Excimer light effect on neurogenic inflammation in active versus stable psoriasis lesions.

Neurogenic inflammation, mediated by T helper 17 cell (Th17) and neurons that release neuropeptides such as substance P (SP), is thought to play a role in the pathogenesis of psoriasis. Excimer light is used in the treatment of psoriasis via induction of T cell apoptosis. The objective of this study is to study the effect of excimer light on active versus stable psoriasis and investigate the levels of substance P and its receptor in both groups. The study included 27 stable and 27 active psoriatic patients as well as 10 matched healthy controls. Clinical examination (in the form of local psoriasis severity index (PSI) and visual analogue scale (VAS)) was done to determine disease severity, level of itching, and quality of life. Tissue levels of SP and neurokinin-1 receptor (NK-1R) were measured by ELISA before and after 9 excimer light sessions in 43 patients. A statistically significant lower levels of PSI and VAS were reached after therapy with no significant difference between the stable and active groups. The mean tissue levels of SP before therapy were significantly higher than the control group. Lower levels of SP and NK-1 receptor were found after treatment overall and in each group. Excimer therapy can be effective for both stable and active plaque psoriasis and this effect could be partly through its role on ameliorating the neurogenic inflammation.

A predictive model of the requisite minimal erythema dose between 308-nm monochromatic excimer light and 311-nm narrowband Ultraviolet-B light.

BACKGROUND: There are limited data in the relationship between the minimal erythema dose (MED) of 308-nm monochromatic excimer light (MEL) and 311-nm Narrowband UVB (NB-UVB). OBJECTIVE: To establish a predictive model of the relationship between MEDs of both wavelengths. METHODS: An MED test was performed on the back of 40 healthy Thai volunteers. One side was irradiated with 308-nm MEL, and the opposite side was irradiated with 311-nm NB-UVB. The correlation and a predictive model of the relationships were then analyzed. RESULTS: There was a positive correlation in the MED of both wavelengths (r = 0.82, p < 0.001). A predicted MED of 308-nm MEL was based on Y = 62.421 + 0.439X, where Y and X were a predicted MED of 308-nm MEL and an actual 311-nm NB-UVB, respectively. This model could predict an MED of 308-nm MEL by using an actual MED of 311-nm NB-UVB with a root mean square difference of 13.64%, and a mean bias difference of 0.63%. LIMITATION: All volunteers were Fitzpatrick's skin phototype type IV. The predictive model might not generalize to other skin phototypes. CONCLUSION: We established a predictive model of the relationship between MED of 308-nm MEL and 311-nm NB-UVB with acceptable accuracy.

Erythematous reactions to two ultraviolet excimer therapy devices with different irradiance levels: Reconsidering the reciprocity law.

BACKGROUND: Few studies have examined the effectiveness of the reciprocity law in ultraviolet excimer therapy. This study aimed to examine the difference in erythematous reaction in human skin when the irradiance of ultraviolet excimer treatment devices differed while the irradiation dose was constant. MATERIALS AND METHODS: This study, conducted at the Department of Dermatology, Chiba University, included 15 healthy adults aged 20-65 years (mean age, 46.3 years; seven men). Using ultraviolet excimer treatment devices with different irradiances (50 or 150 mW/cm2 ), the upper abdomen of each participant was irradiated with ultraviolet light at set irradiation doses (80, 100, 120, 140, 160, 180, and 200 mJ/cm2 ). The erythema index of each irradiated site was measured using a melanin- and erythema-measuring device, and the difference in erythema index before and 24 h after irradiation was the primary endpoint. RESULTS: The change in erythema index was significantly higher for an irradiance of 150 mW/cm2 . Significant differences (p < 0.05) were observed between these irradiance levels at irradiation doses of 100-200 mJ/cm2 . CONCLUSIONS: Even for the same irradiation dose, stronger erythematous reactions occurred at higher irradiances in ultraviolet excimer treatment. This suggests that the reciprocity law may not always hold true in excimer therapy.

