Controlled study of excimer and pulsed dye lasers in the treatment of psoriasis

Modeling pulsed dye laser treatment of psoriatic plaques by combining numerical methods and image-derived lesion morphologies

OBJECTIVES

Knowledge of the physical effects of pulsed dye laser (PDL) treatment of psoriatic lesions is essential in unraveling the remedial mechanisms of this treatment and hence also in maximizing in its disease-modifying potential. Therefore, the main objective of this study was to provide estimates of these physical effects (for laser wavelengths of 585 and 595 nm), with the aim of identifying pathogenic processes that may be affected by these conditions.

METHODS

We modeled the laser light propagation and subsequent photothermal heating by numerically solving the transient diffusion and heat equations simultaneously. To this end, we used the finite element method in conjunction with an image-derived psoriatic lesion morphology (which was defined by segmenting blood vessels from a confocal microscopy image of a fluorescently labeled section of a 3 mm punch biopsy of a psoriatic lesion). The resulting predictions of the generated temperature field within the lesion were then used to assess the possibility of stalling or arresting some suspected pathogenic processes.

RESULTS

According to our results, it is conceivable that perivascular nerves are thermally denatured, as almost all locations that reach 60°C were found to be within 18 µm (at 585 nm) and 11 µm (at 595 nm) of a blood vessel wall. Furthermore, activation of TRPV1 and TRPV2 channels in perivascular neuronal and immune cells is highly likely, since a critical temperature of 43°C is generated at locations within up to 350 µm of a vessel wall (at both wavelengths) and sustained for up to 700 ms (at 585 nm) and 40 ms (at 595 nm), while a critical temperature of 52°C is reached by locations within 80 µm (at 585 nm) and 30 µm (at 595 nm) of a vessel wall and sustained for up to 100  ms (at 585 nm) and 30 ms (at 595 nm). Finally, we found that the blood vessel coagulation-inducing temperature of 70°C is sustained in the vascular epithelium for up to 19 and 5 ms at 585 and 595 nm, respectively, rendering partial or total loss of vascular functionality a distinct possibility.

CONCLUSIONS

The presented approach constitutes a useful tool to provide realistic estimates of the photothermal effects of PDL treatment of psoriatic plaques (as well as other selective photothermolysis-based treatments), yielding information that is essential in guiding future experimental studies toward unraveling the remedial mechanisms of these treatments.

Efficacy and safety of excimer light (308 nm) in the treatment of pityriasis lichenoides chronica

INTRODUCTION

Pityriasis lichenoides chronica is the chronic end of the spectrum of pityriasis lichenoides which have several forms of papulosuamous conditions. Several treatments obtained complete clearance of the condition including phototherapy and specifically narrow band ultraviolet B. The Excimer light 308 is a monochromatic light that acts within the ultraviolet B wavelength and used as a targeted phototherapy in several skin conditions.

METHODS

Thirty-four patients with histopathologically diagnosed pityriasis lichenoides chronica underwent treatment with biweekly sessions of excimer light 308 nm. Treatment continued until complete clearance was obtained or to a maximum of 48 sessions (24 weeks).

RESULTS

Thirty-one patients obtained complete clearance with no recurrence till the end of the study period, two patients had partial response and only one patient showed poor response to treatment.

CONCLUSION

Excimer light can be a safe and effective treatment of pityriasis lichinoides chronica in different ages and genders.

Visible light. Part I: Properties and cutaneous effects of visible light

Approximately 50% of the sunlight reaching the Earth's surface is visible light (400-700 nm). Other sources of visible light include lasers, light-emitting diodes, and flash lamps. Photons from visible light are absorbed by photoreceptive chromophores (e.g., melanin, heme, and opsins), altering skin function by activating and imparting energy to chromophores. Additionally, visible light can penetrate the full thickness of the skin and induce pigmentation and erythema. Clinically, lasers and light devices are used to treat skin conditions by utilizing specific wavelengths and treatment parameters. Red and blue light from light-emitting diodes and intense pulsed light have been studied as antimicrobial and anti-inflammatory treatments for acne. Pulsed dye lasers are used to treat vascular lesions in adults and infants. Further research is necessary to determine the functional significance of visible light on skin health without confounding the influence of ultraviolet and infrared wavelengths.

Nonvascular uses of pulsed dye laser in clinical dermatology

Lasers are fast becoming the vogue of dermatology ranging from ablative, nonablative, fractional photothermolysis to vascular lasers. There are a range of vascular lasers including potassium titanyl phosphate (KTP 532 nm), pulsed dye laser (PDL -595 nm), diode (810 nm), and Nd:YAG (1064 nm). PDL is a laser that emits yellow light using Rhodamine dye as it is lasing medium. Typical vascular lesions which are treated by PDL include port wine stain, hemangioma, telangiectasia, spider angioma, and rosacea. This article focuses on the use of PDL beyond primary vascular conditions. We review the evidence, or lack thereof, of the use of PDL in acne vulgaris, scars, striae, warts, molluscum, psoriasis, rejuvenation, basal cell carcinoma (BCC), and miscellaneous dermatological sequelae.

