PUVA, UVB, psoriasis, and nonmelanoma skin cancer

Efficacy and safety of tofacitinib for chronic plaque psoriasis and psoriatic arthritis: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

To summarize and analyze the results of published randomized controlled trials of tofacitinib for the treatment of chronic plaque psoriasis and psoriatic arthritis(PsA) and discuss its efficacy and safety.

PATIENTS AND METHODS

An exhaustive systematic search encompassing PubMed, Cochrane, Embase, and Web of Science databases was conducted up to July 2023. Studies eligible for inclusion were analyzed, organized using Review Manager version 5.4.1 (Cochrane Collaboration, Oxford, UK) and STATA 15.0 version (Stata Corp, College Station, TX, USA) software.

RESULTS

A total of six articles, covering 1393 patients (844 treated with tofacitinib and 549 with placebo), were included. The foundational characteristics of tofacitinib and placebo group showed similarity, except for age and Dermatology Life Quality Index (DLQI) score, especially in the context of chronic plaque psoriasis. It is noteworthy that we discovered tofacitinib exhibited a significant impact on Psoriasis Area and Severity Index 75 (PASI75) response, Physician's Global Assessment (PGA) response, and adverse events (AEs) in cases of chronic plaque psoriasis. Similarly, tofacitinib demonstrated substantial influence on American College of Rheumatology 20/50 (ACR20/50) response, PASI75 response, as well as alterations in Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) Score, Health Assessment Questionnaire-Disability Index (HAQ-DI) Score, Dactylitis Severity Score (DSS), and Leeds Enthesitis Index (LEI) Score in the context of psoriatic arthritis (PsA). Nevertheless, there was no statistically significant impact of tofacitinib on serious adverse events (SAEs) in chronic plaque psoriasis, as well as on both adverse events (AEs) and SAEs in psoriatic arthritis (PsA).

CONCLUSIONS

A comprehensive analysis revealed that tofacitinib has a positive effect on addressing skin and joint symptoms, as well as improving the quality of life for patients with chronic plaque psoriasis and psoriatic arthritis (PsA). However, the safety of the drug's long-term usage even requires further validation. Key Points • In 6 analyses involving a total of 1393 patients, tofacitinib exhibits positive effect on the treatment of both chronic plaque psoriasis and psoriatic arthritis (PsA). • Although dose-based subgroup analyses have demonstrated effectiveness. Some studies indicate that the 5-mg dose (twice daily) may not show an effect due to the failure of non-inferiority trials comparing tofacitinib with placebo. Therefore, caution is required when interpreting its effectiveness. On the other hand, the 10-mg dose (BID) has been associated with an increase in adverse events and serious adverse events, and is recommended to be used with caution in patients with cardiovascular or uveitis risk factors. • Tofacitinib has efficacy in comorbid psychiatric disorders (depression, anxiety, or Alzheimer's disease) and inflammatory bowel disease (ulcerative colitis), but patients with comorbid renal insufficiency, hepatic dysfunction, osteoporosis, cardiovascular disease, or uveitis may need to be moderated or avoided with tofacitinib.

Immune cells in the epithelial immune microenvironment of psoriasis: emerging therapeutic targets

Psoriasis is a chronic autoimmune inflammatory disease characterized by erroneous metabolism of keratinocytes. The development of psoriasis is closely related to abnormal activation and disorders of the immune system. Dysregulated skin protective mechanisms can activate inflammatory pathways within the epithelial immune microenvironment (EIME), leading to the development of autoimmune-related and inflammatory skin diseases. In this review, we initially emphasized the pathogenesis of psoriasis, paying particular attention to the interactions between the abnormal activation of immune cells and the production of cytokines in psoriasis. Subsequently, we delved into the significance of the interactions between EIME and immune cells in the emergence of psoriasis. A thorough understanding of these immune processes is crucial to the development of targeted therapies for psoriasis. Finally, we discussed the potential novel targeted therapies aimed at modulating the EIME in psoriasis. This comprehensive examination sheds light on the intricate underlying immune mechanisms and provides insights into potential therapeutic avenues of immune-mediated inflammatory diseases.

Efficacy and safety of tofacitinib for the treatment of chronic plaque psoriasis: a systematic review and meta-analysis

Background

Tofacitinib is an oral Janus kinase (JAK) inhibitor that targets JAK1 and JAK3, and thus regulates immune response. Therefore, tofacitinib is used to treat immune-mediated inflammatory diseases such as chronic plaque psoriasis. The objective of this study was to systematically assess the efficacy and safety of tofacitinib in treating chronic plaque psoriasis.

Objective

To systematically review the efficacy and safety of tofacitinib in the treatment of chronic plaque psoriasis, we performed a meta-analysis to evaluate the efficacy and safety of tofacitinib in patients with chronic plaque psoriasis.

Methods

Databases including PubMed, Embase, and The Cochrane Library were searched for randomized controlled trials about the efficacy and safety of tofacitinib in treating chronic plaque psoriasis from inception to August 2017 (PROSPERO Code No: CRD42017076587).

Results

Six articles (seven randomized controlled trial studies) involving 3743 patients were included. The meta-analysis results showed that for efficacy, tofacitinib (5 mg or 10 mg) compared with placebo can significantly improve the Physician’s Global Assessment response, PASI75, and PASI90 after treatment. For safety, the incidence of adverse reactions was statistically significantly higher for tofacitinib compared with placebo.

Conclusion

Treatment of chronic plaque psoriasis with tofacitinib is effective, but there may be more adverse reactions.

