Monochromatic excimer light (308 nm): an immunohistochemical study of cutaneous T cells and apoptosis-related molecules in psoriasis

Pathogenesis, multi-omics research, and clinical treatment of psoriasis

Psoriasis is a common inflammatory skin disease involving interactions between keratinocytes and immune cells that significantly affects the quality of life. It is characterized by hyperproliferation and abnormal differentiation of keratinocytes and excessive infiltration of immune cells in the dermis and epidermis. The immune mechanism underlying this disease has been elucidated in the past few years. Research shows that psoriasis is regulated by the complex interactions among immune cells, such as keratinocytes, dendritic cells, T lymphocytes, neutrophils, macrophages, natural killer cells, mast cells, and other immune cells. An increasing number of signaling pathways have been found to be involved in the pathogenesis of psoriasis, which has prompted the search for new treatment targets. In the past decades, studies on the pathogenesis of psoriasis have focused on the development of targeted and highly effective therapies. In this review, we have discussed the relationship between various types of immune cells and psoriasis and summarized the major signaling pathways involved in the pathogenesis of psoriasis, including the PI3K/AKT/mTOR, JAK-STAT, JNK, and WNT pathways. In addition, we have discussed the results of the latest omics research on psoriasis and the epigenetics of the disease, which provide insights regarding its pathogenesis and therapeutic prospects; we have also summarized its treatment strategies and observations of clinical trials. In this paper, the various aspects of psoriasis are described in detail, and the limitations of the current treatment methods are emphasized. It is necessary to improve and innovate treatment methods from the molecular level of pathogenesis, and further provide new ideas for the treatment and research of psoriasis.

Efficacy of Phototherapy With 308-nm Excimer Light for Skin Microbiome Dysbiosis and Skin Barrier Dysfunction in Canine Atopic Dermatitis

The management of canine atopic dermatitis, an allergic skin disorder, is challenging. To investigate the effect of phototherapy using a 308-nm excimer light as a topical treatment for canine atopic dermatitis, 10 dogs with canine atopic dermatitis and 10 with non-allergic skin were enrolled in this study. Phototherapy was applied every 7 days for a total of 2 months. The skin microbiome, skin barrier function, and clinical outcomes were evaluated after phototherapy. Phototherapy significantly changed the composition of the skin microbiome of dogs with atopic dermatitis and significantly increased the relative abundance of the phyla Actinobacteria and Cyanobacteria. It significantly alleviated the clinical signs of canine atopic dermatitis without serious adverse effects. Transepidermal water loss, as a measure of skin barrier function, significantly decreased after phototherapy. In addition, phototherapy increased microbial diversity and decreased the relative abundance of Staphylococcus pseudintermedius associated with the severity of canine atopic dermatitis. These results suggest that the excimer light therapy is a suitable and safe therapeutic option for canine atopic dermatitis, which is also a spontaneous animal model of atopic dermatitis.

308-nm Excimer Lamp vs. Combination of 308-nm Excimer Lamp and 10% Liquor Carbonis Detergens in Patients With Scalp Psoriasis: A Randomized, Single-Blinded, Controlled Trial

Background: Scalp psoriasis is usually refractory to treatment. Excimer devices have been proved to be a promising therapeutic option in psoriasis. Greater efficacy of phototherapy can be achieved by concurrent use of coal tar derivatives.

Objective: We aimed to compare efficacy and safety between 308-nm excimer lamp monotherapy and a combination of 308-nm excimer lamp and 10% liquor carbonis detergens in the treatment of scalp psoriasis.

Methods: In this randomized, evaluator-blinded, prospective, comparative study, 30 patients with scalp psoriasis received either 308-nm excimer lamp monotherapy or a combination of 308-nm excimer lamp and 10% liquor carbonis detergens twice per week until complete remission of the scalp or for a total of 30 sessions. Efficacy was evaluated by the improvement of Psoriasis Scalp Severity Index (PSSI) score, itch score, and Scalpdex score.

Results: Both treatments induced significant improvement in PSSI score with greater reduction observed in the combination group. At 30th visit, a 75% reduction in PSSI (PSSI75) was attained by 4 (28.6%) and 9 (69.2%) patients treated with monotherapy and combination therapy, respectively (P < 0.05).

Conclusions: Excimer lamp is well-tolerated in patients with scalp psoriasis and liquor carbonis detergens can be used as a combination therapy to improve the efficacy of excimer lamp.

