Immunohistochemical evaluation of psoriatic plaques following selective photothermolysis of the superficial capillaries

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.

Subminute thermal damage to cell types present in the skin

INTRODUCTION

Psoriasis is characterized by an increase in the proliferation of keratinocytes and nerve fiber activity, contributing to the typical skin lesions. Pulsed Dye Laser (PDL) treatment is effective for the treatment of psoriatic lesions but its mechanism remains unclear. One hypothesis is that PDL causes thermal damage by the diffusion of heat to neighboring structures in lesional skin. There is limited information on the thermal sensitivity of these neighboring skin cells when exposed to hyperthermia for durations lasting less than a minute. Our study aimed to investigate the cell-specific responses to heat using sub-minute exposure times and moderate to ablative hyperthermia.

MATERIALS AND METHODS

Cultured human endothelial cells, smooth muscle cells, neuronal cells, and keratinocytes were exposed to various time (2-20 sec) and temperature (45-70 °C) combinations. Cell viability was assessed by measuring intracellular ATP content 24 h after thermal exposure and this data was used to calculate fit parameters for the Arrhenius model and CEM43 calculations.

RESULTS

Our results show significant differences in cell survival between cell types (p < 0.0001). Especially within the range of 50-60 °C, survival of neuronal cells and keratinocytes was significantly less than that of endothelial and smooth muscle cells. No statistically significant difference was found in the lethal dose (LT50) of thermal energy between neuronal cells and keratinocytes. However, CEM43 calculations showed significant differences between all four cell types.

CONCLUSION

The results imply that there is a cell-type-dependent sensitivity to thermal damage which suggests that neuronal cells and keratinocytes are particularly susceptible to diffusing heat from laser treatment. Damage to these cells may aid in modulating the neuro-inflammatory pathways in psoriasis. These data provide insight into the potential mechanisms of PDL therapy for psoriasis and advance our understanding of how thermal effects may play a role in its effectiveness.

Effects of pulsed dye laser treatment in psoriasis: A nerve-wrecking process?

Pulsed dye laser (PDL) therapy can be effective in treating psoriasis, with a long duration of remission. Although PDL therapy, albeit on a modest scale, is being used for decades now, the underlying mechanisms responsible for the long-term remission of psoriasis remain poorly understood. The selective and rapid absorption of energy by the blood causes heating of the vascular wall and surrounding structures, like perivascular nerves. Several studies indicate the importance of nerves in psoriatic inflammation. Interestingly, denervation leads to a spontaneous remission of the psoriatic lesion. Among all dermal nerves, the perivascular nerves are the most likely to be affected during PDL treatment, possibly impairing the neuro-inflammatory processes that promote T-cell activation, expression of adhesion molecules, leukocyte infiltration and cytokine production. Repeated PDL therapy could cause a prolonged loss of innervation through nerve damage, or result in a 'reset' of neurogenic inflammation after temporary denervation. The current hypothesis provides strong arguments that PDL treatment affects nerve fibres in the skin and thereby abrogates the persistent and exaggerated inflammatory process underlying psoriasis, causing a long-term remission of psoriasis.

A comprehensive review on invasomal carriers incorporating natural terpenes for augmented transdermal delivery

Background

Transdermal drug delivery is one of the most widely used drug administration routes, which offer several advantages over other routes of drug delivery. The apical layer of the skin called the stratum corneum is the most dominant obstacle in the transdermal drug delivery, which restricts the passage of drugs across the skin. Considerable strategies have been applied to enhance the rate of permeation across the epithelial cells; however, the most widely used strategy is the use of sorption boosters, also known as permeation enhancers.