A clinical review of phototherapy for psoriasis

Psoriasis is an autoimmune inflammatory skin disease. In the past several decades, phototherapy has been widely used to treat stable psoriatic lesions, including trunk, scalp, arms and legs, and partial nail psoriasis. A variety of light/lasers with different mechanisms of action have been developed for psoriasis including ultraviolet B (UVB), psoralen ultraviolet A (PUVA), pulsed dye laser (PDL), photodynamic therapy (PDT), intense pulsed light (IPL), light-emitting diodes (LED), and so on. Because light/laser each has specific therapeutic and adverse effects, it is important to adequately choose the sources and parameters in management of psoriasis with different pathogenic sites, severities, and duration of the disorder. This review aims at providing most updated clinic information to physicians about how to select light/laser sources and individual therapeutic regimens. To date, UV light is primarily for stable plaque psoriasis and PDL for topical psoriatic lesions with small area, both of which are safe and effective. On the other hand, PUVA has better curative effects than UVB for managing refractory psoriasis plaques, if its side effects can be better controlled. PDL provides optimal outcomes on nail psoriasis compared with other lasers. Although the trails of low-level light/laser therapy (LLLT) are still small, the near infrared (NIR) and visible red light with low energy show promise for treating psoriasis due to its strong penetration and encouraging photobiomodulation. IPL is rarely reported for psoriasis treatment, but PDT-IPL has been found to offer a moderate effect on nail psoriasis. In brief, various phototherapies have been used either in different combinations or as monotherapy. The modality has become a mainstay in the treatment of mild-to-moderate psoriasis without systemic adverse events in today's clinical practice.

Single Blinded Left-to-Right Comparison Study of Excimer Laser Versus Pulsed Dye Laser for the Treatment of Nail Psoriasis

Introduction

Nail psoriasis is relatively difficult to treat. Excimer laser has been approved for the treatment of psoriasis since 2000. Pulsed dye laser (PDL) in psoriasis therapy has shown good response rates, with extended remissions. This is the first study assessing both the excimer and PDL lasers in nail psoriasis.

Methods

In a comparison study, excimer laser versus PDL for the treatment of nail psoriasis was evaluated in 42 patients. The right hand nails were treated with excimer laser twice weekly and the left hand nails were treated with PDL once every 4 weeks, for total 12 weeks. The patients were then followed up after a further 12 weeks. Nail Psoriasis Severity Index (NAPSI) scores were recorded at baseline, weeks 4, 8, and 12, and then at week 24. Patients were also asked to grade the clinical response to each treatment.

Results

A total of 304 nail changes, 148 with excimer laser and 156 with PDL, were treated. The mean NAPSI score in nails treated with excimer laser was 29.8 at baseline, reduced to 16.3 at week 24. In PDL-treated nails, the NAPSI scores dropped from 29.5 at baseline to 3.2 at week 24. NAPSI improvement was significantly greater in PDL than excimer (P = 0.001; Wilcoxon signed-rank test). Thirty-four (81%) hands achieved NAPSI-50, and 23 (55%) achieved NAPSI-75 at week 12, while complete nail recovery was shown in 6 (14%) hands treated with PDL. Regarding the hands treated with excimer laser, only 16 (38%) hands achieved NAPSI-50, while no hands achieved NAPSI-75 at week 12. In general, subungual hyperkeratosis and onycholysis improved significantly, while nail pitting was least responsive. Oil drops and splinter hemorrhages showed moderate response.

Conclusions

When compared to excimer laser, PDL demonstrated a good response for treating nail psoriasis, with minimal side effects.

Electronic supplementary material

The online version of this article (doi:10.1007/s13555-014-0057-y) contains supplementary material, which is available to authorized users.

Inverse psoriasis involving genital skin folds: successful therapy with dapsone

Introduction

Inverse psoriasis is a rare form of psoriasis that affects between 3% and 7% of the patients with psoriasis. It can comprise genital skin folds as part of genital psoriasis, and it is one of the most commonly seen dermatoses of this area. There are few evidence-based studies about the treatment of intertriginous psoriasis involving genital skin folds.

Case Presentation

The authors present a 42-year-old female patient with erythematous plaques in the vulva, groin, and perianal region. The patient had previously received a broad range of topical and systemic therapies that had to be discontinued due to ineffectiveness or side effects. She was treated with 100 mg dapsone daily for 10 months, showing a significant improvement of her cutaneous and mucous lesions. Complete clearance of psoriatic lesions was observed after 4 weeks of treatment. She has remained in remission for up to 2 years, using only topical therapy with tacrolimus 0.1% and calcipotriol.

