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Background: There is limited literature on efficacy in 5-aminolaevulinic acid (BF-200 ALA) and methyl-5-aminolaevulinate (MAL) for superficial basal cell carcinoma (sBCC). Aims: To investigate the efficacy and safety of PDT in sBCC. Methods: Analytical observational study between January 2014 and January 2017. Follow-up at 12, 24 and 52 weeks. Lesions were treated with one BF-200 ALA-PDT or MAL-PDT cycle of two sessions in one week. A second treatment cycle, with the same photosensitizer precursor, was performed in cases of clinical persistence at 12 weeks. Results: A total of 22 patients (30 lesions) were enrolled in the study. By sex, 13 men and 9 women. Average age of 72,14 years. In the 12-month follow-up 15/16 lesions were resolved (93,75%) after one or two BF-200 ALA-PDT cycle and 7/14 lesions (50%) after one or two MAL-PDT cycles. In most patients, tolerance to the therapy was good or regular, with no differences between the two groups. No long-term adverse effects were reported. Limitations: The observational nature and the low number of patients. Conclusion: PDT is a safe and non-invasive treatment option in sBCC. Our results suggest a better response with BF-200 ALA-PDT over MAL-PDT, at 12 months of follow-up.

Background Photodynamic therapy (PDT) is a well-known and effective treatment for non-melanoma skin-cancer. Numerous studies have also shown its effectiveness in mycosis fungoides. The aim of the study was to analyse MF patients treated with PDT at the Dermatology Unit of Bologna University. Methods We retrospectively analysed MF patients treated with PDT over the last ten years. Each PDT protocol consisted of the appliance for 3 h under an occlusive film dressing on each lesion of a one-mm-thick layer of 16% methyl aminolaevulinate (MAL) 160 mg/g cream (Metvix ® , Galderma, Paris, France). The cream was then removed and the skin was exposed to 630 nm red light from a diode lamp (Aktilite ® , Galderma Benelux, Rotterdam, the Netherlands), with a total radiation dose of 37 J/cm2 for 9 mins. A protocol of one session every month was scheduled. The treated lesions were clinically examined, before each treatment. Results Four cases, three male and one female, had been treated with PDT. Two patch lesions on the plantar area, one leg and the pubic area were treated. The number of PDT sessions ranged from 4 to 9. Two complete remissions and two partial remissions were observed. A low-to-mild burning sensation was reported during the treatment, and persisted over the next day; no further side effects were observed. Conclusions Our series shows that PDT can be considered an effective second-line treatment in patients characterised by a disease located in difficult-to-treat anatomical areas such as the feet and the pubic area.

Background Pulse photodynamic therapy (PDT) is carried out as classical PDT except that methyl aminolaevulinate (MAL) is removed after 30 min. Protoporphyrin IX (PpIX) accumulation becomes lower after 3 h in pulse-PDT than in classical PDT, but pulse-PDT still has full treatment effect on actinic keratosis (AK). The present study aimed to investigate when PpIX formation in classical PDT without curettage reaches the PpIX level in pulse-PDT with curettage in the skin of the face and scalp. Methods Fourteen patients with AKs in the face and scalp were included in this pilot study. Each patient had two fields randomly allocated to two different regimes: (i) continuing MAL incubation without prior curettage (−Cur) and (ii) 30 min MAL incubation after curettage (+Cur). The PpIX level in each field was measured with a hand-held fluorescence photometer every 30 min for 6 h after MAL application. No illumination was performed. Results The median PpIX level in the +Cur field after 3 h was 22 arbitrary units (AU), which represents the amount of PpIX that could have been photobleached after pulse-PDT with maximal treatment effect. After 3 h the median PpIX level in the −Cur field was 20 AU, which was not significantly different from the level in the +Cur field (p = 0.9). Conclusions We propose PDT without curettage as follows: 3 h of MAL incubation and subsequently sufficient illumination. The treatment effect of this regime should be tested to verify if curettage of the face and scalp area may be omitted in PDT.

