Athena speciality certificate examination case for photodermatology.

This Athena case describes a young girl with a 2-year history of episodic pruritic erythematous papules on her right cheek, which coalesced to form a plaque. The eruption later recurred, involving the left cheek, nose and upper arms.

Potential harm to the skin from unfiltered krypton chloride 'far-ultraviolet-C' lamps, even below an occupational exposure limit.

Ultraviolet-C (UVC) radiation can effectively inactivate pathogens on surfaces and in the air. Due to the potential for harm to skin and eyes, human exposure to UVC should be limited within the guideline exposure limits produced by the International Commission on Non-Ionising Radiation Protection (ICNIRP) or the American Conference of Governmental Industrial Hygienists (ACGIHs). Both organisations state an effective spectrally weighted limit of 3 mJ cm-2, although the spectral weighting factors of the two organisations diverged following a revision of the ACGIH guidelines in 2022. Using existing published human exposure data, the effective spectrally weighted radiant exposure was calculated for both unfiltered and filtered (to reduce UV emissions above 230 nm) krypton chloride (KrCl*) excimer lamps. The effective radiant exposure of the filtered KrCl* lamp was greater than 3 mJ cm-2when applying ICNIRP or either of the revised ACGIH spectral weightings. This indicates that both guidelines are appropriately conservative for this specific lamp. However, the effective radiant exposure of the unfiltered KrCl* lamp was as low as 1 mJ cm-2with the revised ACGIH weighting function that can be applied to the skin if the eyes are protected. Erythema has therefore been directly observed in a clinical study at an exposure within the revised ACGIH guideline limits. Extrapolating this information means that a mild sunburn could be induced in Fitzpatrick skin types I and II if that particular ACGIH weighting function were applied and an individual received an effective exposure of 3 mJ cm-2. Whilst it is improbable that such an effect would be seen in current deployment of KrCl* lamp technology, it does highlight the need for further research into skin sensitivity and irradiance-time reciprocity for UVC wavelengths.

Phototherapy for atopic eczema.