Risk of skin cancer in psoriasis patients receiving long-term narrowband ultraviolet phototherapy: Results from a Taiwanese population-based cohort study

BACKGROUND

Narrowband ultraviolet B (NB-UVB) phototherapy is a widely used treatment for various dermatoses. The risk of skin cancer following long-term NB-UVB phototherapy has rarely been explored in skin phototypes III-V.

METHODS

We conducted a nationwide-matched cohort study and identified a total of 22 891 psoriasis patients starting NB-UVB phototherapy from the Taiwan National Health Insurance Database during the period 2000-2013. Cumulative incidences of skin cancers were compared between subjects receiving less than 90 UVB treatments (S-cohort, N = 13 260) and age- as well as propensity score-matched subjects receiving more than or equal to 90 UVB treatments (L-cohort, N = 3315).

RESULTS

There were no significant differences in the overall cumulative incidences of skin cancers between the two cohorts (log-rank t test, P = 0.691) during the follow-up periods. The S-cohort had a significantly lower prevalence of actinic keratosis when compared with the L-cohort (0.54% vs 1.00%, P = 0.005).

CONCLUSION

Long-term NB-UVB phototherapy does not increase skin cancer risk compared with short-term NB-UVB phototherapy in psoriasis patients with skin phototypes III-V.

Multiple Keratoacanthomas Arising Post-UVB Therapy

Background:

Ultraviolet (UV) radiation is known to be an important etiologic agent in the development of skin cancer. Keratoacanthoma is an unusual, well-described cutaneous neoplasm that resembes squamous cell carcinoma but spontaneously resolves. Rarely, multiple keratoacanthomas may develop. Objective We present a case of multiple keratoacanthomas in a patient with psoriasis who had received UVB phototherapy. These lesions were hyperkeratotic papules, many of which spontaneously resolved and demonstrated the histologic characteristics of keratoacanthoma.

Conclusion:

We believe that UV radiation is the most likely etiologic factor in this patient's development of multiple keratoacanthomas. We wish to bring to the attention of clinicians this unusual adverse effect of UV treatment.

Oral tofacitinib efficacy, safety and tolerability in Japanese patients with moderate to severe plaque psoriasis and psoriatic arthritis: A randomized, double-blind, phase 3 study

Tofacitinib is an oral Janus kinase inhibitor that is being investigated for psoriasis and psoriatic arthritis. Japanese patients aged 20 years or more with moderate to severe plaque psoriasis and/or psoriatic arthritis were double‐blindly randomized 1:1 to tofacitinib 5 or 10 mg b.i.d. for 16 weeks, open‐label 10 mg b.i.d. for 4 weeks, then variable 5 or 10 mg b.i.d. to Week 52. Primary end‐points at Week 16 were the proportion of patients achieving at least a 75% reduction in Psoriasis Area and Severity Index (PASI75) and Physician's Global Assessment of “clear” or “almost clear” (PGA response) for psoriasis, and 20% or more improvement in American College of Rheumatology criteria (ACR20) for patients with psoriatic arthritis. Safety was assessed throughout. Eighty‐seven patients met eligibility criteria for moderate to severe plaque psoriasis (5 mg b.i.d., n = 43; 10 mg b.i.d., n = 44), 12 met eligibility criteria for psoriatic arthritis (5 mg b.i.d., n = 4; 10 mg b.i.d., n = 8) including five who met both criteria (10 mg b.i.d.). At Week 16, 62.8% and 72.7% of patients achieved PASI75 with tofacitinib 5 and 10 mg b.i.d., respectively; 67.4% and 68.2% achieved PGA responses; all patients with psoriatic arthritis achieved ACR20. Responses were maintained through Week 52. Adverse events occurred in 83% of patients through Week 52, including four (4.3%) serious adverse events and three (3.2%) serious infections (all herpes zoster). No malignancies, cardiovascular events or deaths occurred. Tofacitinib (both doses) demonstrated efficacy in patients with moderate to severe plaque psoriasis and/or psoriatic arthritis through 52 weeks; safety findings were generally consistent with prior studies.

Tofacitinib versus etanercept or placebo in moderate-to-severe chronic plaque psoriasis: a phase 3 randomised non-inferiority trial

BACKGROUND

New therapeutic options are needed for patients with psoriasis. Tofacitinib, an oral Janus kinase inhibitor, is being investigated as a treatment for moderate-to-severe chronic plaque psoriasis. In this study, we aimed to compare two tofacitinib doses with high-dose etanercept or placebo in this patient population.

METHODS

In this phase 3, randomised, multicentre, double-dummy, placebo-controlled, 12-week, non-inferiority trial, adult patients with chronic stable plaque psoriasis (for ≥12 months) who were candidates for systemic or phototherapy and had a Psoriasis Area and Severity Index (PASI) score of 12 or higher and a Physician's Global Assessment (PGA) of moderate or severe, and had failed to respond to, had a contraindication to, or were intolerant to at least one conventional systemic therapy, were enrolled from 122 investigational dermatology centres worldwide. Eligible patients were randomly assigned in a 3:3:3:1 ratio to receive tofacitinib 5 mg or 10 mg twice daily at about 12 h intervals, etanercept 50 mg subcutaneously twice weekly at about 3-4 day intervals, or placebo. Randomisation was done by a computer-generated randomisation schedule, and all patients and study personnel were masked to treatment assignment. The co-primary endpoints were the proportion of patients at week 12 with at least a 75% reduction in the PASI score from baseline (PASI75 response) and the proportion of patients achieving a PGA score of "clear" or "almost clear" (PGA response), analysed in the full analysis set (all patients who were randomised and received at least one dose of study drug). This study is registered with ClinicalTrials.gov, number NCT01241591.