An observational study was carried out in the photodynamic therapy (PDT) section of Fuenlabrada’s hospital (Madrid, Spain). Our goal was to investigate the efficacy and safety of PDT in Bowen’s disease (BD). Between June 2011-June 2017 171 patients (191 lesions) with diagnosis of BD were enrolled in the study (95 women and 76 men; average age of 74.31 years). Lesions were treated with one 5-aminolaevulinic acid (BF-200 ALA)-PDT or methyl-5-aminolaevulinate (MAL)-PDT cycle of two sessions in one week. A second treatment cycle was performed in cases of clinical persistence at 12 weeks. Our results showed that 47/55 lesions were resolved (84.75%) after one or two ALA-PDT cycle and 75/136 lesions (55.15%) after one or two MAL-PDT cycles, in the 12-month follow-up. In conclusion PDT is a safe and non-invasive treatment option in BD. In addition, our results suggest a better response with ALA-PDT over MAL-PDT. Limits: observational study with a limited number of patients.

Cutaneous squamous cell carcinoma (SCC) is the second most common skin cancer. Surgery remains the main stay of treatment, but some patients are not eligible for surgery and, more importantly, lesions at critical sites need nonsurgical approaches for tissue preservation. In this context, photodynamic therapy (PDT) has been extensively studied as noninvasive or minimally invasive treatment, and studies have shown promising results in terms of safety, efficacy, and cosmetic outcome. Also, studies have proposed different mechanism for its efficacy. However, human studies demonstrating its efficacy are limited in terms of sample size and tumor depth of invasion. Good results are mainly seen in case reports of microinvasive SCC, which is defined as SCC limited to papillary dermis. This inadequacy is due to inadequate penetration of topically applied photosensitizers through keratinized tumor surfaces. To overcome these hurdles, pretreatment with lasers or microneedles and encapsulation of photosensitizers into nanoparticles have been tried. Hence, the present article will discuss studies that have demonstrated the efficacy and safety of PDT for cutaneous SCC, studies that have postulated the mechanism of action of PDT, agents that have been used as PDT enhancers, and finally, the recent use of adjuvant therapy in combination with PDT.

BACKGROUND Topical photodynamic therapy (PDT) is a popular treatment modality in dermatology. The effect of PDT in epidermal cells depends on formation of protoporphyrin IX (PpIX) from 5-aminolevulinic acid (ALA). A variety of physiological changes in epidermal function occur with increasing age, but no studies have investigated whether PpIX formation is age-related. OBJECTIVES To investigate a possible relationship between age and PpIX formation. METHODS Methyl aminolaevulinate cream (MAL) and 5-ALA gel (BF-200 ALA) were applied to two identical fields on the forearm of 30 healthy volunteers for 24 h. The volunteers were divided into two age groups: a young group under 55 years (range 18-54) and an older group over 55 years (range 65-85). PpIX formation was measured noninvasively every hour from 1-5 h, and after 18, 21 and 24 h. Skin phototype, stratum corneum hydration and ultraviolet (UV) damage were also assessed. Treatment efficacy in relation to age was evaluated in 100 basal cell carcinomas (BCCs) treated with MAL-PDT. RESULTS Both photosensitizers induced significantly more PpIX formation in the younger group. Linear regression revealed a significant age-related decline in PpIX formation after the standard application time of 3 h (P < 0.001 for both treatments). Skin phototype, stratum corneum hydration and UV damage were not associated with PpIX formation. The treatment efficacy of BCCs 3 months after MAL-PDT was higher in young patients (P = 0.012). CONCLUSIONS PpIX formation in human skin declines with age. No explanation could be attributed to skin phototype, stratum corneum hydration or UV damage. The consequence might be reduced efficacy of PDT in the elderly.

Background/Objectives Solar (actinic) keratosis (AK) is an emergent concern worldwide and is associated with an increased risk of development of non-melanoma skin cancer, especially squamous cell carcinoma. Daylight-mediated photodynamic therapy (DL-PDT) using methyl aminolaevulinate cream has proved to be an effective, nearly painless, and more convenient alternative to conventional PDT for the treatment of AK. In a phase III, randomised, controlled trial performed in Australia, the mean irradiance (light intensity) received by patients during DL-PDT treatment, assessed via a spectroradiometer, was 305 W/m2 (min. 40 to max. 585 W/m2) with similar efficacy irrespective of intensity or dose. The objective of the present meteorological study was to assess the suitability of natural daylight to perform DL-PDT for the treatment of face and scalp AK during different periods of the year and different geographical locations and latitudes across Australia. Methods To determine daylight irradiance during a complete year in eight different geographical locations throughout Australia, we used meteorological software (Meteonorm, Meteotest, Bern, Switzerland), and available solar radiation and weather data from 1986–2005. Results The average daily irradiance remained within the levels (40–585 W/m2) measured during the clinical DL-PDT study in Australia, throughout the year and in all geographical locations investigated (yearly average from Darwin 548 W/m2 to Hobart 366 W/m2). Conclusions DL-PDT for the treatment of face and scalp AK in Australia can be performed effectively throughout the entire year as long as weather conditions permit daylight exposure and allow participants to remain under direct light for 2 h.