Therapeutic wavelengths of ultraviolet B radiation activate apoptotic, circadian rhythm, redox signalling and key canonical pathways in psoriatic epidermis

Ultraviolet B radiation (UVB) exerts pleiotropic effects on human skin. DNA damage response and repair pathways are activated by UVB; if damage cannot be repaired, apoptosis ensues. Although cumulative UVB exposure predisposes to skin cancer, UVB phototherapy is widely used as an effective treatment for psoriasis. Previous studies defined the therapeutic action spectrum of UVB and showed that psoriasis is resistant to apoptosis. This study aimed to investigate early molecular responses within psoriasis plaques following irradiation with single equi-erythemogenic doses of clinically-effective (311 nm, narrow-band) compared to clinically-ineffective (290 nm) UVB. Forty-eight micro-dissected epidermal samples from 20 psoriatic patients were analyzed using microarrays. Our bioinformatic analysis compared gene expression between 311 nm irradiated, 290 nm irradiated and control psoriasis epidermis to specifically identify 311 nm UVB differentially expressed genes (DEGs) and their upstream regulatory pathways. Key DEGs and pathways were validated by immunohistochemical analysis. There was a dynamic induction and repression of 311 nm UVB DEGs between 6 h and 18 h, only a limited number of DEGs maintained their designated expression status between time-points. Key disease and function pathways included apoptosis, cell death, cell migration and leucocyte chemotaxis. DNA damage response pathways, NRF2-mediated oxidative stress response and P53 signalling were key nodes, interconnecting apoptosis and cell cycle arrest. Interferon signalling, dendritic cell maturation, granulocyte adhesion and atherosclerotic pathways were also differentially regulated. Consistent with these findings, top transcriptional regulators of 311 nm UVB DEGs related to: a) apoptosis, DNA damage response and cell cycle control; b) innate/acquired immune regulation and inflammation; c) hypoxia/redox response and angiogenesis; d) circadian rhythmicity; f) EGR/AP1 signalling and keratinocyte differentiation; and g) mitochondrial biogenesis. This research provides important insights into the molecular targets of 311 nm UVB, underscoring key roles for apoptosis and cell death. These and the other key pathways delineated may be central to the therapeutic effects of 311 nm in psoriasis.

Beneficial Effects of Near-Infrared Light Photobiomodulation in Linear Morphea: A Case Report

Background: Linear morphea is a variant of scleroderma limited to the skin and underlying tissues secondary to an autoimmune inflammation leading to excess collagen deposition and fibrosis. Apart from topical or oral medications, successful light-based treatments have been reported using phototherapy including Psoralen plus ultraviolet A, photodynamic therapy, carbon dioxide laser, pulsed dye laser, and visible/infrared light. Methods: We report a patient with biopsy-proven infraorbital linear morphea responding to 940 nm near-infrared light photobiomodulation treatments. Results: The patient had excellent cosmesis without textural changes or hypopigmentation despite her darker skin complexion (Fitzpatrick phototype III) after tri-weekly treatments for 8 months. Conclusions: Linear morphea, therefore, may be potentially amenable to home use light-based therapy by using nonthermal nonablative 940 nm photons. To our knowledge, this home-based treatment approach has not been previously reported.

Excimer laser/light treatment of alopecia areata: A systematic review and meta-analyses

BACKGROUND

The excimer laser/light (EL) has been reported to be effective for alopecia areata (AA), but its treatment response has not been systematically reviewed.

OBJECTIVE

To determine the treatment response and safety of EL treatment of AA.

METHODS

A comprehensive search of the Medline, EMBASE, Cochrane library, and Web of Science (from inception to December 31, 2018) was conducted to identify prospective clinical studies assessing the treatment response of EL for AA. The primary outcome was cosmetically acceptable hair regrowth (hair regrowth ≥75%); random-effects meta-analyses using generic inverse variance weighting were performed to estimate treatment responses. The study was registered with PROSPERO (CRD42019121092).

RESULTS

Of 52 records initially identified, 13 full-text articles were finally assessed in terms of eligibility. A total of 9 prospective clinical studies (129 AA patients) including 5 controlled clinical trials were identified. Cosmetically acceptable hair regrowth was achieved in 50.2% (95% confidence interval 31.5%-68.9%; 8 studies). EL treatment significantly improved hair regrowth compared with untreated controls (relative risk 7.83; 95% confidence interval 2.11-29.11; 5 controlled clinical trials). No serious adverse effect was noted.

CONCLUSIONS

EL treatment appeared to produce a favorable therapeutic response in AA patients. The use of EL should be encouraged for AA patients with the advantages of the non-invasiveness and no systemic effect.