Main body

Terpenes were considered as efficient skin permeation enhancers and are generally recognized as safe as per Food and Drug Administration. Terpenes improve the permeability of drugs either by destructing the stratum corneum’s tightly packed lipid framework, excessive diffusivity of drug in cell membrane or by rampant drug partitioning into epithelial cells. Various vesicular systems have been developed and utilized for the transdermal delivery of many drugs. Invasomes are one such novel vesicular system developed which are composed of phospholipids, ethanol and terpenes. The combined presence of ethanol and terpenes provides exceptional flexibility to the vesicles and improves the permeation across the barrier offered due to the stratum corneum as both ethanol and terpenes act as permeation enhancers. Therefore, utilization of invasomes as carriers to facilitate higher rate of drug permeation through the skin can be a very useful approach to improve transdermal drug delivery of a drug.

Conclusion

The paper focuses on a broad updated view of terpenes as effective permeation enhancers and invasomes along with their applications in the pharmaceutical formulations.

Advances in phototherapy for psoriasis and atopic dermatitis

Introduction: Phototherapy has long been used for the treatment of inflammatory skin diseases, such as psoriasis and atopic dermatitis. The most frequent treatment approach utilizes ultraviolet (UV) light, however, recently, different lasers and low-level light therapies (LLLT) emitting wavelengths in the spectrum of the visible light have also been tried for the treatment of inflammatory skin diseases with variable success.Areas covered: This review provides an update on the different forms of phototherapy used for the treatment of psoriasis and atopic dermatitis. The proposed mechanism of action of the different phototherapeutical approaches are covered, including the immunosuppressive effect of UV light, the anti-inflammatory effect of vascular lasers and the LLLT induced photobiomodulation. The clinical efficacy of the different treatment options is also discussed.Expert opinion: Based on the efficacy and safety, NB-UVB represents the gold standard for treating psoriasis and atopic dermatitis. The UVB excimer laser and excimer lamp might be the best option for clearing localized therapy-resistant lesions. Home UV phototherapy systems might promote treatment adherence and better compliance of the patients. Vascular lasers, IPLs and LLLT, however, can not currently be recommended for the treatment of inflammatory skin diseases because of the lack of well-controlled studies.

Evaluation of the effect of pulsed dye laser on chronic psoriatic plaque

BACKGROUND

Psoriasis is one of the most prevalent immune mediated skin diseases. Selective vascular destruction by pulsed dye laser is considered one of effective laser treatments.

OBJECTIVE

Evaluation of the therapeutic effect of pulsed dye laser in treatment of chronic psoriatic plaque lesions and changes in human beta defensin-2(HBD-2) expression in the psoriatic patients before and after treatment, with correlation to the clinical improvement.

METHODS

Twenty patients with psoriatic plaque on right side treated by laser and another plaque on left side similar in size and its severity score served as control receiving no treatment. Each patient received 3-4 sessions of pulsed dye laser 595 nm. Follow up was done for three months.

RESULTS

There was statistically significant difference between the two psoriatic plaques (untreated and treated; A and B; p = .004). There was significant decrease in HBD-2 expression after treatment. No recurrence was observed during follow up period.

CONCLUSION

The pulsed dye laser is safe, effective, and tolerable treatment for resistant stable localized plaque psoriasis with minimal side effects and prolonged recurrence period.

Evaluation of ICAM-1 expression and vascular changes in the skin of patients with plaque, pustular, and erythrodermic psoriasis

BACKGROUND

Psoriasis is a chronic inflammatory disease. Pustular, erythrodermic, and extensive plaque psoriasis are responsible for systemic complications. Systemic capillary leak syndrome is the complication with greater progression to death and occurs due to vascular changes.

PURPOSE

The aim of this study was to evaluate vascular changes through the expression of CD34 and ICAM-1 in plaque, pustular, and erythrodermic psoriasis.

METHODS

The sample consisted of seven patients with erythrodermic psoriasis, 24 with moderate-severe plaque psoriasis, 14 with mild plaque psoriasis and 13 with pustular psoriasis. Patients were submitted to physical examination and skin biopsy for histopathological examination and immunohistochemical analysis with anti-CD34 and anti-ICAM-1 antibodies. Subsequently, tissue fragments were organized by groups using the Tissue Macroarray (TMA) technique to perform immunohistochemistry.

