend that NB-UVB MED testing is an accessible safety measure to detect abnormal CAD photosensitivity.

Abstract We aimed to characterize the clinical features, phototesting findings and implicated drugs among patients with suspected drug photosensitivity. Patients were recruited at a referral or initial specialist assessment at a tertiary photodiagnostic service between 2014 and 2024. A retrospective review of an in-house photodiagnostic database and clinical records was undertaken, with Caldicott Guardian approval (IGTCAL-2024-409). Demo­graphic and clinical data, suspected culprit drugs and photodiagnostic findings were analysed, with diagnosis based on clinical assessment, drug history, response to withdrawal and phototesting. During the study period, 2535 patients attended, 54 (2%) with suspected drug photosensitivity. Following assessment, drug-induced photosensitivity was the primary diagnosis in 34 (63%), contributory in 15 and excluded in 5. Among primary or contributory cases (n = 49), 57% of patients (n = 28) were female, median age 58 years (range 25–85). Where recorded, 76% had phototypes I–II. Monochromator phototesting showed reduced erythemal thresholds in 33 patients (67%): 45% ultraviolet (UV)A alone, 27% UVA and visible, 18% UVA and UVB, and 9.1% visible alone. Where phototesting was normal or not performed, this reflected drug discontinuation before phototesting, lack of photo­testing or strong clinical suspicion despite normal phototesting. Among primary cases (n = 34), phototoxic reactions predominated (82%), with pseudoporphyria (9%), drug-induced lupus (6%) and solar urticaria (3%). Implicated drugs included diuretics (14%, mainly thiazides), statins (12%), immunomodulatory agents (12%), nonsteroidal anti-inflammatory drugs (12%), quinine (8%), oncological therapies (8%), antihypertensives (8%), antimicrobials (6%), proton-pump inhibitors (6%), anti­fibrotics (4%), antiepileptics (4%) and other agents (4%). The median latency from drug commencement to symptom onset was 24 months (range ∼1 day to 30 years; n = 39). Drug-induced photosensitivity accounted for a small but significant proportion of referrals. Emerging drugs were implicated, including oncological and antifibrotic therapies. Although phototesting showed UVA-predominant sensitivity, normal testing did not exclude drug causality, emphasizing clinical correlation. Clinicians should not be falsely reassured by prolonged drug exposure prior to symptom onset – clinical assessment and, where feasible, phototesting are essential.

Monochromator phototesting is a specialist investigation to assess abnormal skin response to defined ultraviolet and visible wavebands in patients with suspected photodermatoses. Monochromator phototesting spans ultraviolet B (UVB), ultraviolet A (UVA) and visible light (VL) and is used in specialist UK photodiagnostic centres. Abnormal-response yield varies between individuals and diagnostic groups. However, the procedure is time- and resource-intensive and limited to specialist centres. To identify the wavebands and waveband combinations that captured the greatest proportion of abnormal monochromator responses, and to explore whether these findings could inform future evaluation of limited-waveband approaches within specialist phototesting pathways. This retrospective single-centre analysis included 668 phototesting results from 552 individuals collected between 2020 and 2025 at the Scottish Photobiology Service, NHS Tayside, Dundee, UK. Records prior to 2020 were reviewed in some selected patients to distinguish persistently negative monochromator tests from previously documented abnormal responses that had resolved before the study period. Assessed wavebands were 305 ± 5 nm (UVB), 335 ± 27 nm (UVB + UVA), 365 ± 27 nm (UVA), 400 ± 27 nm (UVA + VL) and 430 ± 27 nm (VL). Of 552 individuals, 353 received a final clinical diagnosis of photodermatosis and 199 did not. Across individuals with photodermatoses, 335 nm showed the highest single-wavelength abnormal-response yield (203/353, 57.5