BACKGROUND: Atopic eczema (AE), also known as atopic dermatitis, is a chronic inflammatory skin condition that causes significant burden. Phototherapy is sometimes used to treat AE when topical treatments, such as corticosteroids, are insufficient or poorly tolerated. OBJECTIVES: To assess the effects of phototherapy for treating AE. SEARCH METHODS: We searched the Cochrane Skin Specialised Register, CENTRAL, MEDLINE, Embase, and ClinicalTrials.gov to January 2021. SELECTION CRITERIA: We included randomised controlled trials in adults or children with any subtype or severity of clinically diagnosed AE. Eligible comparisons were any type of phototherapy versus other forms of phototherapy or any other treatment, including placebo or no treatment. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodology. For key findings, we used RoB 2.0 to assess bias, and GRADE to assess certainty of the evidence. Primary outcomes were physician-assessed signs and patient-reported symptoms. Secondary outcomes were Investigator Global Assessment (IGA), health-related quality of life (HRQoL), safety (measured as withdrawals due to adverse events), and long-term control. MAIN RESULTS: We included 32 trials with 1219 randomised participants, aged 5 to 83 years (mean: 28 years), with an equal number of males and females. Participants were recruited mainly from secondary care dermatology clinics, and study duration was, on average, 13 weeks (range: 10 days to one year). We assessed risk of bias for all key outcomes as having some concerns or high risk, due to missing data, inappropriate analysis, or insufficient information to assess selective reporting. Assessed interventions included: narrowband ultraviolet B (NB-UVB; 13 trials), ultraviolet A1 (UVA1; 6 trials), broadband ultraviolet B (BB-UVB; 5 trials), ultraviolet AB (UVAB; 2 trials), psoralen plus ultraviolet A (PUVA; 2 trials), ultraviolet A (UVA; 1 trial), unspecified ultraviolet B (UVB; 1 trial), full spectrum light (1 trial), Saalmann selective ultraviolet phototherapy (SUP) cabin (1 trial), saltwater bath plus UVB (balneophototherapy; 1 trial), and excimer laser (1 trial). Comparators included placebo, no treatment, another phototherapy, topical treatment, or alternative doses of the same treatment. Results for key comparisons are summarised (for scales, lower scores are better): NB-UVB versus placebo/no treatment There may be a larger reduction in physician-assessed signs with NB-UVB compared to placebo after 12 weeks of treatment (mean difference (MD) -9.4, 95% confidence interval (CI) -3.62 to -15.18; 1 trial, 41 participants; scale: 0 to 90). Two trials reported little difference between NB-UVB and no treatment (37 participants, four to six weeks of treatment); another reported improved signs with NB-UVB versus no treatment (11 participants, nine weeks of treatment). NB-UVB may increase the number of people reporting reduced itch after 12 weeks of treatment compared to placebo (risk ratio (RR) 1.72, 95% CI 1.10 to 2.69; 1 trial, 40 participants). Another trial reported very little difference in itch severity with NB-UVB (25 participants, four weeks of treatment). The number of participants with moderate to greater global improvement may be higher with NB-UVB than placebo after 12 weeks of treatment (RR 2.81, 95% CI 1.10 to 7.17; 1 trial, 41 participants). NB-UVB may not affect rates of withdrawal due to adverse events. No withdrawals were reported in one trial of NB-UVB versus placebo (18 participants, nine weeks of treatment). In two trials of NB-UVB versus no treatment, each reported one withdrawal per group (71 participants, 8 to 12 weeks of treatment). We judged that all reported outcomes were supported with low-certainty evidence, due to risk of bias and imprecision. No trials reported HRQoL. NB-UVB versus UVA1 We judged the evidence for NB-UVB compared to UVA1 to be very low certainty for all outcomes, due to risk of bias and imprecision. There was no evidence of a difference in physician-assessed signs after six weeks (MD -2.00, 95% CI -8.41 to 4.41; 1 trial, 46 participants; scale: 0 to 108), or patient-reported itch after six weeks (MD 0.3, 95% CI -1.07 to 1.67; 1 trial, 46 participants; scale: 0 to 10). Two split-body trials (20 participants, 40 sides) also measured these outcomes, using different scales at seven to eight weeks; they reported lower scores with NB-UVB. One trial reported HRQoL at six weeks (MD 2.9, 95% CI -9.57 to 15.37; 1 trial, 46 participants; scale: 30 to 150). One split-body trial reported no withdrawals due to adverse events over 12 weeks (13 participants). No trials reported IGA. NB-UVB versus PUVA We judged the evidence for NB-UVB compared to PUVA (8-methoxypsoralen in bath plus UVA) to be very low certainty for all reported outcomes, due to risk of bias and imprecision. There was no evidence of a difference in physician-assessed signs after six weeks (64.1% reduction with NB-UVB versus 65.7% reduction with PUVA; 1 trial, 10 participants, 20 sides). There was no evidence of a difference in marked improvement or complete remission after six weeks (odds ratio (OR) 1.00, 95% CI 0.13 to 7.89; 1 trial, 9/10 participants with both treatments). One split-body trial reported no withdrawals due to adverse events in 10 participants over six weeks. The trials did not report patient-reported symptoms or HRQoL. UVA1 versus PUVA There was very low-certainty evidence, due to serious risk of bias and imprecision, that PUVA (oral 5-methoxypsoralen plus UVA) reduced physician-assessed signs more than UVA1 after three weeks (MD 11.3, 95% CI -0.21 to 22.81; 1 trial, 40 participants; scale: 0 to 103). The trial did not report patient-reported symptoms, IGA, HRQoL, or withdrawals due to adverse events. There were no eligible trials for the key comparisons of UVA1 or PUVA compared with no treatment. Adverse events Reported adverse events included low rates of phototoxic reaction, severe irritation, UV burn, bacterial superinfection, disease exacerbation, and eczema herpeticum. AUTHORS' CONCLUSIONS: Compared to placebo or no treatment, NB-UVB may improve physician-rated signs, patient-reported symptoms, and IGA after 12 weeks, without a difference in withdrawal due to adverse events. Evidence for UVA1 compared to NB-UVB or PUVA, and NB-UVB compared to PUVA was very low certainty. More information is needed on the safety and effectiveness of all aspects of phototherapy for treating AE.

Development of a Predictive Monte Carlo Radiative Transfer Model for Ablative Fractional Skin Lasers.

It is possible to enhance topical drug delivery by pretreatment of the skin with ablative fractional lasers (AFLs). However, the parameters to use for a given AFL to achieve the desired depth of ablation or the desired therapeutic or cosmetic outcome are hard to predict. This leaves open the real possibility of overapplication or underapplication of laser energy to the skin. In this study, we developed a numerical model consisting of a Monte Carlo radiative transfer (MCRT) code coupled to a heat transfer and tissue damage algorithm. The simulation is designed to predict the depth effects of AFL on the skin, verified with in vitro experiments in porcine skin via optical coherence tomography (OCT) imaging. Ex vivo porcine skin is irradiated with increasing energies (50-400 mJ/pixel) from a CO2 AFL. The depth of microscopic treatment zones is measured and compared with our numerical model. The data from the OCT images and MCRT model complement each other well. Nonablative thermal effects on surrounding tissue are also discussed. This model, therefore, provides an initial step toward a predictive determination of the effects of AFL on the skin. Lasers Surg. Med. © 2020 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC.