FINDINGS

Between Nov 29, 2010, and Sept 13, 2012, we enrolled 1106 eligible adult patients with chronic plaque psoriasis and randomly assigned them to the four treatment groups (330 to tofacitinib 5 mg twice daily, 332 to tofacitinib 10 mg twice daily, 336 to etanercept 50 mg twice weekly, and 108 to placebo). Of these patients, 1101 actually received their assigned study medication (329 in the tofactinib 5 mg group, 330 in the tofacitinib 10 mg group, 335 in the etanercept group, and 107 in the placebo group). At week 12, PASI75 responses were recorded in 130 (39·5%) of 329 patients in the tofacitinib 5 mg group, 210 (63·6%) of 330 in the tofacitinib 10 mg group, 197 (58·8%) of 335 in the etanercept group, and six (5·6%) of 107 in the placebo group. A PGA response was achieved by 155 (47·1%) of 329 patients in the tofacitinib 5 mg group, 225 (68·2%) of 330 in the tofacitinib 10 mg group, 222 (66·3%) of 335 in the etanercept group, and 16 (15·0%) of 107 in the placebo group. The rate of adverse events was similar across the four groups, with serious adverse events occurring in seven (2%) of 329 patients in the tofacitinib 5 mg group, five (2%) of 330 in the tofacitinib 10 mg group, seven (2%) of 335 in the etanercept group, and two (2%) of 107 in the placebo group. Three (1%) of 329 patients in the tofacitinib 5 mg group, ten (3%) of 330 in the tofacitinib 10 mg group, 11 (3%) of 335 in the etanercept group, and four (4%) of 107 patients in the placebo group discontinued their assigned treatment because of adverse events.

INTERPRETATION

In patients with moderate-to-severe plaque psoriasis, the 10 mg twice daily dose of tofacitinib was non-inferior to etanercept 50 mg twice weekly and was superior to placebo, but the 5 mg twice daily dose did not show non-inferiority to etanercept 50 mg twice weekly. The adverse event rates over 12 weeks were similar for tofacitinib and etanercept. This study indicates that in the future tofacitinib could provide a convenient and well-tolerated therapeutic option for patients with moderate-to-severe plaque psoriasis.

FUNDING

Pfizer Inc.

Whole-genome sequencing reveals oncogenic mutations in mycosis fungoides

The pathogenesis of mycosis fungoides (MF), the most common cutaneous T-cell lymphoma (CTCL), is unknown. Although genetic alterations have been identified, none are considered consistently causative in MF. To identify potential drivers of MF, we performed whole-genome sequencing of MF tumors and matched normal skin. Targeted ultra-deep sequencing of MF samples and exome sequencing of CTCL cell lines were also performed. Multiple mutations were identified that affected the same pathways, including epigenetic, cell-fate regulation, and cytokine signaling, in MF tumors and CTCL cell lines. Specifically, interleukin-2 signaling pathway mutations, including activating Janus kinase 3 (JAK3) mutations, were detected. Treatment with a JAK3 inhibitor significantly reduced CTCL cell survival. Additionally, the mutation data identified 2 other potential contributing factors to MF, ultraviolet light, and a polymorphism in the tumor suppressor p53 (TP53). Therefore, genetic alterations in specific pathways in MF were identified that may be viable, effective new targets for treatment.

Comparison of clinical effects of psoriasis treatment regimens among calcipotriol alone, narrowband ultraviolet B phototherapy alone, combination of calcipotriol and narrowband ultraviolet B phototherapy once a week, and combination of calcipotriol and narrowband ultraviolet B phototherapy more than twice a week

We compared the clinical efficacy of various psoriasis treatments among: (i) topical application of calcipotriol ointment twice daily (group I); (ii) topical application of calcipotriol ointment twice daily and narrowband ultraviolet B NB-UVB phototherapy once a week (group II); (iii) topical application of heparinoid ointment twice daily and NB-UVB phototherapy more than twice a week (group III); and (iv) topical application of calcipotriol ointment twice daily and NB-UVB phototherapy more than twice a week (group IV). Ten patients were randomly selected for each group and treated by the indicated regimens for 12 weeks. All treatments were effective and significantly improved Psoriasis Area and Severity Index (PASI) scores, self-administered PASI scores and visual analog scale scores of pruritus. Group IV showed most marked and rapid reduction in PASI and self-PASI scores among the four regimens. Although the serum levels of interleukin (IL)-17, IL-20 and IL-22 and psoriasis disability index were significantly decreased after the treatments, no significant difference was detected among the four groups. Our study indicates that combination of calcipotriol ointment plus NB-UVB more than twice a week is superior to other treatment regimens, rapidly improving psoriasis lesions.

The contribution of medical physics to the development of psoralen photochemotherapy (PUVA) in the UK: a personal reminiscence

Psoralen photochemotherapy (PUVA) is the combined treatment of skin disorders with a photosensitizing drug (Psoralen) and UltraViolet A radiation. The introduction of PUVA therapy has arguably been the most important development in dermatology over the past 30 years and from the first days of the treatment being introduced in the UK, British medical physicists were an integral part of the effort to establish it. Medical physicists have contributed to this development in a number of ways, from designing irradiation units in the early days of the technique, through to collaborating with dermatologists in prosecuting clinical and experimental studies aimed at improving patient outcomes. That the dose of UVA radiation is administered quantitatively, and not qualitatively, has probably been the single most important contribution made by several medical physicists over this period. However, despite concerns that were expressed almost 30 years ago about the accuracy with which UVA doses are administered to patients, the medical physics community still has some way to go before we can be satisfied that statements about UVA irradiance and dose can be made with confidence.