Abstract Photodermatoses such as solar urticaria and chronic actinic dermatitis cause heightened sensitivity to outdoor and, in some cases, indoor light, leading to pain, pruritus and prolonged erythema. These conditions substantially affect quality of life, with rates of psychological comorbidity higher than in the overall population. Management relies on rigorous photoprotection and limiting exposure to ultraviolet and visible light, yet many patients struggle to judge real-time light conditions and remain uncertain when cumulative exposure may reach their individual symptom threshold. Few tools provide personalized, objective feedback to help guide everyday decisions about light avoidance. Following discussions with patients, we explored the potential of repurposing ExpoDose®, a research-grade solar monitoring platform, as a support tool for managing photosensitivity. ExpoDose® integrates GPS-derived location and satellite irradiance data to estimate ambient solar exposure through a smartphone app. The APPETISER study (Assisting Photosensitive Patients Excel Through Information on Sun Exposure: a Realism Study) was developed as a clinical service initiative to evaluate technical feasibility, usability and perceived value for individuals living with photosensitivity. Engagement was high, with 89% of participants using the app daily and reporting it to be easy to use. Overall, 78% expressed at least some level of satisfaction, and 67% felt their ability to manage photosensitivity improved during the evaluation. When asked to rate the app’s contribution to this improvement on a 0–10 scale, the mean score was 7. Although 89% wished to continue using the app, only 11% were willing to pay for it in its current form. A 35% dropout rate, largely due to technical issues, influenced overall outcomes. Nonetheless, patient responses demonstrated strong interest in tools that help contextualize daily solar exposure and support self-management. Although the app will not enter routine practice, future work will explore what motivates behaviour change among people living with photodermatoses.

Abstract Photopatch testing and photodiagnostic investigations are important in the assessment of suspected photosensitivity conditions and are typically delivered through tertiary photodiagnostic services. We reviewed patients who had been photopatch tested through such a service from 2020 to 2025, documenting clinical features and photodiagnostic findings, to assess current practices. This retrospective study was conducted with Caldicott Guardian approval (IGTCAL-2025-296). Study data were obtained through review of clinical photodermatology records and an in-house photodiagnostic database. The median age of the 157 patients studied was 46 years (range 3–83), with 121 (77%) female. Most had skin phototype I–III (115 of 126 with data, 91%) and 88 of 157 (56%) were atopic. The majority used sunscreens (95 of 115, 83%). Most (115 of 157, 73%) presented with facial dermatitis and/or swelling, and of those, 68 of 115 (59%) used sunscreen. Photopatch testing identified photocontact allergy in 20 of 157 (13%) and contact allergy in 41 of 157 (26%). Of those with positive photocontact and/or contact allergy (n = 57), 79% were female, and 72% presented with facial dermatitis and/or swelling. Of those who also had standard patch testing, 77 of 98 (79%) had positive results. The most frequent photopatch test photoallergens or allergens were Uvistat® SPF50 (n = 23), Sunsense Sunsensitive® SPF 50+ (n = 21), octocrylene (n = 8), lauryl polyglucose (n = 7) and oxybenzone (n = 3). Abnormal monochromator phototesting occurred in 68 of 151 (45%), with 7 of 133 (5%) patients tested having an abnormal narrowband ultraviolet B minimal erythema dose. Vitamin D insufficiency (< 50 nmol L−1) occurred in 55 of 120 (46%) and elevated IgE (> 100 kU L−1) in 44 of 99 (44%). The median Dermatology Life Quality Index was 12 (range 1–30) (n = 137). While the most prevalent diagnosis was polymorphic light eruption (58 of 157; 37%), a range of diagnoses were reported, including photocontact allergy and other photodermatoses. We wish to highlight the importance of photopatch testing, particularly in female patients with facial dermatitis and/or swelling. The diverse range of diagnoses identified highlights the need for comprehensive assessment through specialized photo­diagnostic services.