Tomato Phytonutrients Balance UV Response: Results from a Double-Blind, Randomized, Placebo-Controlled Study.

BACKGROUND: Our previous double-blinded, placebo-controlled cross-over study indicated that a nutritional supplement named lycopene-rich tomato nutrient complex (TNC) can protect from UVA1-induced (340-400 nm) and UVA- (320-400 nm)/UVB-induced (280-320 nm) upregulation of molecular markers associated with oxidative stress, inflammation, and ageing. OBJECTIVES: in the current double-blind, randomized, placebo-controlled multicenter study, we analyze whether a similar, synergistic carotenoid-rich TNC can protect from broadband UVB-induced threshold erythema formation assessed as increase in minimal erythemal dose (MED) reading, the intensity of erythema formation, and the upregulation of molecular markers associated with inflammation and immunosuppression, and whether this correlates with carotenoid blood levels. METHODS: One hundred and forty-nine healthy volunteers were randomized to two groups and subjected to a 5-week washout phase, followed by a 12-week treatment phase receiving either 15 mg lycopene, 5.8 mg phytoene and phytofluene, 0.8 mg ß-carotene, 5.6 mg tocopherols from tomato extract, and 4 mg carnosic acid from rosemary extract per day or placebo made from medium-chain triglycerides. At the end of each phase, MED determination, UVB irradiation, chromametry, biopsies, and blood samples were undertaken. RESULTS: The active supplement was well tolerated. Interestingly, no significant difference was seen in the MED between the active-supplement and placebo groups, as determined by visual grading by expert assessors. Of note, the carotenoid-containing supplement significantly protected against UVB-induced erythema formation measured as Δa* after the intervention minus Δa* after the washout phase as compared to the placebo. Moreover, intake of the active supplement significantly protected against UVB-induced upregulation of IL6 and TNFα as compared with the intake of placebo. Lastly, carotenoid plasma levels were significantly increased. CONCLUSION: This well-tolerated carotenoid-containing supplement significantly protected against UVB-induced erythema formation and upregulation of proinflammatory cytokines in healthy volunteers.

Drug and chemical induced photosensitivity from a clinical perspective.

Drug photosensitivity is a relatively common occurrence and a range of mechanisms may be involved. Some of these mechanisms will be discussed, including the most common, that of drug phototoxicity. Different types of photosensitivity are addressed with respect to clinical presentation, mechanisms and additionally the contribution to our understanding through clinically directed investigations and regulatory requirements. Repeated controlled therapeutic use of drug phototoxicity, with psoralen-UVA (PUVA) photochemotherapy and photodynamic therapy (PDT) will also be discussed. Finally, the potential for drug-induced photocarcinogenesis will also be covered.

Structured Expert Consensus on Actinic Keratosis: Treatment Algorithm Focusing on Daylight PDT.

BACKGROUND: A practical and up-to-date consensus among experts is paramount to further improve patient care in actinic keratosis (AK). OBJECTIVES: To develop a structured consensus statement on the diagnosis, classification, and practical management of AK based on up-to-date information. METHODS: A systematic review of AK clinical guidelines was conducted. This informed the preparation of a 3-round Delphi procedure followed by a consensus meeting, which combined the opinions of 16 clinical experts from 13 countries, to construct a structured consensus statement and a treatment algorithm positioning daylight photodynamic therapy (dl-PDT) among other AK treatment options. RESULTS: The systematic review found deficiencies in current guidelines with respect to new AK treatments such as ingenol mebutate and dl-PDT. The Delphi panel established consensus statements across definition, diagnosis, classification, and management of AK. While the diagnosis of AK essentially rests on the nature of lesions, treatment decisions are based on several clinical and nonclinical patient factors and diverse environmental attributes. Participants agreed on ranked treatment preferences for the management of AK and on classifying AK in 3 clinical situations: isolated AK lesions requiring lesion-directed treatment, multiple lesions within a small field, and multiple lesions within a large field, both requiring specific treatment approaches. Different AK treatment options were discussed for each clinical situation. CONCLUSIONS: The results provide practical recommendations for the treatment of AK, which are readily transferable to clinical practice, and incorporate the physician's clinical judgement. The structured consensus statement positioned dl-PDT as a valuable option for patients with multiple AKs in small or large fields.