The effects of UVB irradiance on vitiligo phototherapy and UVB-induced photocarcinogenesis

Phototherapy is the most commonly used modality for repigmenting vitiligo. Currently, UVB emitting devices, including narrow-band UVB (NBUVB) and excimer laser/light, are considered as the treatment of choice. While emitting wavelengths at close proximity, excimer lights emit higher irradiance (HI; W/m² ) compared to NBUVB. Clinical reports have shown that excimer light is more efficacious in treating vitiligo compared to NBUVB, and we demonstrated that irradiance plays a critical role in promoting melanoblasts differentiation. UVB radiation from the sun is closely associated with photocarcinogenesis of the skin. Sunscreens were used to protect the skin by reducing UVB irradiance (low irradiance (LI) UVB). Sunscreen use was associated with skin cancer reduction in clinical trials. Paradoxically, sunscreen use was associated with increased sunburn episodes in the real-world settings. It was shown that UVB-induced sunburn depends on fluence (J/m² ) but not irradiance of UVB radiation. We investigated the significance of irradiance in the context of UVB-induced carcinogenesis of the skin. For mice receiving equivalent fluence of UVB exposure, the LIUVB-treated mice showed earlier tumor development, larger tumor burden, and more epidermal keratinocytes harboring mutant p53 as compared to their HIUVB-treated counterparts. These results suggested that at equivalent fluence, LIUVB radiation has more photocarcinogenic potential on the skin compared to its HI counterpart. Since development of sunburn with or without sunscreen use indicates that certain threshold of UVB fluence has been received by the skin at LI and HI, respectively, sunburn episodes with sunscreen use (LIUVB) are more damaging to the skin compared to that without sunscreen (HIUVB) application. In summary, since irradiance plays an important role determining the biological effects of UVB radiation on the skin, future related studies should take this critical parameter into consideration.

Beyond the Booth: Excimer Laser for Cutaneous Conditions

The excimer laser has emerged as an efficacious treatment modality for many dermatologic diseases. The excimer laser is an alternative to standard narrowband ultraviolet B (NBUVB) phototherapy treatment in patients with limited disease. In comparison to standard NBUVB, the excimer laser requires fewer treatment sessions, has reduced treatment duration, requires a lower cumulative UVB dose, and limits UVB exposure to lesional skin. This review addresses the mechanism, safety, application, and efficacy of the excimer laser for the treatment of these conditions.

Frontal Fibrosing Alopecia: An Update on Pathogenesis, Diagnosis, and Treatment

Frontal fibrosing alopecia (FFA), first described by Kossard in the early 1990s, is a form of primary lymphocytic cicatricial alopecia characterized by selective involvement of the frontotemporal hairline and eyebrows. Since the original description, an increasing number of cases have been reported worldwide and the clinical aspects of the disease have been better characterized. However, the pathogenesis is still unknown and several hypotheses have been made about possible triggering factors, including hormones, neurogenic inflammation, smoking, UV filters, and ingredients in leave-on facial products. A genetic basis has also been hypothesized as the disease can occur in siblings and members of the same family. Besides its pathogenesis, research is also focused on treatment; FFA is a chronic condition and at present there is no validated or approved treatment for this disorder. Commonly prescribed topical treatments include corticosteroids, minoxidil, and calcineurin inhibitors. Systemic treatments include 5α-reductase inhibitors, hydroxychloroquine, and retinoids. Intralesional triamcinolone acetonide is also utilized, especially for the eyebrows. Other possible treatments include pioglitazone, naltrexone, tofacitinib, and lasers.

Efficacy and safety of 308-nm excimer lamp in the treatment of scalp psoriasis: a retrospective study

BACKGROUND

Scalp psoriasis is a major therapeutic challenge due to the hindrance caused by hair. Treatment with the 308-nm excimer lamp is purported to provide many benefits over conventional phototherapy. This retrospective study evaluates the efficacy, safety, and effective dosage of 308-nm excimer light in the treatment of scalp psoriasis.

METHODS

We retrospectively reviewed the medical records of patients with scalp psoriasis who received treatment with 308-nm excimer light. Clinical and epidemiological data as well as details regarding treatment were statistically analyzed to determine the treatment outcomes.

RESULTS

Twenty patients with scalp psoriasis were included in the study. Their mean age was 47.45 ± 17.93 years. Eleven patients responded to treatment at the end of 10 sessions. The median baseline Psoriatic Scalp Severity Index (PSSI) was 12 (range, 3-32). At the end of the protocol, the median PSSI was 4.5 (range, 0-24), indicating a statistically significant reduction (P < 0.001). Common adverse effects included erythema, irritation, and desquamation.

CONCLUSION

The 308-nm excimer light appears to be an effective and safe modality that requires short treatment time. The modality could be considered as an alternative or adjuvant treatment for scalp psoriasis.