RESULTS

In 58 patients, analysis of vessels using anti-CD34 demonstrated vascular immunostaining in superficial dermis and between dermal papillae. There were more blood vessels in erythrodermic psoriasis, followed by plaque psoriasis. In erythrodermic psoriasis, there were small and few tortuous blood vessels with great dilatation, while plaque psoriasis presented larger vessels that were less dilated and more tortuous. There was an intense and localized expression of ICAM-1 in endothelial and lymphocytic cells in all groups, with significant differences.

CONCLUSIONS

Vascular alterations are important in psoriasis, with an increase in the number of blood vessels and ICAM-1 overexpression, especially in erythrodermic form. Therefore, vascular changes and the expression of intercellular adhesion molecules could help to diagnose the erythrodermic form of psoriasis.

Relationship between Histological and Clinical Course of Psoriasis: A Pilot Investigation by Reflectance Confocal Microscopy during Goeckerman Treatment

Alterations of the skin microvasculature are known to play an important role in the development and maintenance of psoriatic skin lesions. In this study, we investigated lesional skin in 11 psoriatic patients during a modified Goeckerman treatment using reflectance confocal microscopy (RCM) to study the relationship between clinical clearance and histological normalization of psoriatic skin and the significance of histological abnormalities on the course of disease. The treatment regimen resulted in a significant reduction of the Psoriasis Area and Severity Index (PASI) as well as capillary and papillary diameters (p < 0.0001). The capillary and papillary diameters were still enlarged when compared to those in normal skin (p < 0.001). Capillary and papillary diameters correlated with each other prior to and after treatment (correlation coefficient = 0.63 and 0.64, p = 0.01 and 0.002, respectively) but not with the PASI. Capillary and papillary diameters after treatment and percentage reduction of the PASI during treatment seemed to be better predictors for the clinical course of relapse than the PASI after treatment. These findings make the subclinical changes of psoriatic skin vessels and dermal papillae a legitimate target for treatment. Further investigations of a large group of patients are needed to evaluate the potential of RCM findings as successor of the PASI in the monitoring of psoriasis.

Quantitative comparison of angiogenesis and lymphangiogenesis in cutaneous lichen planus and psoriasis: immunohistochemical assessment

Recent experimental studies revealed that angiogenesis and lymphangiogenesis are closely related to chronic inflammation. The present study aims to evaluate quantitative changes of blood and lymphatic microcirculatory beds in cutaneous lichen planus (CLP) and psoriatic lesions using immunohistochemical analysis with antibodies to CD34, D2-40 and VEGF. Morphometric software was used to determine the area of blood and lymphatic vessels (BVA and LVA) and also the VEGF positive area. Statistical analysis of these parameters confirmed a significant enlargement of both the blood and lymphatic microcirculatory beds in psoriatic and CLP lesions. BVA in CLP lesions was increased by 56% however this augmentation was not as great as in psoriatic lesions where BVA was increased by 123%. Interestingly, LVA in psoriatic and CLP lesions was increased equally by 85%. The strongest VEGF expression was detected in psoriatic lesions, with lower, but still significant, overexpression in CLP lesions. VEGF-C was significantly increased in both psoriatic and CLP lesions in comparable level. Noticeably higher VEGF and VEGF-C expression was observed in the epidermis than in the dermis. Finally, our results indicate that the level of angiogenesis is considerably greater in psoriatic lesions than in CLP lesions, but the level of lymphangiogenesis is equal in both psoriatic and CLP lesions.

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.

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.

