Urinary thymidine dimer excretion reflects personal ultraviolet radiation exposure levels.

Exposure to ultraviolet radiation (UVR) leads to skin DNA damage, specifically in the form of cyclobutane pyrimidine dimers, with thymidine dimers being the most common. Quantifying these dimers can indicate the extent of DNA damage resulting from UVR exposure. Here, a new liquid chromatography-mass spectrometry (LC-MS) method was used to quantify thymidine dimers in the urine after a temporary increase in real-life UVR exposure. Healthy Danish volunteers (n = 27) experienced increased UVR exposure during a winter vacation. Individual exposure, assessed via personally worn electronic UVR dosimeters, revealed a mean exposure level of 32.9 standard erythema doses (SEDs) during the last week of vacation. Morning urine thymidine dimer concentrations were markedly elevated both 1 and 2 days post-vacation, and individual thymidine dimer levels correlated with UVR exposure during the last week of the vacation. The strongest correlation with erythema-weighted personal UVR exposure (Power model, r2 = 0.64, p < 0.001) was observed when both morning urine samples were combined to measure 48-h thymidine dimer excretion, whereas 24-h excretion based on a single sample provided a weaker correlation (Power model, r2 = 0.55, p < 0.001). Sex, age, and skin phototype had no significant effect on these correlations. For the first time, urinary thymidine dimer excretion was quantified by LC-MS to evaluate the effect of a temporary increase in personal UVR exposure in a real-life setting. The high sensitivity to elevated UVR exposure and correlation between urinary excretion and measured SED suggest that this approach may be used to quantify DNA damage and repair and to evaluate photoprevention strategies.

Equipment developed for simplifying routine phototesting in dermatology.

Some people react abnormally when exposed to sunlight by getting easily burned or develop a rash. When testing a patient's level of photosensitivity in the clinic, the UVR dose to provoke erythema is determined by the minimal erythema dose (MED) test. Subsequently, a photoprovocation test is performed to detect abnormal skin reactions by daily exposing the skin to UVR for several consecutive days. Associated problems in MED testing include choice of an even skin area for testing, patients keeping still during the test, testing with different UVR doses simultaneously, and securing clear borders of erythema. To address these issues, a MED Test Patch was developed which adheres closely to the skin to ensure sharp erythema borders and provides six irradiation fields with decremental doses of 20%. For MED testing, we constructed a solar simulator and LED lamps with peak emissions at 309 and 370 nm, small enough to be mounted directly on to the MED Test Patch and accommodate patient movements. These lamps and a 415 nm LED can also be used for provocation testing which is best performed on the back where the skin is assumed to have identical UVR sensitivity, and the area is large enough for adjacent MED and provocation test fields. Reading of erythema is still performed by visual and tactile evaluation. The UVA and UVB MED test can be performed in 1 h. The advantage of these developments is an easy-to-use, standardized test method with improved accuracy of the results.

RNA analysis of tape strips to rule out melanoma in lesions clinically assessed as cutaneous malignant melanoma: A diagnostic study.

BACKGROUND: Distinguishing cutaneous malignant melanoma (CMM) from nevi can be clinically challenging. Suspicious lesions are therefore excised, resulting in many benign lesions being removed surgically to find 1 CMM. It has been proposed to use tape strip derived ribonucleic acid (RNA) to distinguish CMM from nevi. OBJECTIVE: To develop this technique further and validate if RNA profiles can rule out CMM in clinically suspicious lesions with 100% sensitivity. METHODS: Before surgical excision, 200 lesions clinically assessed as CMM were tape stripped. Expression levels of 11 genes on the tapes were investigated by RNA measurement and used in a rule-out test. RESULTS: Histopathology showed that 73 CMMs and 127 non-CMMs were included. Our test correctly identified all CMMs (100% sensitivity) based on the expression levels of 2 oncogenes, PRAME and KIT, relative to a housekeeping gene. Patient age and sample storage time were also significant. Simultaneously, our test correctly excluded CMM in 32% of non-CMM lesions (32% specificity). LIMITATIONS: Our sample contained a very high proportion of CMMs, perhaps due to inclusion during COVID-19 shutdown. Validation in a separate trial must be performed. CONCLUSION: Our results demonstrate that the technique can reduce removal of benign lesions by one-third without overlooking any CMMs.