[The 308 nm Excimer laser for the treatment of psoriasis and inflammatory skin diseases]

Overall, the 308 nm Excimer laser enables not only a more effective and safer UVB therapy than classical UV phototherapy, but also targeted irradiation in higher doses with a lower cumulative load, which results in faster healing of mainly circumscribed skin changes. This also applies to therapy-resistant residual lesions which, despite systemic therapy, did not diminish. Combination therapies usually improve the result and enable the dose of UVB and systemic medication to be reduced. Excimer laser therapy can be used for an increasing number of skin diseases, especially those that respond to phototherapy or photochemotherapy.

Novel therapies for alopecia areata: The era of rational drug development

Treatments for alopecia areata (AA) have evolved over the decades from broad and nonspecific therapies to those that are now more targeted and rationally selected. This was achieved by means of close cooperation and communication between clinicians and basic scientists, which resulted in the elucidation and understanding of the unique pathophysiology of AA. In this review we discuss this evolution and how novel therapies for AA have changed over the decades, what we have in our current arsenal of drugs for this potentially devastating disease, and what the future holds.

Therapy of Oral Lichen Planus with Monochromatic Excimer Light

Oral lichen planus can cause considerable inconvenience to the patient and is often resistant to the various therapeutic options used, tending to become chronic. The monochromatic excimer light 308 nm is UVB radiation generated and has already been used with good results in the treatment of psoriasis, vitiligo and, less frequently, lichen cutaneous. The purpose of this study is to assess the clinical efficacy of monochromatic excimer light in the treatment of symptomatic oral lichen planus. Twenty patients were treated weekly with single phototherapic sessions. The therapy was suspended on achieving a total score of gravity at least 35% or less than the score of departure. At the end of the study scoring on the size of lesions, intensity of white, intensity of erythema, grade of sick oral gingiva, for both gingival and non-gingival lichen was improved. The statistical processing found a highly significant reduction in post-therapy (p< 0002) of all subjective manifestations tested. Side effects were not observed. Our study shows that monochromatic excimer light 308 nm would appear to be an effective and well-tolerated treatment for oral lichen planus and could represent a new additional therapeutic strategy.

Phototherapy and Combination Therapies for Vitiligo

Vitiligo is a disease characterized by disappearance of melanocytes from the skin. It can negatively influence the physical appearance of affected individuals, and may profoundly affect a person's psychosocial function and quality of life. Therefore, vitiligo should not be considered as merely a condition that affects a patient's appearance, but needs to be actively treated in patients who seek medical help. Phototherapy has been used as the main treatment modality for patients with vitiligo. Different forms of phototherapy for vitiligo include broadband UVB, narrowband UVB, excimer light and excimer laser, and psoralen plus UVA.

Pustular Palmoplantar Psoriasis Successfully Treated with Nb-UVB Monochromatic Excimer Light: A Case-Report

Barber’s palmoplantar pustulosis (PPP) is a form of localised pustular psoriasis, affecting the palmar and plantar surfaces. It is a chronic disease, with a deep impact on the patients’ quality of life. The Authors discuss a case of Baber Psoriasis successfully treated with monochromatic excimer light.

A comparative study for the short-term effects of targeted high-intensity UVB and narrow-band UVB in the treatment of vitiligo

Vitiligo is a common acquired depigmentation disorder for which many treatments have previously been used with varying effects. The aim of the present study was to evaluate the efficacy and safety of targeted high-intensity (TH) and narrow band (NB) ultraviolet B light (UVB) for vitiligo treatment. A total of 33 patients with vitiligo were enrolled in the present study. Patients with a symmetrical or near-symmetrical distribution of lesions on their bodies were selected for the present study. For each patient, half of the body was treated with TH-UVB and the other with NB-UVB twice weekly over a period of 12 weeks (24 times total). The patients were assessed each week for repigmentation of lesions. All data were analyzed using SPSS software, and a total of 30 patients were evaluated. The effective rate was significantly higher in the TH-UVB group (56.7%) compared with the NB-UVB group (20.0%; P<0.05). Additionally, the mean number of radiations necessary for initial repigmentation was significantly lower in the TH-UVB group (7.95±3.43) compared with the NB-UVB group (15.36±3.43; P<0.05). No correlation was found between the clinical features of patients and the efficacy of treatment. In summary, the results of the present study suggest that TH-UVB is a more effective treatment for vitiligo than NB-UVB.

Does imiquimod pretreatment optimize 308-nm excimer laser (UVB) therapy in psoriasis patients?