Chronic actinic dermatitis (CAD) is a chronic photosensitivity disorder typically characterized by an eczematous eruption on photoexposed sites. Diagnosis relies on specialist phototesting, but there is no consensus on formal diagnostic criteria. As part of the efforts by the British Photodermatology Group to develop a set of diagnostic criteria for CAD, this study was undertaken to gain a deeper understanding of the clinical and photobiological disease characteristics of CAD in the UK. A retrospective review of medical records and in-house databases was undertaken for 5–25 patients diagnosed with CAD at each of six photobiology units in the UK. Data collected included patient demographics, disease characteristics and investigation findings. Data were available for 93 patients with CAD; 51% were male. The median age at diagnosis was 44 years (range 8–85), and the median age of photosensitivity onset was 33 years (range 4–80). Skin phototypes (SPTs) were I–IV in 62%, V–VI in 33%, and unrecorded in 4% of patients. Patients with SPT I–IV were predominantly male (59%), while those with SPT V–VI were mainly female (61%). The duration of sunlight exposure required to provoke symptoms was < 1 h in 59% of cases, and perennial symptoms were noted in 52%. Concurrent atopic diseases were common, with 46% having atopic dermatitis, 40% asthma, 46% hay fever and 53% elevated IgE levels. Only 32 (34%) patients were vitamin D sufficient, including 12 taking oral supplements. Monochromator phototesting revealed reduced minimal erythema doses (MEDs) in ultraviolet (UV)B wavebands (300–305 nm) in 83–84% of cases, mid-UVA (350–365 nm) in 70–74%, and longer UVA (380–400 nm) in 11–19%. Notably, the greatest reductions in MED occurred at 300 nm (28% of the lowest normal range). Broadband provocation testing was conducted in 77% of cases, with 81% showing abnormal reactions to broadband UVA and 94% to solar simulated radiation. Most patients who were patch or photopatch tested had positive reactions, with only 29% testing negative. In this national dataset, CAD was found to affect people with a wide range of ages and skin phototypes, and atopic disease and vitamin D deficiency were common. Patients with CAD exhibit significant photosensitivity, with flare-ups triggered by brief UV exposure. Phototesting plays a crucial role in identifying the disease’s action spectrum, revealing typically broad-spectrum UV waveband involvement, with marked UVB sensitivity and often also UVA involvement. These data help to further characterize this challenging condition and provide important insights, which will facilitate consensus practices in photodiagnosis.

Actinic prurigo (AP) is a rare chronic photosensitivity condition that typically presents in childhood and may resolve in adolescence. Although less frequent in adulthood, AP can present at this age and may be persistent. The aim of this study was to characterize the clinical presentation, investigation findings, disease course and prognosis of AP in Scotland. This was a retrospective review of patients with AP seen between March 2015 and December 2024 through the Scottish Photobiology Service (SPS). Data on disease characteristics, investigation findings and management were collected from the SPS database and patient records. In total 16 patients with AP were identified. Fifteen were female and one was male, and 11 were newly diagnosed. Ten (63%) had disease onset before age 16 years, with a median age of 10.5 years (range 1–50). Eight (50%) first presented in adulthood (> 16 years old). The most common acute eruption morphology was pruritic erythematous papules (70%). Among adult-onset cases, papulovesicular eruptions were most prevalent (67%). Half of the patients reported scarring. All patients had facial involvement, especially on the cheeks, nose and ears (44% each). Conjunctival involvement occurred in five (31%), and only three (19%) reported cheilitis. Nine (56%) were initially considered to have polymorphic light eruption (n = 5), hydroa vacciniforme (n = 2) or chronic actinic dermatitis (n = 2). Monochromator phototesting at presentation revealed normal action spectra in six (38%), with two developing monochromator ultraviolet (UV)A sensitivity over time. Four (25%) had UVA sensitivity only, four (25%) had UVB and UVA sensitivity and two (13%) had UVB, UVA and visible light sensitivity. Iterative UVA provocation testing showed papular reaction in six (38%), and abnormal erythema in another three (19%). Human leucocyte antigen (HLA) typing was available for 13 patients. Twelve (92%) were positive for HLA-DR4, with nine (75% with HLA-DR4) having the HLA-DRB1*0407 subtype. Twelve patients had follow-up visits, with a median follow-up of 10.8 years (range 1–28.4). Among seven young-onset cases, six (86%) showed marked improvement in clinical symptoms, with five (71%) having normalization of monochromator testing. In contrast, four of five patients (80%) with adult-onset AP remained symptomatic, with persistent abnormal phototesting. AP is a rare immunological photosensitivity disorder that is challenging to diagnose and must be kept in mind. The study found a higher than expected number of adult-onset cases, which tend to follow a more persistent course and are less likely to resolve spontaneously. HLA testing is a useful diagnostic marker, with particular utility in the more atypical adult-onset presentations of AP.