Quality of life in psoriasis improves after standardized administration of narrowband UVB phototherapy

SUMMARY Psoriasis is a chronic fluctuating dermatosis with demonstrable impact on patients' quality of life. Our aim was to investigate if narrowband UVB phototherapy administered to psoriatic patients in a standardized manner leads to an improvement in patients' perceived quality of life. A total of 138 patients with psoriasis were recruited from referrals to the Skin and Cancer Foundation, Australia between January 1998 and September 2002. Patients had psoriasis inadequately controlled by topical therapies alone and no contraindications to the use of phototherapy. Patients completed a pre- and post-therapy questionnaire on quality of life parameters. The differences in mean and standard deviation of quality of life parameters were measured using a paired sample t-test based on pre- and post-phototherapy questionnaires. Ninety patients were included in the study. Forty-eight patients were excluded as they had not completed post-phototherapy questionnaires. The course of narrowband UVB phototherapy was found to significantly improve quality of life in psoriasis patients (P <or= 0.005). We conclude that narrowband UVB phototherapy improves quality of life in patients with psoriasis.

Skin cancer and immunosuppression

All immunosuppressive treatments, either pharmacological or physical, have the potential to impair the skin immune system network of cells and cytokines, thus leading to an increased incidence of skin cancer. Since skin cancer in transplant recipients may show uncommon clinical features and have an unusually aggressive course, transplant patients should be strictly followed up by experienced dermatologists in order to diagnose and treat properly any skin cancer in an early phase. Importantly, due to the fact that sun exposure increases immunosuppression in the skin, patients should be clearly informed about the additional risk of sun exposure and the preventive measures to be taken.

UVB phototherapy and skin cancer risk: a review of the literature

BACKGROUND

UVB phototherapy is a common treatment modality for psoriasis and other skin diseases. Although UVB has been in use for many decades, many clinicians are hesitant to use this type of phototherapy because of concern over increasing the skin cancer risk. Over the past 20 years, numerous studies have been published examining this issue, but a consensus or analysis of the skin cancer risk is required for the dermatologist to make an educated risk-benefit analysis.

OBJECTIVE

To assess the risk of skin cancer associated with UVB phototherapy.

METHODS

All prospective or retrospective studies were identified in MEDLINE from 1966 to June 2002. Bibliographies were searched to identify any additional studies examining this issue. All studies that attempted to quantify or qualify any additional skin cancer risk from UVB phototherapy were included. Study selection was performed by two independent reviewers.

RESULTS

Eleven studies (10 of which concerned psoriasis patients), involving approximately 3400 participants, were included. Of note, three of the studies involved the same cohort: members of the 16-center US Psoralen plus UVA (PUVA) Follow-up Study: Other than the most recent Finnish study, all studies eventually showed no increased skin cancer risk with UVB phototherapy. One of the PUVA cohort studies examined genital skin cancers, and found an increased rate of genital tumors associated with UVB phototherapy, although this study has not been duplicated.

CONCLUSION

The evidence suggests that UVB phototherapy remains a very safe treatment modality.

Traditional therapies in the management of moderate to severe chronic plaque psoriasis: an assessment of the benefits and risks

Psoriasis is a chronic, recurrent disease that affects between 1% and 3% of the population. Patients with moderate to severe disease generally require phototherapy (e.g. narrowband ultraviolet B radiation), photochemotherapy (oral psoralen plus ultraviolet A radiation) or systemic agents (e.g. ciclosporin, methotrexate, oral retinoids, fumaric acid esters) to control their disease adequately. In general, these therapeutic modalities have proven to be highly effective in the treatment of psoriasis. However, potentially serious toxicities can limit their long-term use. Given that there is no standard therapeutic approach for patients with moderate to severe psoriasis, the benefits and risks of phototherapy, photochemotherapy and systemic therapy must be weighed carefully for each patient, and treatment individualized accordingly. This review summarizes the benefits and risks of traditional, nonbiological therapies for moderate to severe chronic plaque psoriasis.

High levels of ultraviolet B exposure increase the risk of non-melanoma skin cancer in psoralen and ultraviolet A-treated patients

Sunlight and psoralen and ultraviolet A (PUVA) are risk factors for the development of squamous cell carcinoma (SCC) and, to a lesser extent, basal cell carcinoma (BCC). Ultraviolet B (UVB) therapy, used for the treatment of psoriasis, might also increase the risk of these tumors. We studied the relation of skin cancer incidence to UVB use among 1380 adult subjects enrolled in a long-term safety trial of PUVA therapy. We used negative binomial regression models to quantify the association between UVB and the development of non-melanoma skin cancer (NMSC), controlling for known confounders. High UVB exposure (> or =300 treatments vs <300 treatments) was associated with a modest but significant increase in SCC (adjusted incidence rate ratio (IRR)=1.37, 95% confidence interval (CI)=1.03-1.83) and BCC (adjusted IRR=1.45, 95% CI=1.07-1.96) risk. Among patients with <100 PUVA treatments, high UVB exposure was significantly associated with the development of SCC (adjusted IRR=2.75, 95% CI=1.11-6.84) and BCC (adjusted IRR=3.00, 95% CI=1.30-6.91) on body sites typically exposed to UVB therapy but not on chronically sun-exposed sites typically covered during therapy. For adults with high UVB exposure levels, UVB confers a modest increase in NMSC risk, much less than that observed with PUVA. Therefore, UVB remains a relatively low-risk treatment for psoriasis.