Molecular pathophysiology of psoriasis and molecular targets of antipsoriatic therapy

Psoriasis is a chronic inflammatory skin disease characterised by elevated red scaly plaques on specific body sites. Histologically, the plaques are defined by epidermal hyperplasia, epidermal and dermal infiltration by leukocytes, and changes in the dermal microvasculature. Differentiation and activation are disturbed in lesional psoriatic keratinocytes, and the pool of proliferating keratinocytes is increased, which is accompanied by enhanced production of proinflammatory cytokines, adhesion molecules and antimicrobial peptides. These changes in psoriatic keratinocytes are caused by altered expression of genes associated with epidermal differentiation, and by activation of signalling pathways involving signal transducer and activator of transcription 3 (STAT3), type I interferon (IFN) and mitogen-activated protein kinase (MAPK). The number of T cells, and myeloid and plasmacytoid dendritic cells (DCs) is markedly increased in psoriatic lesions. Myeloid DCs produce interleukin (IL)-23, tumour necrosis factor (TNF)-alpha and inducible nitric oxide synthase (iNOS), which are crucial cytokines in the pathogenesis of psoriasis. IL-23 stimulates the secretion of IL-22 by T helper 17 cells, and IL-22 induces epidermal hyperplasia. The crosstalk between keratinocytes and leukocytes via their proinflammatory cytokines creates the vicious circle of chronic skin inflammation seen in psoriasis. This suggests that optimal treatment of psoriasis needs to target pathogenic pathways in both leukocytes and keratinocytes.

The distinction between lesional and non-lesional skin in psoriasis vulgaris through expression of adhesion molecules ICAM-1 and VCAM-1

Psoriasis vulgaris [pv] is a systemic inflammatory skin disease affecting 2-4% population. It is well known that pv affects some parts of the skin and also whole skin as in erythrodermic form. We still do not know why in pv some parts of the skin are affected and others are not. In our hypothesis we assumed that the whole skin is in <<stand by>> position and non-lesional skin could become in every moment lesional. According to our hypothesis and also other author's research, high expression of adhesion molecules ICAM-1 and VCAM-1 in lesional as well as non-lesional skin in pv, supports this hypothesis, suggesting a significance of these molecules in pathogenesis of pv. Our hypothesis could be proved by immunohistochemical stain of ICAM-1 and VCAM-1 in lesional and non-lesional skin of pv patient in comparison with healthy skin.

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.

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.

Paediatric eczema and psychosocial morbidity: how does eczema interact with parents' illness beliefs?

BACKGROUND

Thus far there has been relatively little work on children's illness representations regarding eczema and how these relate to parental conceptualizations of their child's psychosocial health. This is important because the challenge of raising a child with a serious illness can affect many facets of a parent's everyday life and the behaviour of parents can be closely related to the health of the child.

METHODS

Two hundred and thirty-two children with eczema, asthma, eczema and asthma, and healthy controls between 7 and 12 years of age and their parents were recruited. Children were administered the Children's Illness Perception Questionnaire. Questionnaires completed by the parents were The Personality Inventory for Children and The Parental Stress Inventory.

RESULTS

Parents of children with eczema did not judge their children to have poorer psychosocial health than controls, but parents of children with eczema could not be distinguished between in terms of whether their child was significantly affected by their eczema or not.

CONCLUSIONS

This work could have important implications for the quality of life of the child and for the parent-child relationship and these implications are considered.

Comparison of the effects of pulsed dye laser, pulsed dye laser + salicylic acid, and clobetasole propionate + salicylic acid on psoriatic plaques

BACKGROUND

Studies show that pulsed dye laser (PDL) has some clinical benefits on psoriasis with a low clearance rate. In addition, it has been suggested that applying keratolytics before treatment might be helpful in PDL therapy. Topical corticosteroids remain the most commonly prescribed agents for psoriasis.

OBJECTIVE

This study was designed to compare the efficacy of the PDL treatment with that of PDL treatment after salicylic acid on psoriatic plaques. The other goal of this study was to compare the efficacy of the PDL treatment with that of clobetasol propionate treatment.

METHODS

Twenty-two patients with chronic, stable psoriatic plaques that involved less than 20% of their body were included in the study. Three similar-appearing psoriasis plaques in these patients were selected. Whereas the first plaque received only PDL, the second plaque received PDL after salicylic acid, and the third plaque received clobetasol propionate ointment and salicylic acid. Evaluation of the study plaques was carried out by the modified Psoriasis Area and Severity Index (mPASI) score and by measuring the area of the plaques.