Summary Background Cutaneous leishmaniasis (CL) is endemic in Israel, with hundreds of new cases reported in recent years. Photodynamic therapy (PDT) is highly effective for treatment of CL, but requires equipment available only at specialized centres. Daylight-activated PDT (DA-PDT) abolishes the need for artificial light sources and allows the patient to administer the treatment with no professional assistance. Objectives The objective of this single-centre, open study was to establish proof of concept for the efficacy of DA-PDT in the treatment of CL using clinical, microbiological and molecular clearance as outcome measures. Methods Thirty-one patients with CL (11 Leishmania major and 20 Leishmania tropica) underwent DA-PDT. Fourteen patients were treated in the hospital garden under professional supervision and 17 patients underwent DA-PDT as a self-administered treatment modality at home. Following application of a thick layer of 16% methyl aminolaevulinate and 30-min occlusion, the lesions were exposed to daylight for 2·5 h. Treatment sessions were repeated at weekly intervals until clinical and microbiological cure. Control lesions were either treated with cryotherapy or left untreated. Results The overall cure rate for DA-PDT was 89% (intention-to-treat cure rate 77%); this was 86% for the hospital-based treatment group and 92% for the self-administered group. Conclusions DA-PDT proved to be effective in the treatment of CL caused by L. major and L. tropica. More patients were treated according to a self-administered protocol, suggesting that DA-PDT can be adopted even in technologically deprived countries where the majority of Leishmania infections are encountered.

Summary Background Photodynamic therapy (PDT) is an attractive therapy for nonmelanoma skin cancers and actinic keratoses (AKs). Daylight-mediated methyl aminolaevulinate PDT (daylight-PDT) is a simple and painless treatment procedure for PDT. All daylight-PDT studies have been performed in the Nordic countries. To be able to apply these results in other parts of the world we have to compare the daily protoporphyrin IX (PpIX) light dose in other countries with the PpIX light doses found in Nordic countries. Objectives To calculate where and when daylight-PDT of AKs was possible in six different geographical locations using ground stations measuring PpIX-weighted daylight doses. Methods PpIX-weighted daylight doses were measured using a dosimeter with a customer-specific photodiode with a detector sensitivity that mimics the PpIX absorption spectrum and measures in ‘PpIX doses’. The dosimeters were built into ground stations that were placed in six geographical locations measuring from July to December 2008. Temperature data for each location were obtained from the internet. The maximal ultraviolet (UV) index for Copenhagen was obtained for the measuring period of the dosimeters. Results If the PpIX light dose should be above 8 J cm−2 and the maximum temperature of the day at least 10 °C, it was possible to treat patients on nearly all days until the middle of September in Reykjavik and Oslo, until the last week of October in Copenhagen and Regensburg, until the middle of November in Turin and all year in Israel. Conclusions Where and when to perform daylight-PDT depends on the PpIX light dose and outdoor temperature. The PpIX light dose was influenced by the geographical location (latitude), weather condition and time of year. The UV index was not more suitable than temperature and weather to predict if the intensity of daylight would be sufficient for daylight-PDT.