Multiple Keratoacanthomas Arising Post-UVB Therapy

BACKGROUND

Ultraviolet (UV) radiation is known to be an important etiologic agent in the development of skin cancer. Keratoacanthoma is an unusual, well-described cutaneous neoplasm that resembles squamous cell carcinoma but spontaneously resolves. Rarely, multiple keratoacanthomas may develop.

OBJECTIVE

We present a case of multiple keratoacanthomas in a patient with psoriasis who had received UVB phototherapy. These lesions were hyperkeratotic papules, many of which spontaneously resolved and demonstrated the histologic characteristics of keratoacanthoma.

CONCLUSION

We believe that UV radiation is the most likely etiologic factor in this patient's development of multiple keratoacanthomas. We wish to bring to the attention of clinicians this unusual adverse effect of UV treatment.

Iatrogenic skin cancer: induction by psoralen/ultraviolet A and immunosuppression of organ transplant recipients

Photochemotherapy (psoralen/UVA (PUVA)) is an efficient therapeutic tool for a wide range of skin diseases. Concern, however, exists regarding the long-term carcinogenic effects of this treatment modality and, as a consequence, is being used less frequently. PUVA remains an important treatment in our therapeutic armamentarium but must be used with caution in those patients with risk factors and cumulative dose exposure must be limited. PUVA-induced cancers show features in common with skin cancers induced by immunosuppressed organ transplant recipients. Tumours in the latter group of individuals are, however, much more aggressive and difficult to manage.

Toxic effects of ultraviolet radiation on the skin

Ultraviolet (UV) irradiation present in sunlight is an environmental human carcinogen. The toxic effects of UV from natural sunlight and therapeutic artificial lamps are a major concern for human health. The major acute effects of UV irradiation on normal human skin comprise sunburn inflammation (erythema), tanning, and local or systemic immunosuppression. At the molecular level, UV irradiation causes DNA damage such as cyclobutane pyrimidine dimers and (6-4) photoproducts, which are usually repaired by nucleotide excision repair (NER). Chronic exposure to UV irradiation leads to photoaging, immunosuppression, and ultimately photocarcinogenesis. Photocarcinogenesis involves the accumulation of genetic changes, as well as immune system modulation, and ultimately leads to the development of skin cancers. In the clinic, artificial lamps emitting UVB (280-320 nm) and UVA (320-400 nm) radiation in combination with chemical drugs are used in the therapy of many skin diseases including psoriasis and vitiligo. Although such therapy is beneficial, it is accompanied with undesirable side effects. Thus, UV radiation is like two sides of the same coin--on one side, it has detrimental effects, and on the other side, it has beneficial effects.

Vitiligo. Pathogenesis and treatment

Vitiligo is an acquired skin disorder caused by the disappearance of pigment cells from the epidermis that gives rise to well defined white patches which are often symmetrically distributed. The lack of melanin pigment makes the lesional skin more sensitive to sunburn. Vitiligo can be cosmetically disfiguring and it is a stigmatizing condition, leading to serious psychologic problems in daily life. It occurs worldwide in about 0.5% of the population and it occurs as frequently in males as it does in females. The cause is unknown, but might involve genetic factors, autoimmunity, neurologic factors, toxic metabolites, and lack of melanocyte growth factors. Since a causative (gene) treatment is not (yet) available, current modalities are directed towards stopping progression and to achieving repigmentation in order to repair the morphology and functional deficiencies of the depigmented skin areas. Many treatments have been used for some time; however; there are some new developments: narrowband ultraviolet (UV) B (311 nm) therapy, the combination of corticosteroid cream + UVA therapy, and the transplantation of autologous pigment cells in various modalities. In widespread vitiligo, residual pigment can be removed by depigmentation agents. Sunscreens, camouflage products, and good guidance may help the patient cope better with the disease.

The role of PUVA in the treatment of psoriasis. Photobiology issues related to skin cancer incidence

Photochemotherapy with methoxsalen (8-methoxypsoralen) and long wavelength ultraviolet (UV) radiation (referred to as 'PUVA' for psoralen plus UVA) is commonly used to treat psoriasis and vitiligo. These vastly different diseases respond to the therapy by different mechanisms even though the immediate effects of the therapy--the photomodification of cellular biomolecules--is the same for each. Because psoriasis is not cured by PUVA, patients receive many treatments over their lifetime and have a significantly increased risk for the development of skin cancers (primarily squamous cell carcinomas). In this article the basic aspects of psoralen photobiology are reviewed briefly. Several recent studies describing the incidence of skin cancer in UVA treated psoriasis cohorts are comparatively reviewed. In addition the impact of the analysis of mutations in the tumor suppressor gene, p53, are summarized. An unexpected mutation spectrum (very few PUVA type T-->A transversions and frequent UVB solar signature C-->T transitions) suggest that effects other than direct DNA photoadduct formation may be at play. These analyses suggest that it may be possible to improve the therapeutic efficacy of PUVA by a careful evaluation of the mode of delivery. In this review the science behind PUVA is summarized. In addition, the incidence of skin cancer as a long term consequence of repeated treatments is surveyed. To relate clinical observations to molecular events, the nature of p53 mutations found in skin cancers from psoriasis patients is also analyzed. Finally some suggestions for improving the delivery of PUVA therapy are presented.