BACKGROUND/PURPOSE

Psoriasis continues to be a debilitating skin disease affecting 1-3% of the United States population. Although the effectiveness of several current biologic therapies have described this pathology as a IL-23, TNF-a and Th17-mediated disease, less invasive approaches are still in use and in need of refinement. One of these is the usage of narrow band-UVB (NB-UVB) therapy to deplete specifically intra-epidermal CD3+, CD4+ and CD8+ cells to clear psoriatic plaques.

AIMS/OBJECTIVES

In order to improve NB-UVB therapy, we sought to determine whether skin pre-treatment with the TLR7 agonist imiquimod (IMQ) would help increase the efficiency of the former at resolving psoriatic plaques.

MATERIALS AND METHODS

Eucerin^® Original Moisturizing Lotion (topical vehicle) or Aldara^® (imiquimod 5% topical cream) were applied for 5 days once daily to a maximum contiguous area of 25 cm² (5 cm × 5 cm area). Patients were provided with sachets containing 12.5 mg of imiquimod each and were instructed to apply imiquimod (I) to two psoriasis plaques (5 sachets of imiquimod allotted to each plaque). A PHAROS excimer Laser EX-308 (Ra Medical Systems, Inc. Carlsbad, CA, USA) with an output of monochromatic 308-nm light and pulse width of 20-50 ns was used for all patients. Punch biopsies of psoriatic lesions (6 mm) were taken at 4 and 48 h after final application of topical treatment with or without excimer laser treatment. Real-time quantitative RT-PCR was performed according to manufacturer's instructions and Inmunohistochemistry was used as described before.

RESULTS

Our results suggests that although IMQ seemed to activate the type I interferon pathway as previously described, its concomitant usage with NB-UVB for clearing psoriatic skin was ineffective. Although upregulation of genes MxA, GRAMD1A and DMXL2 suggested that IMQ treatment did induce skin changes in psoriasis patients, more optimal dosing of IMQ and NB-UVB might be necessary to achieve desired treatment responses.

CONCLUSION

The observation that psoriasis involvement was not aggravated by usage of topical IMQ was encouraging. Additional observational studies might be necessary to further tailor the combination of IMQ with NB-UVB therapy to reliably improve the psoriatic pathology.

Effect of a 308-nm excimer laser on atopic dermatitis-like skin lesions in NC/Nga mice

BACKGROUND AND OBJECTIVE

Atopic dermatitis (AD) is a common inflammatory skin disease that can affect all age groups. It has a relapsing course, which dramatically affects the quality of life of patients. A 308-nm excimer laser has been reported to be a safe and effective treatment for inflammatory skin diseases, although the range of potential application has not been fully explored. The purpose of this study was to evaluate the therapeutic effects of a 308-nm laser on AD-like skin lesions in NC/Nga mice.

STUDY DESIGN/MATERIALS AND METHODS

Dermatophagoides farinae-exposed NC/Nga mice with a clinical score of 12 were treated with either a 308-nm excimer laser or narrowband-UVB (NB-UVB). The effects of the 308-nm excimer laser were evaluated by dermatitis scores, skin histology, skin barrier function, and immunological parameters, including IgE and Th2-mediated cytokines.

RESULTS

The 308-nm excimer laser significantly reduced the severity of skin lesions and decreased the total serum levels of IgE and Th2-mediated cytokines. The excimer laser also significantly reduced the inflammatory cellular infiltrate into AD-induced skin lesions. Moreover, treatment with the 308-nm excimer laser led to recovery of skin barrier function in AD-induced skin lesions.

CONCLUSION

The 308-nm excimer laser can be considered a valid and safe therapeutic option for the treatment of localized AD. Lasers Surg. Med. 48:629-637, 2016. © 2016 Wiley Periodicals, Inc.

Excimer laser therapy and narrowband ultraviolet B therapy for exfoliative cheilitis

BACKGROUND

Exfoliative cheilitis is a condition of unknown etiology characterized by hyperkeratosis and scaling of vermilion epithelium with cyclic desquamation. It remains largely refractory to treatment, including corticosteroid therapy, antibiotics, antifungals, and immunosuppressants.

OBJECTIVE

We sought to evaluate the safety and efficacy of excimer laser therapy and narrowband ultraviolet B therapy in female patients with refractory exfoliative cheilitis.

METHODS

We reviewed the medical records of two female patients who had been treated unsuccessfully for exfoliative cheilitis. We implemented excimer laser therapy, followed by hand-held narrowband UVB treatments for maintenance therapy, and followed them for clinical improvement and adverse effects.

RESULTS

Both patients experienced significant clinical improvement with minimal adverse effects with excimer laser therapy 600-700 mJ/cm² twice weekly for several months. The most common adverse effects were bleeding and burning, which occurred at higher doses. The hand-held narrowband UVB unit was also an effective maintenance tool.