Efficacy of the combined excimer light and topical calcipotriol for acral vitiligo: A randomized double-blind comparative study.

Excimer light, topical vitamin D analogues, and topical steroids have been reported to be effective treatments for vitiligo. However, monotherapy often demonstrates unfavorable results for acral vitiligo. This study aimed to evaluate the efficacy and safety of combination treatment with 308-nm excimer light and topical calcipotriol or topical clobetasol ointment for acral vitiligo. A prospective, randomized, double-blind, and intraindividual study was conducted. Combination treatment (excimer light and topical medication) was applied in the first 12 weeks, and monotherapy (topical medication alone) was used in the later 12 weeks. Both hands were irradiated with excimer light three times a week for 12 weeks. Calcipotriol ointment was randomly assigned to one hand, whereas clobetasol ointment was assigned to the other hand. The ointments were applied twice daily for a total of 24 weeks. Repigmentation, clinical improvement, and adverse reactions were assessed. A total of 26 hands completed the study. Of the hands treated with excimer light and calcipotriol, approximately 8% achieved excellent repigmentation at the end of the combination treatment period and 23% achieved good to excellent improvement after 12 weeks of calcipotriol monotherapy. More than 85% and 77% of the hands treated with calcipotriol-based and clobetasol-based regimens showed some repigmentation at the end of the study, respectively (P < .05). Nevertheless, no significant difference was found between the treatments. No serious adverse reactions were observed. In conclusion, the combination of excimer light and topical calcipotriol followed by topical calcipotriol alone is effective and might be a promising treatment regimen for acral vitiligo.

Is targeted UVB as effective as excimer light phototherapy in treatment of vitiligo?

Excimer light (EL) and targeted UVB (TUVB) devices have been used successfully in repigmenting vitiligo. To compare the repigmenting efficacy and safety of EL with TUVB device in vitiligo. The study was conducted retrospectively on patients of vitiligo who had received either EL (Group A) or TUVB (Group B) from year 2015 to 2020. Data pertaining to 40 such age and sex matched patients from each group was retrieved with almost similar sites of involvement. Only patients whose phototherapy sessions had been given twice weekly for minimum of 30 sessions or until 90%-100% repigmentation were included in the study. The study was retrospective in nature and the principles outlined in the Declaration of Helsinki were followed during the study. The primary endpoint compared between the two groups was the extent of repigmentation achieved on different sites of body and adverse effects from treatment. Secondary endpoints compared included total number of doses, cumulative dose needed for complete repigmentation and number of doses needed for onset of repigmentation. There were 82.6% responders in Group A and 76.3% in Group B who had achieved at least 50% repigmentation. Excellent response (75%-100% repigmentation) was achieved in 68.1% lesions in Group A and 46.4% lesions in Group B. Patients in Group A needed less number of doses (13.75 vs. 19.37) and less cumulative dose (6.14 vs. 7.69 J/cm2 ) to achieve complete or near complete repigmentation. Adverse effects were negligible in both groups. Targeted phototherapy with EL demonstrated better repigmenting efficacy than TUVB in vitiligo.

Synergistic Effects of the 308-nm Excimer Light and Topical Calcipotriol for the Treatment of Chronic Hand Eczema: A Randomized Controlled Study.