RESULTS

Of the 21 patients, 19 completed the study. Although the decrease in mPASI scores was determined to be maximum for clobetasol propionate + salicylic acid-treated plaques and minimum for only PDL-treated plaques, the decrease was statistically significant in all groups when compared with baseline (p < .003). At the 3- and 6-week evaluations, there was a statistically significant difference between clobetasol propionate + salicylic acid-treated plaques and the two PDL-treated plaques (p < .003); however, the difference observed at the 9-, 12-, and 15-week evaluations was statistically significant only between clobetasol propionate + salicylic acid-treated plaques and PDL-treated plaques (p < .003). When the baseline and 15-week evaluations were compared, there was no statistically significant increase in the mean lesion areas of clobetasol propionate + salicylic acid-treated psoriatic plaques (p > .003), but there was a statistically significant increase in the mean lesion areas of two PDL-treated psoriatic plaques (p < .003).

CONCLUSION

The results of this study showed that the effect of PDL could be increased when salicylic acid was added to treatment, although there was no statistically significant difference between both treatment protocols. However, clobetasol propionate + salicylic acid treatment is more effective than both PDL and PDL + salicylic acid treatment.

Efficacy of the pulsed dye laser in the treatment of localized recalcitrant plaque psoriasis: a comparative study

BACKGROUND

Localized chronic plaque psoriasis, resistant to local therapy, may be very hard to treat. The treatment of these lesions with a pulsed dye laser (PDL) has been described before, but a comparative study between the PDL and a potent topical treatment has never been performed.

OBJECTIVES

To compare the efficacy of the PDL in the treatment of localized, recalcitrant plaque psoriasis with a potent topical therapy, using calcipotriol/betamethasone dipropionate (Dovobet) as an active comparator.

METHODS

Eight patients with psoriasis were treated with both PDL (585 nm) and calcipotriol/betamethasone dipropionate in an open, intrapatient, left-right comparison. A plaque severity score (sum score) and photographs were used to document the course of therapy. Patients reported pain on a visual analogue scale.

RESULTS

Both treatments were well tolerated, although one patient left the study due to post-PDL treatment pain. A significant difference in the sum score 12 weeks after treatment was seen in favour of the PDL (62% vs. 19% reduction; P<0.05). Scores for erythema declined significantly at week 12 in both the PDL and the calcipotriol/betamethasone dipropionate group (P<0.001). Induration and desquamation scores were significantly reduced at week 12 in the PDL group, without a statistically significant reduction in calcipotriol/betamethasone-treated lesions. The pain scores declined with progressive PDL treatments, although not statistically significantly.

CONCLUSIONS

PDL treatment might be considered for the treatment of localized, recalcitrant plaque psoriasis, when other topical therapies have failed.

Clinical and immunohistochemical evaluation of psoriatic plaques treated with topical 5-aminolaevulinic acid photodynamic therapy

BACKGROUND/PURPOSE

The aims of this study were to investigate the clinical and immunohistochemical events of psoriatic plaques during photodynamic therapy (PDT) using topical application of 5-aminolaevulinic acid (ALA).

METHODS

Twelve psoriatic patients were recruited for this study. Four of them dropped out because of pain during treatment. The effect of PDT was evaluated in the remaining eight. One plaque was selected in each patient and treated once weekly with PDT 10-30 J/cm(2) two to five times. It was evaluated by using the scale, erythema and induration (SEI) index (maximal score per patient=9). Pain during treatment was assessed by a visual analogue scale (VAS), ranging from 0 to 10. Skin biopsies were taken before treatment, after two treatments and after completion of treatment, and were evaluated by immunohistochemistry.