Phototesting in erythropoietic protoporphyria trials: A systematic review.

Severe skin pain when exposed to long wave ultraviolet radiation or visible light is the main symptom of erythropoietic protoporphyria (EPP). Treatment options for EPP are inadequate and new treatments are needed but hampered by the lack of valid efficacy outcomes. Phototesting with well-defined illumination of the skin can be performed reliably. We aimed to provide an overview of phototest procedures used to evaluate EPP treatments. Systematic searches of Embase, MEDLINE and the Cochrane Library were performed. Searches identified 11 studies using photosensitivity as efficacy outcome. The studies used eight different phototest protocols. Illuminations were performed with a filtered high-pressure mercury arc, or a xenon arc lamp equipped with monochromator or filters. Some used broadband, others narrowband illumination. In all protocols phototests were performed on the hands or the back. Endpoints were minimal dose required to induce either first symptom of discomfort, erythema, urticaria or intolerable pain. Other endpoints were change in erythema intensity or diameter of any type of flare after exposure compared to before. In conclusion, protocols displayed extensive variability in illumination set-up and evaluation of phototest reactions. Implementation of a standardized phototest method will allow more consistent and reliable outcome evaluation in future therapeutic research of protoporphyric photosensitivity.

Protection against visible light by dihydroxyacetone in erythropoietic protoporphyria.

BACKGROUND: Patients with erythropoietic protoporphyria (EPP) are hypersensitive to long wave ultraviolet (UVA) radiation and visible light and they experience severe skin pain by light exposure. The patients have very limited treatment options. Sunless skin tanning with dihydroxyacetone (DHA) is now being investigated as a possible treatment modality of skin photosensitivity in EPP. METHODS: We simulated the theoretical light protection factor provided by DHA application. In addition, we present 19 cases with EPP who were treated at our department with DHA weekly during spring and summer from 2018 to 2021 inclusive. RESULTS: The protection factor against UVA and visible light was estimated to approximately two. Out of the 19 patients with EPP who were treated with DHA in 2018, 11 patients experienced a sustained good effect and continued to use the treatment on a weekly basis in the spring and summer of 2019, 2020, and 2021. CONCLUSION AND PERSPECTIVES: Both the theoretical estimates and the uncontrolled study suggest that sunless tanning with DHA reduces photosensitivity in patients with EPP. Our hypothesis is that skin treated with DHA can tolerate twice the daylight dose compared to untreated skin before onset of skin symptoms. To validate this conclusion, we plan a randomized clinical trial to determine the effect of DHA application to reduce photosensitivity in patients with EPP under controlled clinical conditions. The study protocol for this trial is presented in the paper.

Experimental and approved treatments for skin photosensitivity in individuals with erythropoietic protoporphyria or X-linked protoporphyria: A systematic review.

Erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP) are characterized by skin photosensitivity caused by accumulation of protoporphyrin IX. We aimed to review the clinical evidence of efficacy and safety of skin photosensitivity treatments in individuals with EPP or XLP. We systematically searched MEDLINE, Embase, the Cochrane Library, and ClinicalTrials.gov. A total of 40 studies with data on 18 treatment modalities were included. Comprehensive treatment safety data were obtained from the European Medicines Agency and the United States Food and Drug Administration. The studies used different outcome measures to evaluate the sensitivity without a generally accepted method to assess treatment effect on skin photosensitivity. Of the included studies, 13 were controlled trials. Gathered, the trials showed moderate positive effect of inorganic sunscreen application and subcutaneous implant of afamelanotide and no effect of organic sunscreen application, or oral treatment with beta-carotene, cysteine, N-acetylcysteine, vitamin C, or warfarin. Studies without control groups suggested treatment effect of foundation cream, dihydroxyacetone/lawsone cream, narrow-band ultraviolet B phototherapy, erythrocyte transfusion, extracorporeal erythrocyte photodynamic therapy, or oral treatment with zinc sulphate, terfenadine, cimetidine, or canthaxanthin, but the real effect is uncertain. Assessment of treatment effect on photosensitivity in patients with EPP or XLP carries a high risk of bias since experienced photosensitivity varies with both weather conditions, exposure pattern, and pigmentation. Controlled trials of promising treatment options are important although challenging in this small patient population.