Daylight photodynamic therapy in Scotland.

Chronic sun-induced dysplastic skin changes (actinic keratoses) are extremely common in fair-skinned people in Scotland. These changes are a major cause of morbidity and may develop into skin cancer. Actinic keratoses are often extensive and pose a therapeutic challenge as field-directed treatment is required for chronic disease management. One such treatment approach is hospital-based photodynamic therapy, which is a well-established treatment in Scotland for actinic keratoses, using a photosensitiser pro-drug and red LED light irradiation. However, photodynamic therapy using daylight as the activating light source is increasingly and effectively used in continental Europe, but had not been explored in Scotland until we initiated this in 2013. We report our experience of daylight photodynamic therapy in 64 patient-treatment courses and demonstrate that this can be an effective, well-tolerated treatment, which is liked by patients. Our most recent data show that most patients (73%) achieved clearance or at least a good response to treatment and had high levels of satisfaction with daylight photodynamic therapy. Daylight exposure measurements indicated that treatment is feasible in Scotland between April to September. Daylight photodynamic therapy is an important advancement in treatment options for Scottish patients with extensive pre-cancerous field changes and provides opportunities for home-based treatment and increased efficiency of photodynamic therapy services.

The effect of 222-nm UVC phototesting on healthy volunteer skin: a pilot study.

BACKGROUND: Frequent topical antiseptic use to hands is now common in healthcare and other work environments. Inevitably, the use of such antiseptics will present an occupational risk for irritancy and allergic dermatitis. New, less irritant and even non-chemical antimicrobial approaches are under investigation. METHODS: A Sterilray disinfectant source (222 nm) conventionally used to sterilize equipment and work surfaces was assessed for tolerability in human skin. Using an escalating dosage study methodology, four skin phototype I and II healthy volunteers had their minimal erythema dose (MED) determined. Punch biopsies of irradiated sites were stained for cyclobutane pyrimidine dimers (CPD). The degree of CPD was compared with that in biopsies from unexposed skin and from areas exposed to UVB (280-315 nm) radiation. RESULTS: Calibrated spectral measurements revealed emission at a peak wavelength of 222 nm with 97% emission at wavelengths less than 250 nm. At low doses below the threshold bacteriostatic effect, the source was capable of inducing both erythema and CPD formation in human skin. In two individuals, cells in the basal layer were not shielded by the overlying tissue as indicated by the presence of CPD. CONCLUSION: The source showed an erythemogenic or CPD potential at lower doses than those required to reach the reported threshold bacteriostatic effect.

Porphyria cutanea tarda in Scotland: underlying associations and treatment approaches.

BACKGROUND: Despite its rarity, porphyria cutanea tarda (PCT) is globally recognized as the most common form of cutaneous porphyria. This study aims to review the underlying associations and treatment of PCT in Scotland. METHODS: We retrospectively reviewed data on 27 patients diagnosed with PCT between 1987 and 2022 at the Scottish Cutaneous Porphyria Service. RESULTS: Males slightly predominated (66.7%). The mean ± standard deviation (SD) age at diagnosis was 55.6 ± 12.5 years. Common associated factors were heavy alcohol intake (88.5%), genetic hemochromatosis (72%), smoking (45.5%), and hepatitis C virus infection (16%). Most had multiple associated factors (70.4%). Patients with genetic hemochromatosis with the C282Y genotype exhibited higher median transferrin saturation (69.5 vs. 35, P = 0.004) and ferritin levels (observed in males only) (1175 vs. 339; P = 0.014) than those with the H636D genotype. Most (52%) received combination therapy of venesection and antimalarials, followed by venesection monotherapy (32%) and antimalarial monotherapy (16%). Overall, 95.2% achieved biochemical improvement. Median time to improvement was 7, 5, and 9 months with venesection, antimalarial, and combined treatments, respectively (P = 0.173). Biochemical remission was achieved in 50% of patients. Remission occurred in 2/4 of patients with antimalarial monotherapy (median time 19 months) and 9/13 patients with combined treatment (median time 26 months). Biochemical relapse was found in three patients, all of whom received combination therapy. CONCLUSION: Excess alcohol intake and genetic hemochromatosis were the most common underlying associations with PCT in our Scottish cohort. Treatment for PCT should be individualized, and long-term follow-up is needed to monitor for disease relapse.