LIMITATIONS

Limitations include small sample size and lack of standardization of starting dose and dose increments.

CONCLUSION

Excimer laser therapy is a well-tolerated and effective treatment for refractory exfoliative cheilitis with twice weekly laser treatments of up to 700 mJ/cm². Transitioning to the hand-held narrowband UVB device was also an effective maintenance strategy.

Excimer UV radiation in dermatology

Ultraviolet B (UVB 290-320 nm) radiation has been used in the treatment of different skin diseases. Light sources with narrowband UVB output spectrum have been developed with the aim of increasing the rates of “beneficial to side effect” profile of the treatment. Narrowband UVB phototherapy using fluorescent lamps (TL01, 311&#x2213;2nm) has been widely adopted over the past 10 years. Monochromatic Excimer Light (MEL) represents a new source of narrow-band UVB emitting at 308 nm and guarantees a safe and effective approach to different chronic and recurrent skin diseases thanks to its potent and selective immunosuppressant action.

Comparison of the 308-nm excimer laser with the 308-nm excimer lamp in the treatment of vitiligo--a randomized bilateral comparison study

BACKGROUND

Vitiligo is an acquired pigment disorder characterized by areas of depigmented skin resulting from the loss of epidermal melanocytes. Recently, several investigations have documented the benefits of excimer phototherapy (e.g., using the 308-nm excimer laser or the 308-nm excimer lamp) for the treatment of vitiligo.

AIM

To compare the effectiveness of the 308-nm excimer laser with the 308-nm excimer lamp in the treatment of vitiligo patients.

METHODS

This intervention study was designed as a randomized self-control trial. Fourteen subjects with 48 symmetrical vitiligo lesions were enrolled in this study. One lesion was treated with the 308-nm excimer laser, and its counterpart was treated with the 308-nm excimer lamp. Lesions were treated three times a week with the same dose on both sides for a total of 20 sessions.

RESULTS

All of the patients completed the study, and 48 lesions were treated. The two treatments exhibited similar results in terms of repigmentation.

CONCLUSIONS

The 308-nm excimer lamp and the 308-nm excimer laser exhibited similar efficacies in treating vitiligo.

WITHDRAWN: Comparision between 308-nm excimer laser and 308-nm excimer lamp in the treatment of vitiligo - a randomized self control study

Ahead of Print article withdrawn by publisher.

Spectral effects of UV on psoriasis

Ultraviolet B (UVB) is a highly effective, relatively safe, affordable and widely used therapeutic option for moderate psoriasis.

Ultraviolet B (UVB) is a highly effective, relatively safe, affordable and widely used therapeutic option for moderate psoriasis. Several types of UVB lamp are available to treat psoriasis, both broadband and narrowband, allowing a choice of spectral emission. However despite years of clinical use, the mechanism of action of UVB in clearing psoriasis remained incompletely understood. Moreover, there has been little insight into how the relative effectiveness of different UVB wavelengths linked to the mechanism of action, although it is known that the action spectrum for clearance of psoriasis differs from the action spectrum of erythema. This paper examines the existing literature from which our current treatments have evolved, and offers new insight into the use of keratinocyte apoptosis as a biomarker which may help to optimise UV treatment in the future. When combined with a systems biology approach, this potential biomarker may provide insight into which wavelengths of UV are the most effective in clearing psoriasis, allowing a more rational and potentially an individually tailored approach to optimising phototherapy for psoriasis.

Successful treatment with 308-nm monochromatic excimer light and subsequent tacrolimus 0.03% ointment in refractory plasma cell cheilitis

Plasma cell cheilitis is a chronic inflammatory disease that presents with erythema, erosions, ulcers and occasional nodules within the mucosa, including the lips. It is histopathologically characterized by dense plasma cell infiltration in the lamina propria of the mucous membranes. Several treatments for plasma cell cheilitis have been reported, including topical steroids, topical antibiotics or topical tacrolimus. However, 308-nm monochromatic excimer light (MEL) has never been reported as a treatment option, while it was reported to be very effective in treating erosive oral lichen planus. We report a 62-year-old man who had chronic plasma cell cheilitis on the lower lip, which was refractory to topical and systemic corticosteroid. The lesion and severe pain were significantly improved by the treatment with nine sessions of 308-nm MEL twice per week with a total dose of 1120 mJ/cm(2). However, the lesion gradually worsened after treatment frequency was reduced to once per month. Subsequent tacrolimus 0.03% ointment cleared the lesion completely in a month and no recurrence was observed a year later. Refractory plasma cell cheilitis and concomitant severe pain quickly responded to 308-nm MEL when administrated twice per week. Because the long interval between each MEL treatment seemed ineffective to improve the lesion, appropriate frequency and adequate total dose of MEL treatment may be necessary for a successful treatment.