Does systemic hydrochlorothiazide increase the risk of developing ultraviolet radiation-induced skin tumours in hairless mice?

Hydrochlorothiazide (HCTZ) is a frequently prescribed diuretic that exhibits photosensitizing properties. It is used to treat hypertension and edema. Dermato-epidemiological studies in various populations have linked HCTZ treatment with increased risk of particular types of skin cancer, including malignant melanoma (lentigo subtype), and both basal cell carcinoma and squamous cell carcinoma (SCC). This study investigated whether either of two different doses of HCTZ increased the risk of SCC development in mice exposed to ultraviolet radiation (UVR). A total of three groups of hairless mice were used in this study (total, N = 71). One group received a low dose (0.26 mg/mouse/day) and another group received a high dose (0.52 mg/mouse/day) of HCTZ in their drinking water; a third UVR control group received only tap water. All three groups were irradiated with UVR until the mice developed three tumours that were 4 mm in size. The times to SCC tumour development were recorded. In the low-dose group, the median time to develop an SCC tumour was 170 days; in both the high-dose group and the control group, the median time to develop anexd SCC tumour was 163 days (p ≥ 0.331). In our hairless mouse model, we found that mice treated with UVR plus HCTZ did not develop SCCs more rapidly than mice treated with UVR but not HCTZ.

Comparison of global DNA methylation analysis by whole genome bisulfite sequencing and the Infinium Mouse Methylation BeadChip using fresh and fresh-frozen mouse epidermis.

Until recently, studying the murine methylome was restricted to sequencing-based methods. In this study we compared the global DNA methylation levels of hairless mouse epidermis using the recently released Infinium Mouse Methylation BeadChip from Illumina and whole genome bisulphite sequencing (WGBS). We also studied the effect of sample storage conditions by using fresh and fresh-frozen epidermis. The DNA methylation levels of 123,851 CpG sites covered by both the BeadChip and WGBS were compared. DNA methylation levels obtained with WGBS and the BeadChip were strongly correlated (Pearson correlation r = 0.984). We applied a threshold of 15 reads for the WGBS methylation analysis. Even at a threshold of 10 reads, we observed no substantial difference in DNA methylation levels compared with that obtained with the BeadChip. The DNA methylation levels from the fresh and the fresh-frozen samples were strongly correlated when analysed with both the BeadChip (r = 0.999) and WGBS (r = 0.994). We conclude that the two methods of analysis generally work equally well for studies of DNA methylation of mouse epidermis and find that fresh and fresh-frozen epidermis can generally be used equally well. The choice of method will depend on the specific study's aims and the available resources in the laboratory.

Quantification of Urinary Thymidine Dimers in Volunteers After Ultraviolet Radiation Using a New UPLC-MS/MS-based Method.

BACKGROUND/AIM: Solar ultraviolet radiation (UVR) is a carcinogen and irradiation of the skin results in DNA damage. Cyclobutane pyrimidine dimers (CPDs), including thymidine dimers, are among the most frequent forms of DNA damage. When CPDs are formed, the nucleotide excision repair system is activated and CPDs are excreted in the urine. Here, we developed a mass spectrometry-based method to quantify thymidine dimers in the urine and tested the method on a small group of volunteers after whole-body UVR exposure. PATIENTS AND METHODS: Years of research resulted in a method based on the "dilute-and-shoot" principle and ultra-performance liquid chromatography (UPLC) coupled to mass spectrometry. The whole body of each of eight healthy volunteers was exposed to 1.5-2.0 standard erythema doses (SEDs) of UVR for 3 consecutive days. Morning urine was collected on Day 1 (before irradiation) and on the following 7-9 days. Prior to analysis, sample preparation consisted of a simple dilution. A tandem quadrupole mass spectrometer coupled to UPLC was used for quantitative analysis in the multiple reaction monitoring mode. RESULTS: After 3 consecutive days of 1.5-2 SEDs, the highest level of thymidine dimer excretion occurred on Day 6 (0.7 ng/ml urine). Compared with baseline, significantly more thymidine dimers were excreted every day until Day 8 (p<0.016). Our method quantifies thymidine dimers that are excreted as dimers (i.e., not degraded further) after nucleotide excision repair. CONCLUSION: This is the first published mass spectrometry-based method for quantifying thymidine dimers in the urine after whole-body UVR exposure.