Far-ultraviolet-C (far-UVC) radiation, with its germicidal properties, shows promise in reducing the spread of infectious diseases in public and healthcare settings. Emerging evidence suggests minimal risk to human skin and eyes, but its safety for patients with photosensitivity disorders remains uncertain. This study aims to fill this gap by assessing the safety of far-UVC exposure for individuals with these conditions.

Managing photosensitivity conditions, including polymorphic light eruption (PLE), chronic actinic dermatitis (CAD), solar urticaria (SU) and cutaneous porphyria, necessitates comprehensive photoprotection strategies. Sunscreens, a cornerstone of these strategies, can pose unique challenges for photosensitive individuals, who may not have an ultraviolet or visible light sensitivity that corresponds to the standard erythema curve. This can mean sunscreen effectiveness for these individuals is not adequately addressed by the product’s sun protection factor (SPF). However, if an individual has heightened visible light sensitivity, as typically seen in SU or porphyria, this does not necessarily mean a visible light-protecting sunscreen is the best choice. This was previously shown for a patient with visible light-sensitive SU who had greater effectiveness with an SPF 50+ formulation without visible light filters compared with one that did. It is thus challenging for people with photosensitivity to know how to select an appropriate sunscreen or for clinicians to advise on optimal choices. This study aimed to evaluate real-world sunscreen usage among photosensitive individuals, exploring factors involved in sunscreen choices, including the role and importance of UV and visible light protection. A structured questionnaire was developed and distributed through the Scottish Photobiology Service and the British Porphyria Association to individuals with a range of photosensitivity conditions, collecting data on sunscreen preferences, usage challenges and visible light protection awareness. There were 82 responses. Difficulties with sunscreen use were reported by 44%, with approximately half expressing dissatisfaction with certain products. Variations in adoption of visible light-protecting sunscreens were observed across conditions. For individuals with CAD, 17% used visible-protecting sunscreen and 50% did not; 33% were not ascertained (NA). For individuals with SU, only 8% used visible-protecting sunscreens and 58% did not (33% NA). With PLE, 43% used visible-protecting sunscreens and 43% did not (14% NA). For photosensitive porphyria, 56% confirmed visible-protecting sunscreen usage, while 32% did not (12% NA). Those without a clear photosensitivity diagnosis showed the lowest uptake of visible-protecting sunscreens (0%), with 65% not using them (35.3% NA). These findings highlight the complexity of sunscreen choices and usage for photosensitive individuals. Given that almost half of responders with porphyria, and > 90% of those with SU, were not using visible-protecting sunscreens, this also highlights the challenges for clinicians in recommending sunscreen choices based on diagnosis, although further detailed evaluation into the reasons behind sunscreen choices is required. Close collaboration with industry is needed to highlight the specific challenges of sunscreen choices for patients with photosensitivity diseases, with emphasis on individualized approaches as the mainstay of photoprotection.