BACKGROUND: Though topical corticosteroid is a standard treatment for chronic hand eczema (CHE), it can cause many adverse effects. Topical calcipotriol and monochromatic 308-nm excimer light (MEL) are new alternative therapies for several dermatoses, including CHE. OBJECTIVE: This study aims to compare the efficacy of the combination of MEL and topical calcipotriol versus topical calcipotriol alone. METHODS: One hand of the participants was randomly assigned to be irradiated with MEL twice weekly and topical calcipotriol applied twice daily while the other hand was assigned to receive only topical calcipotriol twice daily for 8 weeks. Then, only petrolatum ointment was applied during the 4-week follow-up period. Hand Eczema Severity Index (HECSI) and modified Total Lesion Symptom Score were assessed by a blinded investigator, and a visual analogue scale score of itching symptoms was graded by the participants. RESULTS: In total, 36 hands from 18 subjects completed the protocol. On the combination-treated sides, the mean HECSI score was significantly reduced by 25% (p = 0.015) from the 4th week. Then, it was gradually decreased to 57 and 65% (p < 0.001) at the 8th week and at the follow-up visit, respectively. For the monotherapy-treated sides, the mean HECSI score was reduced to 41% (p = 0.001) and 49% (p < 0.001) at the 8th and 12th week, accordingly. At the end of the treatment period, itching scores were significantly decreased by around 64% (p < 0.001) and 51% (p = 0.002) on the combination-treated and the monotherapy-treated sides. No serious and persistent adverse reactions were found. CONCLUSION: The combined MEL and topical calcipotriol may be considered as an alternatively effective treatment for CHE.

Comparative efficacy between localized 308-nm excimer light and targeted 311-nm narrowband ultraviolet B phototherapy in vitiligo: A randomized, single-blind comparison study.

BACKGROUND: There are limited data to compare efficacy between recent 308-nm excimer and conventional 311-nm narrowband ultraviolet B (NB-UVB) light in the treatment of vitiligo. OBJECTIVE: To compare efficacy between 308-nm excimer light and 311-nm NB-UVB in patients with symmetrical vitiligo lesions. METHODS: Thirty-six symmetrically paired vitiligo lesions on the same anatomical area were enrolled. One side of the symmetrical lesions was treated with localized 308-nm excimer light, and the opposite side was treated with targeted 311-nm NB-UVB assigned randomly by computer. All lesions were treated with the same protocol, for 48 sessions. Repigmentation was evaluated using Vitiligo Area Scoring Index (VASI) and grading the repigmentation was carried out with three independent investigators. RESULTS: Thirty-six symmetrically vitiligo lesions were randomly treated, one side with 308-nm excimer light and the opposite side with 311-nm NB-UVB. After 48 sessions, a significantly lower VASI score and a higher grade of repigmentation were observed in 308-nm excimer light-treated side (P < .001). Nine lesions (25%) treated with 308-nm excimer light and only five lesions (13.89%) treated with 311-nm NB-UVB achieved excellent repigmentation. The 308-nm excimer light and 311-nm NB-UVB-treated sides rapidly obtained 25% repigmentation within a mean of 19.42 sessions and 26.25 sessions, respectively (P = .002). There was no significant difference in mean cumulative UV dosage (P = .065). Side effect as phototoxicity was similar in both sides (P = .08). CONCLUSION: Localized 308-nm excimer light appears to be more effective and also more rapidly induces repigmentation than targeted 311-nm NB-UVB for treatment of vitiligo.

A Lower Irradiation Dose of 308 nm Monochromatic Excimer Light Might Be Sufficient for Vitiligo Treatment: A Novel Insight Gained from In Vitro and In Vivo Analyses.

A 308 nm monochromatic excimer light (MEL) is widely used to treat patients with vitiligo. However, dose optimization still needs to be clarified. This study aimed to obtain objective evidence regarding various doses of MEL irradiation, induced cell level changes in vitro, and skin level alterations in vivo. Cultured human keratinocytes were irradiated with MEL using various doses. After irradiation at low doses, stem cell factor, endothelin-1, and glycoprotein nonmetastatic melanoma protein B, factors that activate and protect melanocytes, were found to be significantly elevated in keratinocytes. After irradiation using medium and high doses, inflammatory cytokines were induced. The amount of ATP released and the level of inflammasome activation, which are known to be related to interleukin-1ß activation, were also increased. The back skin of guinea pigs and mice were irradiated with MEL at varying doses. After irradiation, an increase of epidermal melanin and epidermal melanocytes was confirmed, using the minimal erythemal dose or less. In rhododendrol-induced leukoderma guinea pigs, a much lower dose of MEL irradiation was effective, when compared with the effective dose for control guinea pigs. Our results suggest that a lower irradiation dose of MEL might be sufficient and more suitable for repigmentation in vitiligo treatment.