Counteracting Side-effects of Photodynamic Therapy for Actinic Keratoses.

BACKGROUND/AIM: Actinic keratoses (AKs) are precursors of squamous cell carcinomas and early intervention is important. Photodynamic therapy (PDT) is often first-choice treatment for widespread AKs. Classic PDT consists of: Superficial curettage, application of 5-aminolevulinic acid or methyl aminolevulinate, incubation and protoporphyrin IX (PpIX) accumulation under occlusion for 3 hours, followed by illumination with red light-emitting diode light (37 J/cm2). Classic PDT is effective in treating AKs, but side-effects include unpleasant pretreatment, severe pain during illumination, inflammation after treatment, and long waiting time in the clinic. MATERIALS AND METHODS: This targeted mini review describes efforts to counteract side-effects and simplify the procedure considering the clinic capacity. Changes are only acceptable if treatment effect is maintained. RESULTS: We introduce the following procedure changes: (i) reducing pre-treatment pain, bleeding, and oozing by omitting curettage; (ii) long-term illumination for 2 hours during PpIX formation (already in use as daylight PDT) and shortening of incubation time from 3 hours to 30 minutes to minimize pain and inflammation risk. In addition, options of timing, incubation, and illumination indoors and outdoors are discussed, focusing on advantages and disadvantages for patients and clinics. CONCLUSION: We report several options to counteract side-effects of classic PDT.

High Oral Vitamin D3 Intake Does Not Protect Against UVR-induced Squamous Cell Carcinoma in Mice.

BACKGROUND/AIM: The effect of vitamin D on skin carcinogenesis is unclear. Vitamin D derivatives may protect against ultraviolet radiation (UVR)-induced DNA damage, immune suppression, and skin carcinogenesis. However, some epidemiological studies have reported an increased incidence of skin cancer associated with high serum vitamin D levels. We investigated the effect of vitamin D supplementation on serum, skin, and tumor vitamin D levels and on skin cancer development in hairless immunocompetent mice. MATERIALS AND METHODS: Female C3.Cg-Hrhr/TifBomTac immunocompetent mice (n=125) were randomly separated into five groups. Two groups received a high vitamin D3 diet (4.5 µg/day/mouse). One group received a medium vitamin D3 diet (2.3 µg/day/mouse). Two groups received a standard diet (0.045 µg/day/mouse). Three standard erythema doses of UVR were given three times per week to three groups. RESULTS: Animals on a high vitamin D3 diet had ~150-fold higher serum vitamin D3 levels (p=0.00016) and 3-fold higher serum 25-hydroxyvitamin D3 [25(OH)D3] levels (p=0.00016) than those on a standard diet. For mice on the medium vitamin D3 diet, serum vitamin D3 and 25(OH)D3 levels were 18-fold and 2.3-fold higher than for the standard diet, respectively (p=0.00016). All UVR-exposed mice developed tumors. Vitamin D3 levels were lower in the tumor than the skin (p<0.0001). High and medium supplementation with vitamin D3 did not affect tumor development (p>0.05). CONCLUSION: In mice, vitamin D levels in the serum, skin, and tumors were augmented by supplementation, but this did not affect the development of UVR-induced skin tumors.

Detection of cutaneous malignant melanoma using RNA sampled by tape strips: A study protocol.

BACKGROUND: Cutaneous malignant melanoma (CMM) is curable if detected in its early stages. However, the clinical recognition of CMM is challenging. An American research group has shown promising results in detecting CMM based on RNA profiles sampled from suspicious lesions with tape strips. We aim to further develop this technique and validate if RNA profiles sampled with tape strips can detect CMM. METHODS: This prospective cohort study will include approximately 200 lesions clinically suspected of CMM requiring surgical removal. Tape stripping of the lesions will be performed just before surgical excision. Subsequently, RNA on the tape strips is analyzed using quantitative real-time polymerase chain reaction with TaqMan technology. The results are combined into a binary outcome where positive indicates CMM and negative indicates no CMM. The histopathological diagnosis of the lesions will be used as the gold standard. The main outcome is the results of the RNA test and the histopathological diagnosis, which, combined, provide the sensitivity and specificity of the test. DISCUSSION: The accuracy of the clinical examination in CMM diagnostics is limited. This clinical trial will explore the ability to use RNA analysis to improve the management of suspicious lesions by enhancing early diagnostic accuracy. Hopefully, it can reduce the number of benign lesions being surgically removed to rule out CMM and decrease patient morbidity. TRIAL REGISTRATION: The project was approved by The Committee on Health Research Ethics of the Capital Region of Denmark (H-15010559) and registered at the Danish Data Protection Agency (BFH-2015-065).