Discussion

Genital psoriasis is a skin disease that causes great discomfort. It is important to include examination of the genital region and to adopt this conduct in daily clinical practice. Research in this field is still poor, making no discrimination between flexural and genital psoriasis, and is based on case series and expert opinion; therefore, empirical recommendations for the treatment of genital psoriasis remain. Dapsone has been shown to be an effective and convenient alternative for the treatment of inverse psoriasis in genital skin folds, which can provide effective control of the disease. Further studies are required to determine the efficacy and safety of current therapies, and to decide whether dapsone therapy should be considered in the management of this form of psoriasis when topical and other systemic agents are not effective.

S3 - Guidelines on the treatment of psoriasis vulgaris (English version). Update

Psoriasis vulgaris is a common and often chronic inflammatory skin disease. The incidence of psoriasis in Western industrialized countries ranges from 1.5% to 2%. Patients afflicted with severe psoriasis vulgaris may experience a significant reduction in quality of life. Despite the large variety of treatment options available, surveys have shown that patients still do not received optimal treatments. To optimize the treatment of psoriasis in Germany, the Deutsche Dermatologi sche Gesellschaft (DDG) and the Berufsverband Deutscher Dermatologen (BVDD) have initiated a project to develop evidence-based guidelines for the management of psoriasis. They were first published in 2006 and updated in 2011. The Guidelines focus on induction therapy in cases of mild, moderate and severe plaque-type psoriasis in adults including systemic therapy, UV therapy and topical therapies. The therapeutic recommendations were developed based on the results of a systematic literature search and were finalized during a consensus meeting using structured consensus methods (nominal group process).

Pulsed dye laser in the treatment of nail psoriasis

BACKGROUND

The treatment options for nail psoriasis have been limited, and the management of nail psoriasis has been challenging for physicians.

OBJECTIVES

To evaluate the effect of pulsed dye laser (PDL) in the treatment of nail psoriasis.

METHODS

Psoriatic nails of five patients were treated using PDL (595 nm) once monthly for 3 months. The pulse duration was 1.5 ms, the beam diameter was 7 mm, and the laser energy was 8.0 to 10.0 J/cm(2). Clinical efficacy was statistically evaluated according to Nail Psoriasis Severity Index (NAPSI) score differences before and after the treatment.

RESULTS

Statistical analysis of NAPSI scores before and after treatment showed significant difference (p<.05, paired t-test). The nail bed lesions, particularly onycholysis and subungual hyperkeratosis, responded best to the treatment.

LIMITATIONS

Limitations include the lack of blinding and comparison and the small number of patients.

CONCLUSION

PDL might be an alternative treatment for nail psoriasis. The authors have indicated no significant interest with commercial supporters.

Emerging drugs for psoriasis

BACKGROUND

Psoriasis is a relatively common, chronic and disabling skin disease, due to a disturbed proliferation and differentiation of keratinocytes, accompanied by vascular alterations and infiltration of inflammatory cells with a local T(H)1-type cytokine immune response. There is no cure, but several treatment options are available.

OBJECTIVE

The treatment of psoriasis is far from being satisfactory, due to the impractical modalities of topical treatment and the suboptimal safety profile of the systemic treatments available. In the last few years, parallel to an improved understanding of the disease pathogenesis, there has been a boosting of research in new agents for the treatment of psoriasis. These new agents are the focus of this paper.

METHODS

After a short review of the treatment options already available (mainly based on the available systematic reviews), we focused on agents that are still in clinical development (Phase I - III) and have not yet entered the market. For the purpose of this study, we systematically searched the main registries of ongoing trials up to August 2008.

RESULTS/CONCLUSION

The field is very dynamic, with both immunopharmacology of recombinant DNA techniques and more traditional small-molecule pharmacology actively delivering new agents. With the increasing number of new options, there is a need for research systems that enable to effectively collect long-term safety data on treated patients.

Laser treatment of acne, psoriasis, leukoderma, and scars

Lasers frequently are used by dermatologists for their multiple aesthetic applications, but they also can be used to treat a variety of medical dermatology conditions. Conditions such as acne vulgaris, psoriasis, and vitiligo can all be successfully treated with laser, thereby providing the patient with additional therapeutic options. Lasers have also been used for years to improve the appearance of scars. The newer fractionated lasers have been especially effective in enhancing the clinical outcomes of scar revision.