Malignant tumours and psoriasis: climatotherapy at the Dead Sea

In this retrospective, nation-wide cohort study, the risk of cancer was assessed for 1738 Danish patients with psoriasis subjected to climatotherapy at the Dead Sea during 1972-93, by linkage to the Danish Cancer Registry. The overall risk of cancer in patients treated at the Dead Sea (standardized incidence ratio, SIR = 1.59) was higher than that expected in the general population, owing to an excess risk of non-melanoma skin cancer (NMSC) [SIR = 4.2 for basal cell carcinoma (BCC) and 10.7 for squamous cell carcinoma (SCC)]. In addition, the distribution of NMSC among body sites, age groups and sexes was unusual in those treated at the Dead Sea, favouring NMSC in young individuals and at multiple sites (SIR = 10.7 for BCC and 57.2 for SCC), multiple BCCs being particularly common among young women. Thus, people subjected to climatotherapy at the Dead Sea for psoriasis constitute a high-risk group for NMSC, SCC in particular, but not for malignant diseases in general. The study design precludes conclusions on whether climatotherapy plays a specific part in skin carcinogenesis which is different from other sources of ultraviolet (UV) radiation, as climatotherapy is inevitably confounded by excess UV exposure.

Management of vitiligo. Results of a questionnaire among dermatologists in The Netherlands

BACKGROUND

Several therapeutic options are available for the treatment of vitiligo. Concern exists that there is no uniform approach towards the management of vitiligo among Dutch dermatologists.

METHODS

A written survey concerning the management of vitiligo was sent to 332 dermatologists in The Netherlands.

RESULTS

The response rate was 86%. "Giving information and reassurance concerning the nature of disease" was regarded by most dermatologists (68%) as being the most important goal in the management of vitiligo. Only 16% of the dermatologists aimed for active treatment in vitiligo. The reported therapy choices in children resembled those of adults, except that slightly more dermatologists did not prescribe active therapy in children. Nine different therapeutic modalities were mentioned as first choice therapies. Topical corticosteroids were indicated by most dermatologists as first choice therapy (241 out of 266, i.e. 91%); however, only 2% indicated that 50% or more of the patients achieved a successful treatment; 66% found that less than 25% of the patients were successfully treated with topical corticosteroids. Only 15% of the respondents reported that 50% or more of the patients were treated successfully with narrow-band UVB. The observed response profile to broad-band UVB therapy was found to be comparable with that of narrow-band UVB. The classical therapy with oral psoralen plus UVA (PUVA) was prescribed as first choice therapy by only 12% (32 out of 266) of the dermatologists. Only 6% of these respondents observed that 50% or more of the patients achieved successful therapy using oral PUVA. The recommended maximum treatment duration for topical corticosteroids, oral PUVA, and UVB therapy was found to vary from 3 to 12 months.

CONCLUSIONS

Most dermatologists in The Netherlands do not offer active treatment in vitiligo, probably because the estimated effectiveness of (nonsurgical) repigmentation therapy is low. In cases where treatment is prescribed, there appears to be no consensus on the choice of therapies and treatment strategies. The development of practice guidelines may be helpful in reducing inappropriate care and improving treatment outcome.

Current consensus and update on psoriasis therapy: a perspective from the U.S

Psoriasis is one of the more common forms of chronic dermatitis in the world. The latest U.S.-wide epidemiological study conducted by the author revealed a prevalence rate of 2.6% of the population, which translates to over 6 million Americans (1). Psoriasis comes in many different degrees of severity and responsiveness to treatment modalities. Some cases are very mild and quite responsive to treatment, while others are so severe, chronic and recalcitrant that they test the skill and ingenuity of the best clinicians. Fortunately, there are also many different treatment options. Topical therapies include crude coal tar, anthralin, corticosteroids, calcipotriol, and tazarotene. Phototherapy may be a better choice in patients with more extensive psoriasis; UVB or psoralen plus subsequest UVA (PUVA) can be used. There are also a host of systemic therapies (cyclosporine, methotrexate, acitretin), which can be chosen in recalcitrant cases, or when topical or phototherapy is impractical. Importantly, significant increases in efficacy can be obtained by combining multiple therapies (Re-PUVA, topical calcipotriol plus topical halobetasol) and significant decreases in side effects can be obtained by transitioning through or rotating between therapies (cyclosporine transitioning into acitretin).

Ultraviolet B irradiation: a new therapeutic concept for the management of oral manifestations of graft-versus-host disease

Ultraviolet irradiation inhibits the proliferative responses of lymphoid cells to mitogens and alloantigens by inactivation of T lymphocytes and antigen-presenting cells. Its immunosuppressive capacity led to the introduction of UV irradiation into clinical practice for the treatment of dermatologic manifestations of chronic graft-versus-host disease. The cumulative experience with psoralen-UV-A rays in the treatment of cutaneous and oral graft-versus-host disease was the incentive for the application of oral UV-B rays in 2 patients with oral graft-versus-host disease signs and symptoms after allogeneic marrow transplantation. Intraoral UV-B irradiation (0.02 mJ/cm(2)) was administered 2 or 3 times per week on an ambulatory basis; the dose was increased by 0. 02 mJ/cm(2) every fourth session. Both patients responded early and satisfactorily, displaying only minimal side effects at a relatively low cumulative dose. Intraoral UV-B proved a valuable modality in the treatment of resistant chronic oral graft-versus-host disease.

Half-side comparison of erythemogenic versus suberythemogenic UVA doses in oral photochemotherapy of psoriasis

BACKGROUND

Early American and European multicenter trials on the efficacy of photochemotherapy (PUVA) for psoriasis have clearly shown that the treatment protocol has a crucial impact on the cumulative UVA dose required for clearing patients. Most, if not all, treatment protocols rely on the PUVA-induced erythema as a guideline for UVA dosimetry.