Bringing the gentle properties of daylight photodynamic therapy indoors: A systematic review of efficacy and safety.

Classic photodynamic therapy (PDT) is an effective, but painful, treatment of actinic keratosis (AK). Daylight PDT with simultaneous activation of protoporphyrin IX during its formation is almost painless and as effective. Recent studies suggest that this gentle simultaneous activation can be performed indoors by replacing daylight with a suitable light source. We aimed to systematically review efficacy and tolerability of indoor gentle PDT of AKs using various light sources. We systematically searched MEDLINE, Embase, and the Cochrane Library for clinical studies of treatment efficacy or adverse events. Indoor gentle PDT consists of application of methyl aminolevulinate or 5-aminolevulinic acid on the skin prior to long time illumination, starting no later than one hour after application. Fifteen studies met the selection criteria, enrolling 518 patients with more than 5,000 AKs undergoing indoor gentle PDT. The studies mainly included thin AKs comprised of 8 uncontrolled studies and 7 randomized controlled trials (RCT) of which 3 were designed as non-inferiority RCTs. Results from both controlled and uncontrolled trials indicated good treatment tolerability with very low pain scores like those of daylight PDT. Reduction of AK lesions 3 months after indoor gentle PDT in RCTs ranged from 52% to 79%, which is comparable to classic and daylight PDT. All 3 non-inferiority RCTs reported that indoor gentle PDT was non-inferior in terms of efficacy to classic PDT. The included studies used varying treatment protocols with different pretreatments, incubation time, light sources, and irradiation time. No standard protocol for indoor gentle PDT exists yet.

Identifying the psychosocial predictors of ultraviolet exposure to the face in patients with xeroderma pigmentosum: a study of the behavioural factors affecting clinical outcomes in this genetic disease.

BACKGROUND: For patients with xeroderma pigmentosum (XP), the main means of preventing skin and eye cancers is extreme protection against ultraviolet radiation (UVR), particularly for the face. We have recently developed a methodology for objectively measuring photoprotection behaviour ('UVR dose to facial skin') and have found that the degree of photoprotection varies greatly between patients with XP. We have previously identified factors affecting photoprotection behaviour in XP using a subjective measure of photoprotection. Here, we have used this objective methodology to identify the factors which determine photoprotection behaviour in XP. METHODS: We studied 29 psychological, social, demographic and clinical variables in 36 patients with XP. We have previously objectively measured UVR protection (by measuring the dose of UVR reaching the skin of the face over a 3-week period) in these patients. Here, we use linear mixed-effects model analysis to identify the factors which lead to the differences in degree of photoprotection observed in these patients. RESULTS: Psychosocial factors accounted for as much of the interindividual variation in photoprotection behaviour (29%) as demographic and clinical factors (24%). Psychosocial factors significantly associated with worse UVR protection included: automaticity of the behaviours, and a group of beliefs and perceptions about XP and photoprotection known to associate with poor treatment adherence in other diseases. CONCLUSIONS: We have identified factors contributing to poor photoprotection in XP. Identifying these potentially reversible psychosocial features has enabled us to design an intervention to improve photoprotection in patients with XP, aiming to prevent skin and eye cancers in these patients.

Topical Brimonidine Delays Ultraviolet Radiation-Induced Squamous Cell Carcinoma in Hairless Mice.