Cytotoxic and genotoxic effects of acitretin, alone or in combination with psoralen-ultraviolet A or narrow-band ultraviolet B-therapy in psoriatic patients

Acitretin is currently used alone or combined with PUVA (psoralen + UVA) or with narrow-band ultraviolet B (NBUVB), to treat moderate and severe psoriasis. However, little is known about the potential genotoxic/carcinogenic risk and the cytostatic/cytotoxic effects of these treatments. Our aim was to study the cytotoxic and genotoxic effects of acitretin - alone or in combination with PUVA or NBUVB - by performing studies with blood from patients with psoriasis vulgaris who were treated with acitretin, acitretin+PUVA or acitretin+NBUVB for 12 weeks, and in vitro studies with blood from healthy volunteers, which was incubated with acitretin at different concentrations. The cytotoxic and genotoxic effects were evaluated by the cytokinesis-blocked micronucleus test and the comet assay. Our results show that psoriatic patients treated with acitretin alone or with acitretin+NBUVB, did not show genotoxic effects. In addition, these therapies reduced the rate of proliferation and induced apoptosis and necrosis of lymphocytes; the same occurred with lymphocyte cultures incubated with acitretin (1.2-20μM). The acitretin+PUVA reduced also the proliferation rate, and increased the necrotic lymphocytes. Our studies suggest that therapy with acitretin alone or combined with NBUVB, as used in psoriatic patients, does not show genotoxic effects, reduces the rate of proliferation and induces apoptosis and necrosis of lymphocytes. The combination of acitretin with PUVA also reduces the proliferation rate and increases the number of necrotic lymphocytes. However, as it induced slight genotoxic effects, further studies are needed to clarify its genotoxic potential.

Guidelines for the management of vitiligo: the European Dermatology Forum consensus

The aetiopathogenic mechanisms of vitiligo are still poorly understood, and this has held back progress in diagnosis and treatment. Up until now, treatment guidelines have existed at national levels, but no common European viewpoint has emerged. This guideline for the treatment of segmental and nonsegmental vitiligo has been developed by the members of the Vitiligo European Task Force and other colleagues. It summarizes evidence-based and expert-based recommendations (S1 level).

UV-based therapy and vitamin D

The ultraviolet (UV) light spectrum has long been known to induce biologic effect on the skin. For a large number of cutaneous disorders, phototherapy and photochemotherapy are effective therapeutic options with excellent safety profiles and well-documented side effects. Despite their ease of administration and benefits, phototherapeutic treatment modalities require appropriate space for the equipment, trained staff, and patient education prior to initiating treatment. However, when the initial barriers to treatment can be overcome, UV therapy can offer patients significant relief from their cutaneous disease. Furthermore, UVB-based phototherapy can produce significant alteration to vitamin D levels. With the recent research implicating association of low vitamin D levels with a variety of health conditions, whether patients receiving phototherapy or, more specifically, those getting vitamin D supplement may be protected from these diseases remains to be established.

Efficacy of monochromatic excimer light (308 nm) in the treatment of atopic dermatitis in adults and children

OBJECTIVE

To demonstrate the efficacy of light produced by a 308 nm xenon-chloride monochromatic excimer light (MEL) in the treatment of localized lesions of atopic dermatitis (AD) in adults and in children.

BACKGROUND DATA

The 308-nm excimer light has been reported to be safe and effective in the treatment of chronic skin diseases, although the range of potential applications has not been fully explored.

METHODS

Twelve adults and six children affected by localized lesions of AD were enrolled in this pilot study and treated with a weekly session of MEL. A range of 6-12 sessions was performed with an increasing dosage according to the patient's phototype and response. Follow-up was for 16 wk.

RESULTS

All patients completed the protocol. At the end of treatment complete remission was observed in 12/18 patients (66.7%), a partial remission in 3/18 (16.7%) and no remission in 3/18 (16.7%). A mean total dose of 21.89 minimal erythemal dose (MED) was performed. Forty-four percent of patients maintained the results achieved at a 16-week follow-up. Treatment was well tolerated overall.

CONCLUSIONS

MEL can be considered as a valid and safe therapeutic option for the treatment of localized AD in adults and children.