Excimer light therapy in childhood segmental vitiligo: Early treatment gives better results.

Segmental vitiligo (SV) is considered to be relatively less responsive form of vitiligo to medical treatment. While excimer light (EL) has shown great promise in treating localized vitiligo especially on face and neck, its efficacy in SV is not reported so commonly. We conducted a retrospective study on patients of childhood SV who had received EL therapy from January 2016 to December 2018 at our institute. Data of all such cases who had received at least 10 doses of EL treatment or achieved complete repigmentation were selected for analysis. Records of 26 children with SV satisfied the selection criteria. Excellent response (>75% repigmentation) was documented in 65.4% (17/26) patients with 7.7% (2/26) patients showing partial (50%-75%) repigmentation. Response to treatment was seen to correlate inversely with the duration of SV. Patients with SV of <6 months reported better results with all 10 cases achieving complete or near complete (>75%) repigmentation. In contrast, only 44% patients (7/16) with disease duration of >6 months were seen to have achieved >75% repigmentation.

Effects of 308 nm excimer light treatment on the skin microbiome of atopic dermatitis patients.

BACKGROUND: The skin microbiome has been implicated in the pathophysiology of atopic dermatitis (AD). Although 308 nm excimer light treatment is an effective phototherapy for AD, its effects on the skin microbiome currently remain unclear. Therefore, we investigated the effects of the excimer light treatment on the skin bacterial and fungal microbiome of lesional skin of AD. METHODS: Swab samples were collected from 11 healthy controls, non-lesional and lesional skin of 11 AD patients. The excimer light treatment was administered to the lesional skin. The composition of the skin microbiome, the clinical score and skin barrier function of the lesional skin were examined before and after the treatment. The composition of the skin microbiome was determined by sequencing bacterial 16S and fungal internal transcribed spacer regions. RESULTS: The excimer light treatment significantly changed the composition of the bacterial microbiome in the lesional skin of AD, as well as improved the clinical score and skin barrier function. The treatment increased the relative abundance of the phylum Cyanobacteria and decreased that of the phylum Bacteroidetes in lesional skin. At the species level, the treatment significantly decreased the relative abundance of Staphylococcus aureus (S aureus) in lesional skin. There was also a significant correlation between the reduction of S aureus and improvement of the clinical outcomes. CONCLUSION: Our findings suggest that alterations of the skin microbiome with excimer light treatment, specifically the decrease in the abundance of S aureus, are partly involved in the improvement of AD lesions.

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.

Comparative study between excimer light and topical antioxidant versus excimer light alone for treatment of vitiligo.

BACKGROUND: Vitiligo is an acquired idiopathic cutaneous disease characterized by pearly white patches of variable shapes and sizes. Various medical and surgical therapeutic options have been proposed to achieve repigmentation; phototherapy is one of the most efficient options. Topical therapies have been a mainstay of vitiligo treatment, with or without phototherapy. AIM OF THE WORK: To compare the efficacy of combined topical antioxidant hydrogel and excimer light versus excimer light alone in treating vitiligo. PATIENTS AND METHODS: Thirty patients were included in this comparative, prospective, randomized study. For each patient, at least 2-4 vitiliginous macules were randomly selected and treated while an untreated vitiliginous macule served as control. Lesions were divided into two groups: Group A received combination therapy of daily topical antioxidant plus excimer light, while Group B received only excimer light. Lesions were treated twice a week for a maximum of 24 sessions. Initial fluencies were adjusted individually according to the minimal erythema dose in vitiliginous skin. Efficacy based on repigmentation percentages were blindly evaluated by two independent physicians. RESULTS: Group A lesions showed significant efficacy than group B (p < 0.001), specially on treating UV-sensitive lesions with no side effects. CONCLUSION: Topical antioxidant and excimer light represents a valuable, effective therapy for localized vitiligo.