ABSTRACT Background Topical photodynamic therapy (PDT) is widely used in dermatology for treating superficial non‐melanoma skin cancer (NMSC) and dysplasia. This study aims to assess real‐world outcomes of PDT in a Scottish dermatology service. Methods We retrospectively reviewed patients with superficial NMSC and dysplasia who underwent conventional and daylight PDT at the Photobiology Unit, Dundee, Scotland. Results A total of 705 patients with 2108 NMSC and precancerous skin lesions underwent conventional PDT. Clearance at 12 months was achieved in 53.4% of actinic keratoses (AK), 71.3% of Bowenoid AK, 86.4% of Bowen's disease (BD), 89.0% of superficial basal cell carcinoma (BCC), and 89.7% of nodular BCC. On multivariate analysis, small lesion size and thin histological tumour thickness of superficial BCC were features, which were associated with likelihood of achieving clearance after PDT. Female sex, head/neck sites, larger lesion size, strong pre‐treatment fluorescence intensity, fluorescence specificity, prominent treatment‐induced erythema and an urticarial reaction were associated with moderate to severe pain during PDT. Daylight PDT for 77 AK patients (158 treatments) showed excellent or good outcomes in 63.3% of lesions. Higher visible light exposure is correlated with better treatment outcomes. Conclusions In real‐life settings, whilst the PDT response rates of BD and selected BCC are high and consistent with clinical trial outcomes, the efficacy rates for AK appear lower than expected. This emphasizes the need for realistic expectations in chronic disease management. Through review over a prolonged period, factors associated with PDT tolerability and outcomes were identified, allowing predictive utilisation for optimizing patient‐centred PDT regimens.

Far-ultraviolet C (Far-UVC) light, with its germicidal properties, shows promise in reducing the spread of infectious diseases in public and healthcare settings. Emerging evidence suggests minimal risk to human skin and eyes, but its safety for patients with photosensitivity disorders remains uncertain. This study aims to fill this gap by assessing the safety of Far-UVC exposure for individuals with these conditions.

BACKGROUND/OBJECTIVES:Individuals with photosensitivity diseases, including porphyria, face significant challenges in managing their condition due to heightened sensitivity to ultraviolet (UV) and visible light. Comprehensive photoprotection strategies are essential and prioritize environmental modifications, behavioral adjustments, protective clothing, and hats. Sunscreens serve as a supplementary measure, particularly for exposed skin areas not otherwise protected. However, the extensive variety of available sunscreen products and limited guidance on their efficacy complicate the selection process. This study evaluates sunscreen use among photosensitive individuals and gathers feedback to inform future service development and research. METHODS:A questionnaire was completed by 32 individuals with porphyria (mostly with porphyrias causing skin photosensitivity) and 50 individuals with non-porphyric photosensitivity conditions, totaling 82 participants. The survey assessed preferences and experiences with sunscreens, focusing on criteria such as protection efficacy, cost, availability, and ease of use. Responses were analyzed to identify trends and challenges in integrating sunscreens into broader photoprotection strategies. RESULTS:Protection efficacy was the primary factor influencing sunscreen choice among photosensitive patients, highlighting its importance alongside other photoprotection measures. The survey revealed considerable variation in sunscreen use. La Roche-Posay was the most favored brand. While 56% of porphyria patients used sunscreens explicitly labelled for visible light protection, only 11% of non-porphyric patients did so. Overall, 40% of participants reported issues with sunscreens, and approximately half expressed dissatisfaction with certain products, emphasizing the need for more effective and user-friendly options. CONCLUSIONS:Sunscreens are a critical adjunct to broader photoprotection strategies for photosensitive patients but are not a standalone solution. Particularly for those with porphyrias, effectiveness was regarded as especially important. The variability in product preferences and the frequent difficulties reported highlight the need for improved guidance and accessibility of sunscreens tailored to diverse photosensitivity needs. Future research should focus on developing clear recommendations and expanding options to ensure effective and personalized photoprotection.

This study investigates the effectiveness of ultraviolet (UV) protection provided by various types of glasses for patients who have orally ingested psoralen. Psoralen is administered orally by patients, as part of PUVA photochemotherapy, 2 h prior to ultraviolet-A exposure. For 12–24 h post psoralen ingestion, there is a potential risk of ocular damage from solar UV (Lerman et al. in J Investig Dermatol 74(4):197–199, 1980). The patients must, therefore, wear eye protection during this period. The purpose of this study was to evaluate the effectiveness of commonly used eyewear for ocular protection during PUVA therapy. A range of glasses, including commercially available sunglasses, prescription sunglasses, prescription glasses without UV protection, and UV protective eyewear, were evaluated. The UV transmission rates of the lenses were measured using a spectrophotometer, followed by a spectroradiometer experiment with a UVA light source to assess the relative UV exposure of the eyewear. The results indicate that while standard UV-protective glasses effectively block UV transmission through the lens, real-world scenarios reveal that inadequate frame coverage can significantly reduce overall eye protection. This highlights the limitation of relying solely on lens transmission as a measure of protection and underscores the critical role of selecting well-designed frames with proper fit for patients during psoralen photosensitisation.