RESULTS

Median SEI scores were significantly reduced from 7 (range 5-9) before to 1.5 (range 0-3) following treatment (P<0.0001). The median pain during PDT was 7. The number of vessels in the subpapillary dermis, identified by antibodies against Factor VIII and endoglin, increased during and/or after treatment in six of eight patients. Before treatment, the epidermal growth factor (EGF) receptor was displayed throughout the epidermis, keratin 16 suprabasally, involucrin from the stratum granulosum to the lower spinous layers and filaggrin in stratum granulosum with focal absence. There was a moderate dermal infiltrate of CD4(+) cells and a sparse one of CD8(+). Following treatment, the EGF receptor was still displayed throughout the epidermis in seven of eight specimens. Cytokeratin 16 expression decreased markedly. Involucrin was not seen as deep in the spinous layers as before PDT. Filaggrin was expressed throughout the stratum granulosum and often weakly in the upper stratum spinosum. The number of CD4(+) and CD8(+) dermal cells decreased.

CONCLUSION

PDT improved psoriasis and induced dermal neovascularization. Although a good clinical response was seen in most of our patients, the high frequency of discomfort during treatment limits the usefulness of ALA-PDT for psoriasis. The mechanism of the neovascularization is unknown. It may be owing to an indirect effect of PDT on the microvasculature and immune system or recovery phenomena.

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

BACKGROUND AND OBJECTIVES

The excimer laser delivers high energy monochromatic ultraviolet (UV) B at 308 nm. Advantages over conventional UV sources include targeting of lesional skin, reducing cumulative dose and inducing faster clearance. Studies of the pulsed dye laser (PDL) in psoriasis report between 57% and 82% response rates; remission may extend to 15 months. To our knowledge, this is the first study assessing both excimer and PDL in psoriasis.

METHODS

We conducted a within-patient controlled prospective trial of treatment of localized plaque psoriasis. Twenty-two adult patients, mean Psoriasis Area and Severity Index 7.1, were recruited. Fifteen patients completed the full treatment, of which 13 were followed up to 1 year. Two selected plaques were treated with excimer twice weekly and V Beam PDL, pretreated with salicylic acid (SA), every 4 weeks, respectively. Two additional plaques, treated with SA alone or untreated, served as controls. The primary outcome measures were: (i) changes in plaque-modified Psoriasis Activity and Severity Index (PSI) scores from baseline to end of treatment; (ii) clinical response to treatment (CR(T)), assessed by serial photographs; (iii) percentage of plaques clear at the end of treatment; and (iv) percentage of plaques clear at 1-year follow-up. The secondary outcome measures were: (i) number of laser treatments to clearance; (ii) time to relapse; (iii) frequency of side-effects; and (iv) qualitative observations with SIAscope.

RESULTS

The mean improvement in PSI was 4.7 (SD 2.1) with excimer and 2.7 (SD 2.4) with PDL. PSI improvement was significantly greater in excimer than PDL (P = 0.003) or both control plaques (P < 0.001). CR(T) indicated 13 patients responded best with excimer, two patients best with PDL, and in seven patients there was no difference between the two lasers. CR(T) was significantly greater for excimer than PDL (P = 0.003) or both controls (P < 0.001). CR(T) was also significantly greater for PDL than SA alone (P = 0.004) or untreated control (P =0.002). Nine (41%) patients cleared with excimer, after mean 8.7, median 10 weeks treatment. Seven of these nine patients were followed up to 1 year; four remained clear, two relapsed at 1 month, and one at 6 months. Six (27%) patients cleared with PDL, after mean 3.3, median four treatments. All six patients were followed up to 1 year; four remained clear, one relapsed at 4 months and one at 9 months. Despite common side-effects including blistering and hyperpigmentation, patient satisfaction was high. Serial images obtained with the SIAscope during treatment indicated different mechanisms of action of the two lasers.

CONCLUSIONS

Excimer and V Beam PDL are useful treatments for plaque psoriasis. Although the excimer appears to be on average more efficacious, a subset of patients may respond better to PDL. Long-term remission is achievable with both lasers.