Monochromatic excimer light versus combination of topical steroid with vitamin D3 analogue in the treatment of nonsegmental vitiligo: a randomized blinded comparative study.

Vitiligo is a difficult disease to treat, socially stigmatizing its patients. Monochromatic excimer light (MEL) was developed for use in dermatology and adapted for the treatment of vitiligo. Comparing the efficacy of MEL versus topical combination therapy of vitamin D3 analogue and steroid in the treatment of nonsegmental vitiligo. Forty-four patients with localized and stable nonsegmental vitiligo participated in the present study. In each patient, two lesions were selected and divided randomly into two groups, group A was treated with daily topical combination of calcipotriol and betamethasone and group B was treated with biweekly sessions of MEL for 3 months. Efficacy based on repigmentation percentages were blindly evaluated by two independent physicians and patient's satisfaction. There was significant improvement in both treatment modalities at the end of the study, but without significant differences in both groups. There was a significant difference between both groups regarding the onset of repigmentation (p-value < 0.05), whereas group B showed early sign of repigmentation in first 4 weeks of treatment in 16 patients versus 7 patients in group A. Both treatment modalities offered encouraging results and both are promising lines for the treatment of vitiligo.

308-nm excimer light is effective for palmoplantar pustulosis regardless of the presence or absence of focal infection: Single-center real-world experience of treatment for palmoplantar pustulosis.

Palmoplantar pustulosis (PPP) is relatively rare and recognition of PPP is different in different countries. Therefore, real-world data are limited. Local phototherapy for the palms and the soles is commonly used to treat PPP due to tolerable safety. However, data on the effectiveness of 308-nm excimer light are limited. In our study, we retrospectively investigated the effectiveness of treatments for PPP, especially phototherapy (308-nm excimer light), in our department. In addition, we examined whether smoking status and focal infection affected responsiveness to treatment of PPP. Patients who were diagnosed with PPP by board-certified dermatologists and visited our hospital from April 2015 to August 2018 were analyzed in this study. We collected data on PPP area severity index (PPPASI) before treatment. We also collected data on PPPASI in May to August 2018 as "after treatment" from all patients. Patients who received any treatment for less than 3 months were excluded. Nineteen patients (16 women and three men) were analyzed in this study. In patients treated with phototherapy (n = 12), PPPASI significantly decreased from a mean ± SD of 16.5 ± 10.3 to 4.5 ± 3.6 (p = 0.004), whereas it did not in patients treated without phototherapy (n = 7). Patients who quit smoking showed a significant decrease in PPPASI after treatment (16.8 ± 12.7 to 2.4 ± 2.9, p = 0.008). Regarding focal infection, in patients treated without phototherapy, the reduction rate of PPPASI was significantly lower in patients with focal infection than in those without focal infection (17.7 ± 21.5%, 71.1 ± 19.3%, p = 0.035), indicating that focal infection is associated with intractability. Meanwhile, in patients treated with phototherapy, PPPASI decreased regardless of the presence or absence of focal infection. In conclusion, our study demonstrated the effectiveness of local phototherapy consisting of 308-nm excimer light, regardless of focal infection. Patients who quit smoking were responsive to any treatment, indicating the importance of smoking cessation.

Efficacy and safety of 308-nm Excimer lamp combined with Tacrolimus 0.1% ointment vs Tacrolimus 0.1% ointment as monotherapy in treating children with limited vitiligo: a randomized controlled trial.