Daylight photodynamic therapy with methyl aminolaevulinate (dlPDT) and ingenol mebutate gel (IMB) are approved therapeutic options for multiple actinic keratoses (AKs). The aim of this comparative, intra-patient, split-face, randomized clinical trial was to compare treatment outcomes of dlPDT and IMB.Two symmetrical contralateral areas of 25cm22 patients with a total of 311 AKs were enrolled. The mean pain VAS score was 3.55±1.82 with IMB and 2.05±0.72 with dlPDT (p0.01). The mean LSR score was 9.91±4.24 and 4.59±4.03 (p0.01), respectively. The mean days necessary for wound closure were 9.45±3.51 and 4.36±1.18days (p0.01), respectively. After 3 months, 119 lesions with IMB and 120 lesions with dlPDT were healed and the CR rate with IMB (75.8%) was non-inferior to the CR rate with dlPDT (77.9%). The comparisons of CR rates of grade I and II AKs did not show any inferiority for one treatment compared to the other. Eight patients (36.4%) had all lesions cleared with IMB and 7 (31.8%) with dlPDT (p=NS). The cosmetic outcome was better with dlPDT and 17 patients evaluated dlPDT as their preferred treatment.A 3days' treatment cycle with IMB and a single session of dlPDT had a similar efficacy for both grade I AKs and grade II AKs but dl PDT showed lower pain and inflammation scores, quicker wound closure, better cosmetic outcome and higher patients' preference.

Photodynamic therapy (PDT) of non-melanoma skin cancers currently carries failure rates of 10-40%. The optimal irradiation protocol is as yet unclear. Previous studies showed profound immunosuppression after PDT, which may compromise immune-mediated clearance of these antigenic tumors. Slower irradiation prevents immunosuppression in mice, and may be at least as effective as high-fluence-rate PDT in preliminary clinical trials. The photosensitizers 5-aminolaevulinic acid and/or methyl aminolaevulinate were applied to discrete areas on the backs of healthy Mantoux-positive volunteers, followed by narrowband red light irradiation (632 nm) at varied doses and fluence rates. Delayed type hypersensitivity (Mantoux) reactions were elicited at test sites and control sites to determine immunosuppression. Human ex vivo skin received low- and high-fluence-rate PDT and was stained for oxidative DNA photolesions. PDT caused significant, dose-responsive immunosuppression at high (75 mW cm(-2)) but not low (15 or 45 mW cm(-2)) fluence rates. DNA photolesions, which may be a trigger for immunosuppression, were observed after high-fluence-rate PDT but not when light was delivered more slowly. This study demonstrates that the current clinical PDT protocol (75 mW cm(-2)) is highly immunosuppressive. Simply reducing the rate of irradiation, while maintaining the same light dose, prevented immunosuppression and genetic damage and may have the potential to improve skin cancer outcomes.

Topical photodynamic therapy (PDT) is a widely approved therapy for actinic keratoses, squamous cell carcinoma in-situ, superficial and certain thin basal cell carcinomas. Recurrence rates are typically equivalent to existing therapies, although inferior to surgery for nodular basal cell carcinoma. PDT can be used both as a lesional or as a field therapy and has the potential to delay/reduce the development of new lesions. PDT has also been studied for its place in the treatment of, as well as its potential to prevent, superficial skin cancers in immune-suppressed patients, although sustained clearance rates are lower than for immunocompetent individuals. Many additional indications have been evaluated, including photo-rejuvenation and inflammatory and infective dermatoses. This S2 guideline considers all current and emerging indications for the use of topical photodynamic therapy in Dermatology, prepared by the PDT subgroup of the European Dermatology Forum guidelines committee. It presents consensual expert recommendations reflecting current published evidence. An unabridged version of this guideline is available online at: http://www.euroderm.org/edf/index.php/edf-guidelines.

INTRODUCTION Daylight-mediated photodynamic therapy has been shown to be an effective therapy for actinic keratoses (AKs) and a simple and tolerable treatment procedure in three randomized Scandinavian studies and two recent Phase III randomized controlled studies in Australia and Europe. OBJECTIVES To establish consensus recommendations for the use of daylight photodynamic therapy (DL-PDT) using topical methyl aminolaevulinate (MAL) in European patients with AKs. METHODS The DL-PDT consensus recommendations were developed on behalf of the European Society for Photodynamic Therapy in Dermatology and comprised of 10 dermatologists from different European countries with experience in how to treat AK patients with PDT. Consensus was developed based on literature review and experience of the experts in the treatment of AK using DL-PDT. RESULTS The recommendations arising from this panel of experts provide general guidance on the use of DL-PDT as a dermatological procedure with specific guidance regarding patient selection, therapeutic indications, when to treat, pre-treatment skin preparation, MAL application and daylight exposure for patients with AK in different countries of Europe. CONCLUSIONS This consensus recommendation provides a framework for physicians to perform DL-PDT with MAL cream while ensuring efficiency and safety in the treatment of patients with AK in different European countries.