In vivo quantification of the structural abnormalities in psoriatic microvessels before and after pulsed dye laser treatment

BACKGROUND

Microvascular abnormalities (capillary elongation, widening and tortuosity) are a characteristic feature of psoriasis and form one of the pathological diagnostic criteria. These changes occur early in the progression of a psoriatic plaque, before there is clinical or histological evidence of epidermal hyperplasia. Treatment of psoriatic microvessels with a pulsed dye laser (PDL) has been associated with both clinical improvement and clearance of lesions.

OBJECTIVES

To quantify the structural vascular abnormalities in plaque skin using noninvasive techniques in vivo. Investigations were carried out before and after PDL treatment to determine the nature of laser-induced microvascular changes and the relationship between these changes and clinical improvement.

METHODS

Plaque microvessels were visualized using native capillaroscopy. Plaques were then treated three times with the PDL at 14-day intervals. Native capillaroscopy was repeated at 2 and 6 weeks after the final laser treatment. Images were analysed using a combination of nonstereological and stereological measurements.

RESULTS

Whole body disease was stable. Treated plaques showed a 48% reduction in plaque severity score (P < 0.01). Native studies showed that the PDL significantly reduced plaque microvessel density (P < 0.05), image area fraction (P < 0.01), microvessel length density (P < 0.01) and vessel image width (P < 0.01). The reduction in plaque severity score (which denoted clinical improvement) was related quantitatively to the reduction in microvessel area per unit area of plaque skin, i.e. the image area fraction (correlation coefficient = 0.772, P < 0.01). The greatest response of plaque microvessels was within 2 weeks after the final laser treatment, while the greatest reduction in plaque severity score occurred between 2 and 6 weeks after the final laser treatment, i.e. clinical improvement was preceded by microvascular improvement.

CONCLUSIONS

These findings indicate that there is a close correlation between the state of the superficial vasculature and the clinical status of psoriasis. The expanded superficial microvascular bed in plaque skin is a necessary component for maintaining clinical lesions and these blood vessels are thus a legitimate target for treatment.

Blood flow in psoriatic plaques before and after selective treatment of the superficial capillaries

BACKGROUND

Blood flow is substantially raised in psoriatic plaques. In addition, mechanisms of vasoconstriction and vasodilatation (locally and neurally mediated), although intact, are altered in magnitude. The elevated blood flow is considered to be a result of abnormalities (increase in vessel number, width and length) in the superficial capillary loops rather than changes in the deeper feeding vessels (arterioles).

OBJECTIVES

To determine if selective thermolysis of psoriatic capillaries with a pulsed dye laser (PDL) leads to normalization of blood flow and also if the vasoconstrictor and vasodilator responses are returned to normal magnitude.

METHODS

Laser Doppler red cell flux was recorded from plaques on the forearm or elbow (untreated plaque site) and from clinically uninvolved skin at an equivalent site on the opposite limb. Plaques were treated on three occasions, at 2-weekly intervals, with a PDL. Laser Doppler red cell flux measurements were then repeated, 2 weeks after the final laser treatment was performed (treated plaque site).

RESULTS

There was significant clinical improvement in plaques after treatment (P = 0.02), but complete clearance of lesions did not occur. Blood flow in plaques under basal conditions remained significantly elevated above blood flow in clinically uninvolved skin, despite laser treatment (P < 0.001). The physiological tests of resistance vessel function showed that the laser did not impair the ability of psoriatic resistance vessels to constrict and dilate. However, there was only partial resolution of the percentage responses to the provocation tests towards the values recorded in clinically uninvolved skin.

CONCLUSIONS

The results indicate that it is unlikely that the reduced resistance of the expanded superficial capillary bed is solely responsible for the massively elevated blood flow in plaque skin. It is more likely that the vascular abnormalities in psoriasis also extend to involve the deeper, larger resistance vessels (arterioles).

Laser and novel light source treatments for psoriasis

BACKGROUND AND OBJECTIVES

There are many treatment modalities for psoriasis including topical therapy, ultraviolet light therapy, systemic agents, and more recently the advent of the biologic agents.