OBJECTIVE

Our aim was to investigate whether phototoxic erythema is integral to an optimized PUVA protocol or reflects an unnecessary overexposure of patients.

METHODS

A standard high-dose UVA regimen using minimal phototoxic doses (MPD) was compared against two different low-dose regimens. To this purpose a bilateral comparison study was performed on 31 patients and divided in two parts. In the first trial on 14 patients, half of each patient's body was irradiated at each visit with 1 MPD, whereas the other half received only two thirds of the MPD. In the second trial on 17 patients treatment with 1 MPD was compared against treatment with one half of the MPD.

RESULTS

A total of 27 patients (12 patients in the first trial, 15 patients in the second trial) completed the study. In both trials the suberythemogenic doses were therapeutically as effective as the minimal phototoxic doses.

CONCLUSION

We conclude that PUVA-induced erythema is not a prerequisite for effective psoriasis treatment and that a low-dose UVA regimen is a promising approach to increase the short- and long-term safety of photochemotherapy.

Human papillomavirus and the development of non-melanoma skin cancer

Human papillomaviruses (HPV) are increasingly recognised as important human carcinogens. The best established association with human malignancy is that of high-risk mucosal HPV types and anogenital cancer. HPV-induced transformation of anogenital epithelia has been the subject of intense research which has identified the cellular tumour suppressor gene products, p53 and pRB, as important targets for the viral oncoproteins E6 and E7 respectively. Certain HPV types are also strongly associated with the development of non-melanoma skin cancer in the inherited disorder epidermodysplasia verruciformis (EV). However, in contrast with anogenital malignancy the oncogenic mechanisms of EV-HPV types remain uncertain, and there appears to be a crucial additional requirement for ultraviolet radiation. Cutaneous HPV types in the general population are predominantly associated with benign viral warts, but a role in non-melanoma skin cancer has recently been postulated. Polymerase chain reaction based HPV detection techniques have shown a high prevalence of HPV DNA, particularly in skin cancers from immunosuppressed patients and to a lesser extent in malignancies from otherwise immunocompetent individuals. No particular HPV type has yet emerged as predominant, and the role of HPV in cutaneous malignancy is unclear at present. It remains to be established whether HPV plays an active or purely a passenger role in the evolution of non-melanoma skin cancer.

Malignant tumours and psoriasis: a follow-up study

This nationwide follow-up study concerns the pattern of malignant tumours in a cohort of patients with psoriasis, at an average of 9.3 years after discharge from hospital. The study confirms that the significantly increased risk of cancer in these patients, amounting to 1.4 times that in the general population, is mainly due to cancer of the skin and lung in both sexes and cancer of the pharynx and larynx in men. Non-melanoma skin cancer is the most common malignancy, occurring in 196 of 795 patients with cancer: standardized incidence ratio (SIR, the ratio of observed to expected cancers) 2.4 for men and 2.6 for women. This means an overall lifetime risk (up to the age of 75 years) of 14.1%. In particular, squamous cell carcinoma (SCC) by itself (n = 45, SIR 3.9 for men and 4.7 for women), cancer in multiple sites (SIR 5.9 for basal cell carcinoma (BCC) and 11.7 for (SCC) and SCC on the lower extremities (SIR 18.0) are frequent. Women run the highest risk of BCC in the age range 20-40 years, while men in the age range 30-60 years run a particularly high risk of SCC. When monitoring patients extensively treated for psoriasis, this aberrant pattern of cancer should be taken into account.

PUVA therapy: current concerns in Japan

Photochemotherapy using methoxsalen in combination with long-wave ultraviolet light (PUVA) is an essential modality in the treatment of various skin diseases. Major therapeutic regimens include oral, topical and water-delivery methods. An adequate regimen should be chosen regarding cases of disease, extent of involvement and the age of patients. In Japan, however, treatment techniques and protocols have not yet been standardized. PUVA therapy may be a first choice in the early stages of mycosis fungoides and a second choice or an adjunctive measure in other diseases, such as psoriasis, vitiligo and atopic dermatitis, which have been disabling or resistant to conventional treatments. Japanese guidelines for PUVA therapy of psoriasis are being prepared to be produced. Risks and benefits must be weighed and the patient orientation is necessary to complete the treatment and also to minimize side-effects. Although possible risks for skin cancers in Japanese patients have been reported to be much lower, a careful monitoring of the patient's skin changes is recommended. While action mechanisms are not completely understood, recent investigations suggest that both antiproliferative and immunomodulatory effects are involved. This review article deals with the recent progress in clinical and basic research on PUVA therapy, focusing on our current concerns.

Prevalence of antibodies against virus-like particles of Epidermodysplasia verruciformis-associated HPV8 in patients at risk of skin cancer

There is increasing evidence for widespread occurrences of infection with Epidermodysplasia verruciformis-related human papillomaviruses, both in the general population and in immunosuppressed patients. In order to test for the prevalence of antibodies directed against the native L1 epitopes exposed on the surface of the virions, we have established an IgG-specific enzyme-linked immunosorbent assay with L1 virus-like particles of the Epidermodysplasia verruciformis-specific human papillomavirus 8 as antigen to screen 567 representative serum samples from the general population and immunosuppressed/dermatologic patients. Among healthy European donors (n = 210), 7.6% were found to be seropositive. In a group of renal transplant recipients (n = 185) the antibody prevalence was elevated to 21.1%, irrespective of the presence or absence of skin cancer. High positivity rates could be detected among (i) immunocompetent patients with nonmelanoma skin tumors (45.6%, n = 79) and (ii) Psoralene/UVA treated psoriasis patients (42.9%, n = 42). In contrast, anti-human papillomavirus 8-virus-like particle antibodies were found in only 6.8% of Hodgkin lymphoma patients (n = 44).