Summary Background Various effective therapeutic options are currently available for the treatment of actinic keratosis (AK) and basal cell carcinoma (BCC), but none is perfect. Poor cosmesis resulting from surgical procedures and skin irritation induced by topical agents remain significant problems. Objectives To evaluate the cost-effectiveness of a recent approach, methyl aminolaevulinate-based photodynamic therapy (MAL-PDT; Metvix®; Galderma, Lausanne, Switzerland) in AK and BCC. Methods A medical decision tree was developed for simulation of all possible outcomes associated with the medical decision to apply MAL-PDT or a comparator. The time horizon was 1 year for AK and 5 years for BCC. The comparators were cryotherapy in AK and excision surgery in BCC. Clinical data for the model were obtained from the literature. Data on medical management resulted from a Delphi panel performed among 12 Belgian dermatologists. Based on the model, the cost per full responder was calculated, whereby a responder was defined as a patient with all lesions clinically responding and showing an excellent cosmetic result. Results MAL-PDT is a more expensive treatment compared with cryotherapy for AK. However, the cost per full responder is comparable with cryotherapy (€363 and €379, respectively). Incremental cost per extra full responder is €401. Incremental cost per full responder is €469 for nodular BCC and €251 for superficial BCC, both compared with excision surgery. Conclusions The results suggest that MAL-PDT is a cost-effective intervention in AK taking a 1-year time horizon, if society is willing to pay €1·50 per day of response, and that MAL-PDT is better value for money than excision in BCC, taking a 5-year time horizon.

Summary Background Basal cell carcinoma (BCC) may be difficult to treat by conventional means, particularly if the lesions are large or located in the mid-face (H-zone). Photodynamic therapy (PDT) using topical methyl aminolaevulinate (MAL) may be a good noninvasive option for these patients. Objectives To investigate the efficacy and safety of PDT using MAL for BCCs defined as ‘difficult to treat’, i.e. large lesions, in the H-zone, or in patients at high risk of surgical complications. Methods This was a prospective, multicentre, noncomparative study. Patients were assessed 3, 12 and 24 months after the last PDT treatment. One hundred and two patients with ‘difficult-to-treat’ BCC were treated with MAL PDT, using 160 mg g )1 cream and 75 J cm )2 red light (570‐670 nm), after lesion preparation and 3 h of cream exposure. Results Ninety-five patients with 148 lesions were included in the per protocol analysis. The histologically confirmed lesion complete response rate at 3 months was 89% (131 of 148). At 12 months, 10 lesions had reappeared, and therefore the cumulative treatment failure rate was 18% (27 of 148). At 24 months, an additional nine lesions had reappeared, resulting in a cumulative treatment failure rate of 24% (36 of 148). The estimated sustained lesion complete response rate (assessed using a time-to-event approach) was 90% at 3 months, 84% at 12 months and 78% at 24 months. Overall cosmetic outcome was judged as excellent or good in 79% and 84% of the patients at 12 and 24 months, respectively. Follow-up is continuing for up to 5 years. Conclusions MAL PDT is an attractive option for ‘difficult-to-treat’ BCC. Because of the excellent cosmetic results, the treatment is particularly well suited for lesions that would otherwise require extensive surgical procedures.