We investigated whether topical brimonidine delayed or enhanced the development of squamous cell carcinoma (SCC) when ultraviolet radiation (UVR) was applied to a well-established murine model. Hairless female mice (n = 125) were randomized into five groups and treated as follows: 1% brimonidine cream before UVR (Group 1), 0.33% brimonidine gel before UVR (Group 2), 1% brimonidine cream after UVR (Group 3), UVR only (control; Group 4) and 1% brimonidine cream only (control; Group 5). For each animal, the first four tumors were recorded and followed until three tumors reached 4 mm or one tumor reached 12 mm in diameter. All animal experiments continued for up to 365 days or until death. Application of 1% brimonidine cream before UVR delayed tumor development relative to control mice treated with UVR alone (P = 0.000006). However, when 0.33% brimonidine gel was applied before UVR (P = 0.313) or 1% brimonidine cream was applied after UVR (P = 0.252), there was no significant delay in tumor development relative to control mice treated with UVR alone. The development of the second and third tumors followed a similar pattern. Topical 1% brimonidine cream applied before UVR exposure delayed SCC development in hairless mice. In contrast, when brimonidine was applied after UVR there was no significant delay in tumor development. These results suggest that the 1% brimonidine cream probably absorbed the UVR, and therefore, a delay in tumor formation was only seen when brimonidine was applied before irradiation. However, there can be multiple reasons for this delay in photocarcinogenesis.

Cimetidine for erythropoietic protoporphyria.

BACKGROUND: Erythropoietic protoporphyria (EPP) is caused by deficiency of the enzyme converting protoporphyrin IX (PpIX) into heme resulting in accumulation of PpIX; leading to photosensitivity and liver toxicity. Cimetidine might inhibit δ-aminolevulinic acid synthase influencing the heme biosynthesis. We present cases with EPP treated with cimetidine at our department, and a literature review. METHODS: Systematic searches were performed to identify literature describing EPP patients treated with cimetidine. On that ground we treated EPP patients with cimetidine through spring and summer in 2020 and 2021 at our department. Their erythrocyte PpIX level and standard blood and liver parameters were collected before and during 4 months of treatment. Using a questionnaire, patients were asked about change in photosensitivity, side effects, and whether they would like to resume treatment in the spring of 2022. RESULTS: Literature searches identified 9 patients treated with cimetidine. Four were outpatients reporting decreased photosensitivity. At our department 18 outpatients started treatment. Fifteen used oral cimetidine daily for 4 months or more providing a significant decrease in erythrocyte PpIX with a median of 20% (range: -18% to 53%) after 4 months. Eleven of the 15 patients reported a decrease in photosensitivity during treatment, 3 patients were unsure, and 1 patient experienced unchanged photosensitivity. Only mild side effects were reported. Fourteen patients requested to resume treatment in the spring of 2022. CONCLUSIONS: These cases suggest that cimetidine can lower erythrocyte PpIX in patients with EPP.

Treatment of Familial Benign Chronic Pemphigus With Superficial Radiotherapy.

IMPORTANCE: Hailey-Hailey disease (HHD) is a chronic genodermatosis with recurrent vesicles and erosions mainly in the intertriginous areas. Hailey-Hailey disease severely affects patient quality of life. Standard treatments attempt to control the flares, but often do not result in long-term remission of the disease. OBJECTIVE: To describe outcomes of treatment with superficial radiotherapy (SR) for severe treatment-refractory HHD. DESIGN, SETTING, AND PARTICIPANTS: This retrospective case-series included 13 patients with severe HHD with a mean (SD) duration of 24 (14) years whose treatments with SR and follow-up were conducted at the Department of Dermatology at Bispebjerg University Hospital (Copenhagen, Denmark) from January 2015 to April 2021. INTERVENTIONS: Patients were treated with SR (20 kilovolt; 8 fractions of 2 gray was equal to 1 cycle) with a total dose of 16 gray in each treatment cycle. Patients received 1 to 6 treatment cycles with 1 to 5 separate body areas treated in each cycle. Sixty-two separate body areas were treated with SR. MAIN OUTCOMES AND MEASURES: Complete long-term remission, defined as no relapse during follow-up of at least 12 months. RESULTS: For the 13 participants (mean [SD] age, 52 [18] years; 8 women [62%]), 56 of 62 treated areas (90%) achieved long-term remission, and the mean (SD) follow-up was 32 (12) months for the successfully treated areas. Nine of 13 patients (69%) responded with complete remission of all treated areas after the first treatment cycle and an additional 3 patients experienced complete remission after the second SR cycle. One patient with partial remission in 1 of 2 treated skin areas experienced such an improvement in HHD that they chose to abstain from retreatment. The treatment was followed by severe inflammation lasting for up to 1 month followed by temporary slight hyperpigmentation of the treated areas. The average Dermatology Life Quality Index score before treatment with SR was 22 (the disease having extremely large effect on the patient's life) and decreased to an average of 3 (small effect on the patient's life) after treatment with SR. CONCLUSIONS AND RELEVANCE: The results of this case series suggest that treatment with SR was associated with remission in patients with severe HHD and may provide a long-term improvement of treated skin areas.