STUDY DESIGN/MATERIALS AND METHODS

In addition, selective treatment using lasers and light sources that target the individual psoriatic plaques have also been employed.

RESULTS/CONCLUSION

This article will highlight and review the employment of laser-assisted devices in the treatment of plaque psoriasis.

Comparison of the microvasculature of basal cell carcinoma and actinic keratosis using intravital microscopy and immunohistochemistry

BACKGROUND

Angiogenesis is a prerequisite for growth of invasive tumours. We hypothesized that angiogenesis would be present in invasive basal cell carcinoma (BCC) but not in a noninvasive tumour such as actinic keratosis (AK).

OBJECTIVES

To investigate both types of tumour for evidence of angiogenesis.

METHODS

Patients with BCC or AK underwent intravital videocapillaroscopy. Three regions were examined: the tumour, perilesional skin and a control site. Microvessel width, area fraction and length density were determined from capillaroscopy images. Biopsies were stained for CD34 and a microvessel count was performed.

RESULTS

Capillaroscopy demonstrated a grossly disorganized tumour microcirculation in BCC. Compared with control skin, microvessel width was increased 2.4-fold, area fraction was increased 4.9-fold and length density was increased 5.9-fold. In AK, microvessel width was increased 1.7-fold, area fraction 2.5-fold and length density 3.4-fold. Vessel width and area fraction were significantly greater in BCC than AK. Biopsies showed significant increases in microvessel length density for both BCC and AK compared with control skin, with BCC significantly greater than AK.

CONCLUSIONS

Angiogenesis was demonstrated in BCC in humans in vivo, and to a lesser extent in AK.

[Psoriasis vulgaris. An indication for lasers?]

Treatment of psoriasis is often complicated and remains a challenge. Along with the many new immunomodulatory approaches, various laser systems have been employed in an attempt to treat chronic plaque psoriasis. These include CO(2), Er:YAG, pulsed dye, 1302 nm Nd:YAG and excimer lasers. After reviewing and critically evaluating the literature, we conclude that the 308 nm excimer laser has proven its efficacy, not only in comparison with other laser systems, but also when compared with conventional 311 nm narrow-band UVB treatment. It is an efficient and promising therapeutic option for treating different forms of psoriasis.

The Children's Dermatology Life Quality Index: validation of the cartoon version

BACKGROUND

In 1995 the Children's Dermatology Life Quality Index (CDLQI) was developed as a tool to allow quality of life assessment of children with skin conditions. This initial questionnaire was in a written format.

OBJECTIVES

Using the same validated questions, a full-colour cartoon version has been developed. The aim of this study was to validate this against the initial written questionnaire in a three-part study.

METHODS

The first part of the study piloted the use of both versions in an outpatient setting. One hundred and one children completed both versions of the CDLQI in a random order. A further 66 children completed the cartoon CDLQI in outpatients, and subsequently completed the cartoon version on the same day at home, which was returned by post. The scores were compared. In the second part, in more controlled conditions to eliminate parental and investigator bias, 107 children with current dermatological problems were administered both versions of the CDLQI in a random order. The scores were analysed, and time to complete each version, and the child and parental preferences, were recorded. The third part assessed compliance by asking 546 children recently reviewed in dermatology clinics to return a single completed postal CDLQI. Half of the children were given the text, and half the cartoon version.

RESULTS

The median age of participating children was 11 years. There was no significant difference in scores between the two versions in both parts 1 and 2, but the cartoon version was completed faster (median 90 s) than the written version (median 120 s) (P < 0.0001). Both children and their parents significantly preferred the cartoon version and found it easier to use. Forty-six per cent of the postal CDLQI questionnaires were returned; there was no difference in compliance between the two versions.

CONCLUSIONS

The cartoon CDLQI is equivalent to the previously validated written CDLQI version, but is faster and easier for children to use, and is preferred by both children and parents.