Detection of human papillomavirus DNA in PUVA-associated non-melanoma skin cancers

Psoralen and UVA (PUVA) photochemotherapy is associated with a dose-dependent increased risk of nonmelanoma skin cancer in patients treated for psoriasis. Like ultraviolet B radiation, PUVA is both mutagenic and immunosuppressive and may thus act as a complete carcinogen; however, the reversed squamous to basal cell carcinoma ratio (SCC:BCC) in PUVA-treated patients, also seen in immunosuppressed renal transplant recipients, suggests a possible cofactor role for human papillomavirus (HPV) infection. In this study we examine a large series of benign and malignant cutaneous lesions for the presence of HPV DNA from patients treated with high dose (> or =500 J per cm2) ultraviolet A. A panel of degenerate primers based on the L1 (major capsid protein) open reading frame was employed, designed to detect mucosal, cutaneous, and epidermodysplasia verruciformis HPV types with high sensitivity and specificity. HPV DNA was detected in 15 of 20 (75%) non-melanoma skin cancer, seven of 17 (41.2%) dysplastic PUVA keratoses, four of five (80%) skin warts, and four of 12 (33%) PUVA-exposed normal skin samples. The majority of HPV positive lesions contained epidermodysplasia verruciformis-related HPV including HPV-5, -20, -21, -23, -24, and -38. Possible novel epidermodysplasia verruciformis types were identified in further lesions. Mixed infection with epidermodysplasia verruciformis, cutaneous, and/or mucosal types was present in six of 30 (20%) of all HPV positive lesions, including in normal skin, warts, dysplastic PUVA keratoses, and squamous cell carcinomas. The prevalence and type of HPV infection in cutaneous lesions from PUVA-treated patients is similar to that previously reported in renal transplant-associated skin lesions, and suggests that the role of HPV in PUVA-associated carcinogenesis merits further study.

Systemic treatment of severe psoriasis

Severe psoriasis presents a difficult therapeutic challenge. Some modalities such as synthetic retinoids, phototherapy and methotrexate have been available for many years and need reappraisal, cyclosporin has only recently become available and requires careful administration. In this article we focus on the therapeutic modalities available to the dermatologist in Australia.

Oxyradical-mediated clastogenic plasma factors in psoriasis: increase in clastogenic activity after PUVA

Psoriasis is a common skin disorder characterized by hyperproliferation and incomplete differentiation of epidermal keratinocytes. Psoralen plus UVA (PUVA) is one of the treatments proposed for this disease. We had reported previously that exposure of regular blood cultures from healthy donors to PUVA leads to chromosomal breakage via the formation of transferable clastogenic materials, a phenomenon inhibitable by superoxide dismutase. In the present paper we show that these clastogenic factors (CF) are also formed in vivo. The CF were found in about 50% of the psoriasis patients studied (14 out of 31). In PUVA-treated psoriasis patients, the clastogenic activity of the plasma increased significantly between the first and the last (16th) exposure to PUVA. We hypothesize that CF formation in psoriasis is similar to that in other diseases accompanied by oxidative stress, in particular chronic inflammatory diseases with autoimmune reactions such as lupus erythematosus, progressive systemic sclerosis, rheumatoid arthritis and others. Increased superoxide production by phagocytes, formation of lipid peroxidation products and release of cytokines are considered to be responsible for the superoxide-stimulating and chromosome-damaging properties of patients' plasma. During PUVA therapy, superoxide generated via the interaction of psoralen with UVA may contribute to CF formation in addition to superoxide from inflammatory cells. An increased risk of cancer and leukemia is observed in diseases accompanied by CF formation. Therefore CF may contribute to the well-known risk of photocarcinogenesis by PUVA therapy. This additional risk may be preventable by antioxidants and superoxide scavengers.

p53 mutation in squamous cell carcinomas from psoriasis patients treated with psoralen + UVA (PUVA)

Individuals suffering from psoriasis are treated with a combination of psoralen and UVA radiation, commonly referred to as "PUVA" therapy. Epidemiologic studies have shown that PUVA therapy is a risk factor for skin cancer in psoriasis patients. Although PUVA treatment induces skin cancer in laboratory animals, it is unknown whether the increased incidence of skin cancer reported in PUVA-treated psoriasis patients is due to the carcinogenic effects of PUVA or due to other factors such as UVB. Because UV and PUVA induce different types of DNA damage resulting in unique types of p53 mutation, we investigated whether skin cancers from PUVA-treated psoriasis patients have PUVA-type or UV-type p53 mutations. Analysis of 17 squamous cell carcinomas (SCCs) from Austrian PUVA-treated patients revealed a total of 25 p53 mutations in 11 SCCs. A majority of p53 mutations occurred at 5'TpG sites. Although previous studies have shown that 5'TpA sites are the primary targets for PUVA mutagenesis, substitutions at 5'TpG sites are also quite common. Interestingly, a sizable portion of p53 mutations detected were C-->T or CC-->TT transitions, characteristic of UV-induced mutations. Because some psoriasis patients had substantial exposure to UVB before PUVA therapy and because the light sources used in PUVA therapy contained small but significant wavelengths in the UVB region, it is possible that the C-->T and CC-->TT transitions detected in SCCs from PUVA-treated patients were induced by UVB. Nonetheless, our results indicate that both PUVA and UVB may play a role in the development of skin cancer in Austrian psoriasis patients who undergo PUVA therapy.