Summary Background Methyl aminolaevulinate photodynamic therapy (MAL-PDT) is an effective treatment for Bowen disease (BD) of the lower extremities. Er:YAG (erbium:yttrium-aluminium-garnet) ablative fractional laser (AFL) treatment removes the stratum corneum to increase MAL uptake and may improve efficacy. However, no studies have directly compared the efficacy of MAL-PDT with and without Er:YAG AFL therapy in treating BD of the lower extremities in Asians. Objectives To compare the efficacy, recurrence rate, cosmetic outcomes and safety between Er:YAG AFL-assisted MAL-PDT (Er:YAG AFL-PDT) and standard MAL-PDT. Methods Twenty-one patients with a total of 58 BD lesions randomly received either one session of Er:YAG AFL-PDT or two sessions of MAL-PDT in two symmetrical areas. Er:YAG AFL therapy was performed with 550–600 μm ablation depth, level 1 coagulation, 22% treatment density and a single pulse. MAL cream was then applied under occlusion for 3 h and illuminated with a red light-emitting diode lamp at 37 J cm−2. A second session of MAL-PDT was administered 7 days later. Overall response rate, recurrence rate, cosmetic outcomes and safety were assessed at 1 week, 3 and 12 months after treatment. Results After 3 months, Er:YAG AFL-PDT was significantly more effective (93·8%) than MAL-PDT (73·1%; P = 0·031), and the recurrence rate was significantly lower for Er:YAG AFL-PDT (6·7%) than MAL-PDT (31·6%) at 12 months (P = 0·022). No significant difference was found between Er:YAG AFL-PDT and MAL-PDT in terms of cosmetic outcomes or safety. Conclusions Er:YAG AFL-PDT showed significantly higher efficacy and lower recurrence rate than did standard MAL-PDT for treating lower extremity BD in an Asian population.

Background Two phase III trials of photodynamic therapy (PDT) with BF-200 ALA, a recently approved nanoemulsion formulation of 5-aminolaevulinic acid (ALA) demonstrated high clearance rates in mild-to-moderate actinic keratosis (AK). The comparison to a registered methyl aminolaevulinate (MAL) cream demonstrated significantly superior total patient clearance rates. Objectives To evaluate long-term efficacy and safety of PDT for AK 6 and 12 months after the last PDT with BF-200 ALA, MAL or placebo. Methods The follow-up phase (FUP) was performed with patients of two phase III studies. Both studies compared BF-200 ALA with placebo, one of the studies additionally with MAL. Overall recurrence rates and various subgroups (light source, lesion severity, lesion location, complete responders after first PDT) were assessed 6 and 12 months after the last PDT. Results Recurrence rates were similar for BF-200 ALA and MAL, with a tendency to lower recurrence rates for BF-200 ALA. The proportion of patients who were fully cleared during PDT and remained completely clear for at least 12 months after PDT were 47% for BF-200 ALA (both studies) and 36% for MAL treatment. The subgroup that was illuminated with narrow wavelength LED lamps reached 69% and 53% for BF-200 ALA (both studies, respectively) and 41% for MAL. No safety concerns were reported. Conclusions The FUP data confirmed the high efficacy and safety of PDT with BF-200 ALA. The slightly lower recurrence rates after BF-200 ALA treatment compared with MAL treatment enhanced the better treatment outcome due to the significantly superior efficacy.

Basal cell carcinoma (BCC) responds well to topical photodynamic therapy (PDT), with high clearance rates of 72-100%, although the therapy showed limited effectiveness for lesions2 mm thick. Tumor thickness is thought to be associated with therapeutic response.The purpose of this study was to investigate the efficacy, safety, and response depth of methyl aminolaevulinate (MAL) PDT for BCC.After application of MAL emulsion, each lesion was irradiated with 633-nm red light (total dose: 339 J/cm(2)). Complete response (CR) rates were assessed by histological examination at 6, 12, and 24 months.Forty-seven patients (95 lesions) with skin type IV/V were enrolled. Overall CR rate at 24 months was 75.8%. Superficial BCC was more responsive than other subtypes. Tumor thickness beyond subtype was significantly associated with CR rate. Three response depths are proposed: absolute CR (1.3 mm), relative response (1.3 -1.8 mm) and no response (1.8 mm). Although the recurrence rate (24%) is higher than with conventional surgical excision, 90.3% of patients were satisfied with the cosmetic outcome.MAL-PDT offers a noninvasive effective treatment; however, it is not the first option for most BCCs, except inoperable cases. The tumor thickness, independent of subtype, is predictive of PDT response.