Modelling fluorescence in clinical photodynamic therapy.

Understanding the interactions of non-ionizing radiation with living organisms has been the focus of much research over recent decades. The complex nature of these interactions warrants development of theoretical and experimental studies to gain an insight into predicting and monitoring the success of photodynamic therapy (PDT) protocols. There is a major impetus towards evidence-based recommendations for patient diagnosis, treatment and management. Knowledge of the biophysical aspects of PDT is important for improving dosimetry protocols. Fluorescence in clinical PDT may be used to detect and diagnose pre-malignant and malignant conditions, while photobleaching can monitor changes in fluorescence during treatment. Combining empirical fluorescence photobleaching clinical data with computational modelling enables clinical PDT dosimetry protocols to be investigated with a view to optimising treatment regimes. We will discuss how Monte Carlo radiation transfer (MCRT) modelling has been intercalated in the field of fluorescence detection and PDT. In this paper we highlight important aspects of basic research in PDT by reporting on the current utilisation of fluorescence in clinical PDT from both a clinical and theoretical perspective. Understanding and knowledge of light propagation in biological tissue from these perspectives should have a positive impact on treatment planning.

Characterization of a human keratinocyte HaCaT cell line model to study the regulation of CYP2S1.

CYP2S1 is an extrahepatic cytochrome P450 (P450) that shows marked individuality in constitutive and inducible expression. CYP2S1 mRNA expression is increased in psoriasis and by treatments for psoriasis, including retinoids and UV radiation, although endogenous substrates remain poorly characterized. Because previous model systems have overexpressed modified CYP2S1 in bacteria, human HaCaT keratinocyte cells were screened for constitutive and regulatable CYP2S1 expression and CYP2S1 activity in HaCaT cells compared with a novel Chinese hamster ovary (CHO)-based cell line engineered to stably coexpress CYP2S1 and NADPH cytochrome P450 reductase. Constitutive mRNA expression for CYP2S1 and additional P450s, retinoid acid receptors (RARα, RARß, RARγ), and retinoid X receptors (RXRα, RXRß and RXRγ) was assessed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis in HaCaT cells. Cells were then exposed to retinoids or to UV radiation (UVR), and changes in CYP2S1 mRNA abundance were further examined by qRT-PCR analysis. P450 expression in HaCaT cells was similar to human skin, with abundant CYP2S1 expression. RARα and RARγ (but not RARß) and all RXR isoforms were also detectable. All-trans retinoic acid (atRA) induced CYPS1 mRNA expression more potently than 9-cis RA or 13-cis RA. P450-dependent atRA metabolism was demonstrated in HaCaT cells, with a very similar metabolite profile to that produced by our CYP2S1-expressing CHO cells. CYP2S1 mRNA expression was also induced by UVR, more potently than CYP1B1, a known UVR-inducible P450. Our results demonstrate regulatable and functional CYP2S1 expression in HaCaT cells, thus identifying a human cell line model with utility for further analysis of CYP2S1 regulation and substrate specificity.

Ambulatory photodynamic therapy using low irradiance inorganic light-emitting diodes for the treatment of non-melanoma skin cancer: an open study.

BACKGROUND/PURPOSE: Conventional photodynamic therapy (PDT) can be inconvenient and uncomfortable. We studied low irradiance PDT using an ambulatory inorganic light-emitting diode. METHODS: Fifty-three patients with 61 lesions [superficial basal cell carcinoma (n = 30), Bowen's disease (n = 30), and actinic keratosis (AK; n = 1)] were studied. Two treatments of ambulatory PDT were undertaken 1 week apart (one treatment for AK). Clinical response was determined at 3 months, and the treatment cycle was repeated if there was residual disease. The endpoints assessed were pain during treatment (numerical rating scale (NRS); 0-10) and outcome at 1 year. Twenty-three of these patients also received conventional PDT to separate lesions. RESULTS: The median NRS pain scores during first and second treatment were 2 (range 0-9) and 4 (0-9), respectively. Lesion clearance rate at 1 year after ambulatory PDT was 84% (21/25 lesions in 22 patients). Of the twenty-three patients treated with both ambulatory and conventional PDT, the median NRS was 1 (0-7) and 5 (1.5-9), respectively, with most patients preferring ambulatory PDT. CONCLUSION: Ambulatory PDT is effective for superficial non-melanoma skin cancer, with 1 year clearance rates comparative to conventional PDT. Low irradiance ambulatory PDT may be less painful and more convenient than conventional PDT.