Comparison between 308-nm monochromatic excimer light and narrowband UVB phototherapy (311-313 nm) in the treatment of vitiligo--a multicentre controlled study

BACKGROUND

Vitiligo is an acquired pigmentary disorder characterized by areas of depigmented skin resulting from loss of epidermal melanocytes. Recently, it has been shown that narrowband ultraviolet B (NB-UVB) phototherapy may be more effective than psoralen and ultraviolet A (PUVA) photochemotherapy in treating vitiligo, and that 308-nm monochromatic excimer light (MEL) may present some advantages as compared to NB-UVB for the treatment of vitiligo. AIM The aim of this study was to compare the effectiveness of NB-UVB phototherapy and 308-nm MEL in vitiligo patients.

METHODS

The study was done in a randomized, investigator-blinded and half-side comparison design. Twenty-one subjects with symmetrical vitiligo lesions were enrolled in this study. Vitiligo lesions on one body side were treated twice weekly for 6 months with 308-nm MEL, while NB-UVB phototherapy was used to treat lesions on the opposite side.

RESULTS

At the end of the study six lesions (37.5%) treated with 308-nm MEL and only one lesion (6%) treated with NB-UVB achieved an excellent repigmentation (score 4) while four lesions (25%) treated with 308-nm MEL and five lesions (31%) treated with NB-UVB showed a good repigmentation (score 3).

CONCLUSIONS

It appears that 308-nm MEL is more effective than NB-UVB in treating vitiligo lesions and it induces repigmentation more rapidly.

Expression of p53 in lesions and unaffected skin of patients with plaque-type and guttate psoriasis: A quantitative comparative study

Psoriasis is a common inflammatory and hyperproliferative skin disease characterized by hyperproliferation of keratinocytes. The pathogenesis of psoriasis has yet to be determined. The control of cell growth is a delicately balanced process, regulated by external signals or the internal genetic program of an individual cell. In psoriasis, these processes are disturbed and some candidate genes like p53 are suspected of being involved in the pathogenesis of the disease. The p53 protein is essential for the regulation of cell proliferation. The study was performed on 32 patients with psoriasis (24 plaque type, eight guttate type). Biopsy specimens for immunohistochemical determination of p53 protein expression were collected from both the lesional and the nonlesional skin sites that were not exposed to sun in all of the patients (n = 32). Taking the ultraviolet (UV) exposure of the skin into consideration, a third skin sample was taken from each patient (n = 7) who had lesions on the sun-exposed areas. Immunohistochemical assessment of p53 expression in skin was determined as p53 protein expression per 1000 cells (keratinocytes). The statistical analysis revealed that the expressions of p53 per 1000 cells were higher in non-sun-exposed lesional skin than the non-sun-exposed nonlesional skin, also in plaque-type psoriasis than guttate-type psoriasis (P = 0.000, P = 0.046, P = 0.037, respectively). There was a positive correlation between the p53 expression in non-sun-exposed lesional skin versus expression in sun-exposed lesional skin (cubic centimeters = 0.811, P = 0.027). Our results show a stronger association of elevated p53 expression with chronic rather than acute inflammatory psoriasis. This may indicate a mechanistic difference between plaque-type and guttate psoriasis. Alternatively, this could reflect a chronological course as the disease transitions from an acute to a chronic phase.

Comparison of broadband UVB, narrowband UVB, broadband UVA and UVA1 on activation of apoptotic pathways in human peripheral blood mononuclear cells

BACKGROUND/PURPOSE

Ultraviolet (UV) radiation is an important therapy for immune-mediated cutaneous diseases. Activation of early apoptotic pathways may play a role in the clinical effectiveness. Different UV wavelengths have different efficacy for various diseases, but it remains unclear whether the ability to induce apoptosis differs with respect to the wavelength, and whether they induce apoptosis through the same mechanism. The aim of this study is to analyze the effects of different UV wavelengths that are used clinically on normal human peripheral blood mononuclear cells (PBMCs).

METHODS

PBMCs were treated with UV-light sources broadband UVB, narrowband UVB, broadband UVA and UVA1. Initiation of apoptosis was assessed by flow cytometry by staining-treated cells for activated caspases. Immunoblots were performed to measure for cleaved caspase-3, -8, -9, cytochrome c, Bcl 2-interacting domain and poly-(ADP ribose) polymerase cleavage.

RESULTS

We demonstrate that all the UV radiation sources induced caspase activation in a dose-and time-dependent manner. Components of both the extrinsic and intrinsic pathways of apoptosis were activated by all of the UV wavelengths tested, but differed in the level of energy needed for activation.

CONCLUSION

The greater effectiveness of UVB on initiation of apoptotic pathway suggests that apoptosis may play a role in the clinical efficacy of UVB-responsive inflammatory cutaneous diseases.