Summary Background Although discovered over a century ago it is only in the last 25 years that photodynamic therapy (PDT) has been the focus of intense research. This versatile treatment modality has been shown to be effective in treating a wide variety of malignancies, and with the increasing incidence of non-melanoma skin cancer (NMSC) is a recognised treatment in dermatology clinics worldwide. There is little known as to whether different body sites influence the uptake and conversion of 5-aminolaevulinic acid (ALA) or methyl aminolaevulinate (MAL) to protoporphyrin IX (PpIX). In this study we investigated the characteristics of PpIX fluorescence within normal skin following the application of both ALA and MAL to four different body sites and the effect of tape stripping. Methods A total of 17 healthy volunteers were recruited, and both ALA and MAL were applied to the inner forearm, outer forearm, lower leg and back for 4 h. PpIX fluorescence was detected using a non-invasive spectroscopy system. Results and conclusions PpIX fluorescence (following the application of either ALA or MAL) does vary significantly at different body sites with the lower leg producing the least. Following the application of ALA, peak fluorescence was noted at all body sites at 24 h, except the lower leg, which peaked at 7 h. In contrast MAL induced fluorescence at all body sites, peaked earlier at 7 h and had significantly decreased by 24 h. Removal of the stratum corneum by tape stripping was also shown to significantly increase PpIX fluorescence but did not alter the time course.

Methyl aminolaevulinate photodynamic therapy is increasingly practiced in the treatment of actinic keratoses, Bowen's disease and basal cell carcinomas. This method is particularly suitable for treating multiple lesions, field cancerization and lesions in areas where a good cosmetic outcome is of importance. Good treatment routines will contribute to a favourable result. The Norwegian photodynamic therapy (PDT) group consists of medical specialists with long and extensive PDT experience. With support in the literature, this group presents guidelines for the practical use of topical PDT in non-melanoma skin cancer.

Summary Background. Acne vulgaris is a common skin problem that affects up to 90% of adolescents. Colonization of the duct with Propionibacterium species is one of the factors implicated in the development of acne. Owing to the increasing incidence of antibiotic resistance, there has been an greater interest in the development of new methods to treat acne. Early studies have shown that photodynamic therapy (PDT) with aminolaevulinic acid (ALA) can lead to prolonged improvement in acne. Newer derivatives of ALA such as methyl aminolaevulinate hydrochloride (MAL) and hexyl aminolaevulinate hydrochloride (HAL) have been developed for use in PDT, with the potential benefits of higher lipophilicity and penetration potential. Objectives. To determine the microbiological effect and tolerability of a single application of HAL-PDT and to compare it with MAL-PDT in healthy volunteers. Methods. This was a randomised double-blind study to examine the microbiological effects and safety of a single application of MAL-PDT and HAL-PDT on normal skin in 18 healthy volunteers. Bacterial skin samples for Propionibacterium spp. and Micrococceae were obtained at baseline and 2, 4, 7 and 14 days. Results. Following PDT with MAL and HAL, a statistically significant transient reduction in mean density of Propionibacterium spp. 2 days after treatment using each agent (P

For solar keratoses and superficial basal cell carcinoma, loose crusts and debris are removed with a small curette or blade, and the lesion surface is roughened by gentle scraping. Damage to the surrounding normal skin should be avoided. For nodular BCC, the epidermal keratin layer (which can impede absorption) is removed with a scalpel blade or curette, and the exposed tumour material gently removed. Local anaesthesia is rarely used, but if required it should be used without adrenaline. Methyl aminolaevulinate (MAL) PDT treatment relies on the production of reactive oxygen species; adrenaline will cause vasoconstriction, leading to less tissue oxygenation. If bleeding occurs during lesion preparation, light pressure should be applied. Treatment can be continued once bleeding stops.

Hidradenitis suppurativa (HS) and pilonidal cysts are chronic, inflammatory skin conditions involving apocrine gland-bearing skin. Treatment is limited and unsatisfactory. Photodynamic therapy (PDT) has been reported to be safe and effective in the treatment of several off-label skin conditions. We report the case of a 29-year-old man affected by HS and pilonidal cysts since the age of 21. In the past, the patient was treated with antibiotics, corticosteroids and retinoids, without significant clinical improvement. Treatment with methyl aminolaevulinate (MAL)-PDT was started. A topical MAL cream (Metvix) was applied to the affected areas with an occlusive dressing for 3 h and irradiated with a red light source. Therapy was repeated every 15 days for a total of nine applications. The patient completed a 6-month follow-up and achieved an almost complete clinical remission of the skin lesions (80%) and complete resolution of the itching and discomfort. This is the first case of HS associated with pilonidal cysts treated with MAL-PDT. MAL-PDT was effective and well tolerated in our patient. The costs of this therapy represent an important limitation, taking into account the high number of sessions that were performed compared with non-melanoma skin cancers.