Psoriasis in the elderly

Psoriasis is one of the most common chronic skin diseases, and unprecedented increases in the elderly population will make diagnosis and management of geriatric psoriasis increasingly important. Management of psoriasis in the elderly requires consideration of several important factors. Many commonly prescribed drugs can precipitate psoriasis or aggravate pre-existing psoriasis. In addition, elderly patients are at increased risk of adverse drug reactions due to polypharmacy, adverse drug–drug interactions, adverse drug–disease interactions, incorrect use of medication and concomitant comorbidities. Psoriasis is a highly variable disease that requires individualized treatment. The major classes of topical medications include topical corticosteroids, coal tar preparations, calcipotriol, tazarotene and salicylic acid. Phototherapy, including narrowband ultraviolet B, photochemotherapy, psoralen ultraviolet A and excimer laser treatment, can be effective in properly selected patients. Systemic therapy for psoriasis in the elderly should be reserved for severe, extensive cases that have failed to respond to topical treatment, and may include methotrexate, systemic retinoids and immunotherapy.

Pulsed dye laser: what's new in non-vascular lesions?

BACKGROUND AND OBJECTIVE

In dermatology, the pulsed dye laser (PDL) is the therapeutic instrument of choice for treating most superficial cutaneous vascular lesions. In addition, clinical experience over the last decade allowed us to treat patients with an ever increasing number of non-vascular indications. The purpose of this report is to summarize and critically appraise the scientific evidence that support the role of PDL in treating non-vascular skin lesions.

METHODS

A literature-based study has been conducted, including the review of publications over the period January 1995 to December 2006, using the Medline Database. We also included our own experience in managing non-vascular lesions with the PDL. Four sets of preoperative and postoperative photos are presented.

RESULTS

For viral skin lesions, PDL proved to be an alternative to other therapy options. This applies particularly to periungual warts and mollusca contagiosa. The mechanism of PDL with inflammatory dermatoses has not yet been elucidated. The effect seems to be better if there is a vascular component to the disease. With most of these indications (such as psoriasis and acne), PDL currently plays a rather minor or complementary role. Regarding collagen remodelling (hypertrophic scars, keloids, stretch marks, and skin rejuvenation), the question of whether a therapy makes sense or not has to be decided from case to case.

CONCLUSION

With PDL, it is possible to achieve good results with numerous, partly less well-known indications (i.e. lupus erythematosus). With other diseases, PDL has so far been considered to be a complementary therapy method or to be in an experimental state.

Current and future management of psoriasis

Management of psoriasis begins with identification of the extent of cutaneous disease. However, a holistic, contractual approach to treatment is encouraged, with particular reference to psychosocial disability and quality-of-life issues. The presence of psoriasis on palms, soles, body folds, genitals, face, or nails, and concomitant joint disease, are also important when considering treatment options. An evidence-based approach is essential in delineating differences between the many available treatments. However, archaic approaches, especially combinational ones, are routinely used by some clinicians, with inadequate prospective or comparative evidence. Treatments currently available are: topical agents used predominantly for mild disease and for recalcitrant lesions in more severe disease; phototherapy for moderate disease; and systemic agents including photochemotherapy, oral agents, and newer injectable biological agents, which have revolutionised the management of severe psoriasis. Other innovative treatments are undergoing clinical studies, with the aim of maintaining safe, long-term control of the condition.

Pulsed dye laser versus treatment with calcipotriol/betamethasone dipropionate for localized refractory plaque psoriasis: effects on T-cell infiltration, epidermal proliferation and keratinization

BACKGROUND

Selective photothermolysis of diseased capillaries by pulsed dye laser (PDL) treatment has been described as a mechanism for long-lasting clearance of psoriatic plaques.

AIM

To evaluate PDL and a two-compound formulation of calcipotriol/betamethasone dipropionate ointment for the treatment of localized, recalcitrant plaque psoriasis.

METHODS

Eight psoriatic patients were treated for 4 weeks with both PDL and topical calcipotriol/betamethasone dipropionate in an open, intra-patient, left-right comparison. Biopsies were analyzed for T-cell subsets, cells expressing NK-receptors, epidermal proliferation, differentiation and epidermal thickness.

RESULTS

After active treatment, both treatments showed statistically significant but comparable improvements of T-cell subsets, epidermal proliferation, differentiation and epidermal thickness. In line with the clinical results, after an 8-week follow-up period statistically significant further reductions were observed for dermal CD3(+), CD4(+), CD45RO(+), CD2(+) T cells, epidermal CD3(+), CD8(+), CD45RO(+), CD2(+), CD25(+) T cells and the epidermal parameters for the PDL-treated plaques, in contrast to the topically treated plaques.

CONCLUSION

After 8 weeks of follow-up, PDL treatment for localized and recalcitrant plaque psoriasis resulted in persistent reductions of activated and memory effector T-helper cells in the dermis, cytotoxic T cells in the epidermis, and normalization of epidermal proliferation and keratinization, in contrast to treatment with calcipotriol/betamethasone dipropionate ointment.