Narrow-waveband phototesting is considered the gold standard for diagnosing photosensitive disorders. It spans the solar spectrum covering ultraviolet (UV)B, UVA and visible light wavelengths, typically ranging from 300 nm to 600 nm in all UK phototesting centres (Ibbotson SH, Allan D, Dawe RS et al. Photodiagnostic services in the UK and Republic of Ireland: a British Photodermatology Group workshop report. J Eur Acad Dermatol Venereol 2021; 35: 2448–55). Sensitivity to specific wavelengths varies depending on the individual and their condition. However, narrow-waveband phototesting is currently limited to tertiary centres and can be time consuming and resource intensive. This study aimed to identify the most effective phototesting waveband combination that would cover the majority of photosensitive patients and could potentially serve as a screening tool. A retrospective review was conducted of abnormal monochromator phototest results from 2021 to 2024 in a UK national photobiology unit. The study assessed the following phototesting wavebands: 305 ± 5 nm (UVB), 335 ± 27 nm (UVA), 365 ± 27 nm (UVA), 400 ± 27 nm (visible) and 430 ± 27 nm (visible). In total 217 abnormal monochromator phototest results were included in this study. Among these, 35 (16%) were of abnormal immediate sensitivity, while 182 (84%) showed abnormal delayed sensitivity. The Table summarizes the percentage of photosensitive individuals who exhibited heightened sensitivity to various phototesting wavebands and their combinations. In conclusion, combining multiple phototesting wavebands significantly improves detection rates of photosensitive individuals. Almost 90% of photosensitivity would be detected if screening with UVB and UVA wavelengths (305 nm and 365 nm), which could be improved to 96% by combing with 400 nm. Limited-wavelength phototesting has the potential to be a useful screening approach for photosensitivity.TablePositive phototesting in 217 individualsTesting wavebandPositive results, n (%)305 nm (UVB) only138 (64)335 nm (UVA) only160 (74)365 nm (UVA) only154 (71)400 nm (visible) only85 (39)430 nm (visible) only35 (16)305 nm + 335 nm (UVB + UVA)183 (84)305 nm + 365 nm (UVB + UVA)193 (89)335 nm + 365 nm (UVA)189 (87)400 nm + 430 nm (visible)111 (51)305 nm + 335 nm + 400 nm (UVB + UVA + visible)203 (94)305 nm + 365 nm + 400 nm (UVB + UVA + visible)208 (96)305 nm + 335 nm + 430 nm (UVB + UVA + visible)198 (91)305 nm + 365 nm + 430 nm (UVB + UVA + visible)202 (93)305 nm + 335 nm + 365 nm + 400nm (UVB + UVA + visible)212 (98)UV, ultraviolet.

The Scottish Photobiology Service (SPS), hosted in the Photobiology Unit at Ninewells Hospital, Dundee, celebrated its 50th anniversary in 2023. Dedicated to providing diagnostic and therapeutic services for individuals with cutaneous photosensitivity disorders, the SPS has consistently sought to improve patient care. In 2015, the Chief Medical Officer for Scotland, published a national report entitled 'Realistic Medicine', which challenged medical practitioners to improve patient care through the development of personalised approaches, with patients placed at the centre of their care. In 2019, the SPS initiated a patient engagement programme aimed at better understanding the needs of patients with photosensitivity conditions, underpinning the objectives of the Realistic Medicine concept. This article outlines the development, implementation and outcomes of this initiative, which has become a core function of the service. Through ongoing collaboration with patients and staff, the programme has informed service improvements, addressed key issues such as referral delays, peer support and educational resources, and fostered an inclusive approach to care.