The effect of vitamin D recommendations on serum 25-hydroxyvitamin D level in patients with erythropoietic protoporphyria.

OBJECTIVES: Patients with erythropoietic protoporphyria (EPP) avoid sun exposure owing to photosensitivity. For decades, sun-avoiding Danes have been recommended daily vitamin D supplements all year. We offered our EPP patients serum 25-hydroxyvitamin D (25(OH)D) monitoring, and counseling if their level was low. We aimed to investigate the effect of the general recommendation and counseling on 25(OH)D status in patients attending our clinic. Additionally, the 25(OH)D status of our EPP patients was compared to that of British patients with EPP not taking vitamin D supplements and with that of the general Danish population. METHODS: Forty-six Danish patients with EPP had 25(OH)D measured in 721 blood samples collected between 2003 and 2021. Dates of individual counseling were noted. Data on British patients with EPP and the general Danish population were extracted from previous publications. RESULTS: Our patients had higher 25(OH)D levels than British patients with EPP not taking vitamin D supplements, but the recommendations did not elevate their 25(OH)D levels to that of the general Danish population. Overall, 17.5% of the 25(OH)D measurements in our EPP patients were below 30 nmol/L (deficiency) and 29.4% were between 30 and 50 nmol/L (insufficiency). Patients were monitored for a median of 11 y. Thirty-one patients had a total of 74 vitamin D counseling sessions, providing an increase in 25(OH)D of about 18 nmol/L the year after. However, many patients repeatedly developed insufficiency. CONCLUSIONS: This study documents the positive effect of vitamin D recommendations on serum 25(OH)D in patients with EPP. Follow-up on vitamin D status and recommendations is essential to increase 25(OH)D levels.

Distribution of protoporphyrin IX in erythrocytes in a case of acquired erythropoietic protoporphyria.

BACKGROUND: Erythropoietic protoporphyria (EPP) is a rare genetic photodermatosis caused by loss-of-function mutations in the gene for ferrochelatase leading to accumulation of the fluorescent protoporphyrin IX (PpIX) in erythrocytes. The mutations are most often inherited mutations present in all cells causing inherited EPP. In very rare cases EPP are acquired in association with myelodysplastic syndromes or myeloproliferative neoplasms, conditions with genetic instability. CASE REPORT: We report a case of acquired EPP in association with hematological disease. We followed erythrocyte PpIX concentration over a year and measured PpIX fluorescence in individual erythrocytes in a blood sample from the case using flow cytometry. The major proportion of erythrocytes did not fluoresce (84%), whereas 13% contained low PpIX fluorescence, 1% contained medium fluorescence, and 2% contained high fluorescence. DISCUSSION: Our observation of the very skewed PpIX distribution in erythrocytes supports the description that acquired EPP is caused by a somatic mutation effecting a clone of hematopoietic cells.

Actinic keratoses contiguous with squamous cell carcinomas are mostly non-hyperkeratotic and with severe dysplasia.

AIMS: Actinic keratosis (AK) is a precursor of cutaneous squamous cell carcinoma (SCC). No validated parameters can predict which AKs will progress into SCCs, but especially thick AKs are under suspicion. The clinical and histopathological thickness of AKs is strongly correlated. This study aimed to investigate the thicknesses and degree of dysplasia of AKs contiguous with SCCs assuming these AKs represent the AKs that have undergone malignant transformation. METHODS: Files of the Pathology Department, Hospital of Southern Jutland, Denmark, were reviewed. 111 cases met the inclusion criteria: a skin biopsy containing an invasive SCC. All SCCs merged with an AK at the edge. Degree of dysplasia, epidermal thickness and stratum corneum thicknesses of AKs were measured. RESULTS: All AKs showed severe dysplasia. Most AKs had a stratum corneum thickness under 0.1 mm and an epidermal thickness under 0.5 mm, corresponding to clinically thin and non-hyperkeratotic AKs. CONCLUSIONS: Our result suggests malignant progression potential of AKs regardless of thickness.