OBJECTIVE: This study aims to assess the efficacy and safety of combining the 308-nm Excimer lamp with Tacrolimus 0.1% ointment, compared to Tacrolimus 0.1% ointment monotherapy, for treating pediatric vitiligo involving less than 10% of the body surface area. METHODS: Fifty pediatric patients with vitiligo were randomly assigned to two groups. Group A received Tacrolimus 0.1% ointment twice daily and Excimer light at 308-nm twice weekly, while Group B received Tacrolimus 0.1% ointment alone, administered twice daily. Repigmentation percentages were evaluated after 30, 90, and 180 days using the rule of nine. RESULTS: Group A exhibited a significant improvement in repigmentation, increasing from 10% after one month to 65% after six months. In contrast, Group B observed an increase from 10% to 30% over the same timeframe. The efficacy of the treatment was significantly higher in Group A at both the 3-month and 6-month follow-up points (p-value < .001). Moreover, Group A achieved notably higher repigmentation rates in the face, trunk, and lower limbs. CONCLUSION: The combination of Tacrolimus and the 308-nm excimer lamp yielded superior repigmentation results compared to Tacrolimus monotherapy in pediatric vitiligo patients. This combined approach may offer an effective new treatment protocol for pediatric vitiligo.

Weekly phototherapy is an effective therapy for patients with vitiligo.

The current strategies for the treatment of vitiligo using phototherapy usually involve treatment for two-three times per week; however, in practice, the number of patient sessions does not meet this standard. The present study found that phototherapy once a week was also effective. The present study was designed to examine the efficacy of weekly light therapy. For this purpose, 296 patients with vitiligo were included and divided into five sub-samples of the neck, face, trunk, extremities and scalp according to the site of phototherapy, and were treated once or twice weekly with phototherapy. The difference in efficacy between phototherapy performed once and twice weekly was observed using a Chi-squared test. It was concluded that there was a minimal difference between phototherapy performed twice weekly compared to once weekly for the treatment of vitiligo on the face, neck, torso, limbs and scalp. Thus, phototherapy once a week is valid for the treatment of vitiligo, although weekly light therapy takes longer to restore color for the first time.

Idiopathic Guttate Hypomelanosis Treated with 308-nm Excimer Light and Topical Bimatoprost.

Idiopathic guttate hypomelanosis (IGH) is an acquired pigmentary disorder that is characterized by the presence of multiple hypopigmented macules on the shins and forearms. Albeit asymptomatic, it can cause considerable cosmetic anxiety. The pathogenesis is not fully understood and to date, there have been no successful treatments. We report a case of a 48-year-old female who presented with an 8-year history of multiple hypopigmented macules on both legs, typical of IGH. She previously failed to respond to topical pimecrolimus. She received targeted phototherapy with an excimer lamp (308 nm, 250-480 mJ), and a small patch was treated once daily with topical bimatoprost, in addition to the excimer lamp. After five sessions, better improvement was noted on the combination treatment patch; she received combination treatments for further six sessions. Good repigmentation has been achieved on the smaller macules. The larger depigmented macules continue to improve with further treatments. A combination of excimer light with topical bimatoprost appears to be a promising potential treatment option for IGH, a condition where management options are otherwise limited.

Additional effect of excimer light therapy in patients with psoriasis under other therapies.

Excimer light is an effective therapy for psoriasis resulting in faster clearance and a longer remission. We studied its additional effect in patients with psoriasis under other therapies. Subjects were composed of 261 patients with psoriasis, all of which were treated with topical application of steroid and vitamin D mixed ointment. Other therapies were composed of apremilast and biologics. PASI 100 rate were evaluated until 12 months after the start of its therapy. PASI 100 rate was elevated from 13 patients (5.0%) to 34 patients (13.0%, P < 0.01). Twenty-one of 63 patients (33.3%, P < 0.01) not reaching PASI 100 reached it after excimer light therapy. The addition of excimer light therapy in each treatment showed no significant difference compared with that before addition. Irradiation amount in patients with guselkumab (822 ± 259 mJ) was significantly smaller that with excimer only (1370 + 731 mJ) and that with IL-17 (1747 ± 749 mJ). In addition, irradiation amount in patients reached PASI-100 in Guselkumab (717 ± 75 mJ) which was significantly smaller that in the excimer only group (1530 ± 450 mJ). Additional effect of excimer light therapy in psoriasis, especially in patients with guselkumab, was speculated.