Ultraviolet B induces mast cell apoptosis: a hypothetical mechanism of ultraviolet B treatment for uraemic pruritus

Pruritus in Chronic Kidney Disease: An Update

Chronic kidney disease-associated pruritus (CKDaP) is an often under-diagnosed and under-recognized condition, despite its considerable prevalence within the chronic kidney disease (CKD) population. Universally accepted guidelines are also lacking. The true prevalence of CKDaP worldwide therefore remains unknown, although its negative impact on mortality and health-related quality of life outcomes is very clear. The pathophysiological mechanisms leading to the onset of CKDaP are only partly understood. CKDaP is currently believed to be caused by a multifactorial process, from local skin changes, metabolic alterations, the development of neuropathy and dysregulation of opioid pathways, and psychological factors. Much work has been carried out towards a more systematic and structured approach to clinical diagnosis. Various tools are now available to assess the severity of CKDaP. Many of these tools require greater validation before they can be incorporated into the guidelines and into routine clinical practice. Further efforts are also needed in order to increase the awareness of clinicians and patients so that they can identify the CKDaP signs and symptoms in a timely manner. Currently established treatment options for CKDaP focus on the prevention of xerosis via topical emollients, the optimization of dialysis management, early referral to kidney transplantation if appropriate, oral antihistamine, and a variety of neuropathic agents. Other novel treatment options include the following: topical analgesics, topical tacrolimus, cannabinoid-containing compounds, antidepressants, oral leukotrienes, opioids, and non-pharmacological alternative therapies (i.e., phototherapy, dietary supplements, acupuncture/acupressure). We provide an updated review on the evidence relating to the epidemiology, the pathophysiology, the clinical assessment and diagnosis, and the management of CKDaP.

Unravelling the pathophysiology of chronic kidney disease-associated pruritus

For decades, itch related to chronic kidney disease (CKDaP) has been a clinical problem, but the aetiology and pathophysiology of CKDaP are still not yet fully understood—currently the underlying pathophysiological mechanisms are thought to be multifactorial. As new therapeutic targets have recently been identified and clinical trials have shown promising results, our current understanding of the interrelationships has expanded significantly. Here we review the pathophysiology and recent findings on modulation and sensitization of itch contributing to the development of CKDaP, covering hypothesis regarding immune system dysfunction, metabolic changes, uremic toxin deposition, peripheral neuropathy and imbalances in the endogenous opioid system.

Clinical management of chronic kidney disease-associated pruritus: current treatment options and future approaches

Chronic kidney disease (CKD)-associated pruritus (CKD-aP) is an underdiagnosed yet severely distressing condition that impacts 60% of patients on dialysis and many nondialysis patients with Stages 3–5 CKD. However, despite its high prevalence, there are currently limited treatment options available for these patients and a lack of treatment guidelines for clinicians. In this manuscript, we reviewed the available literature in order to evaluate the current management and treatment options for CKD-aP, including dialysis management, topical treatments, gabapentinoids, opioids and alternative medicine. We also review the available data on CKD-aP treatments in development and propose new guidelines for managing patients with CKD-aP.

Role of Mast Cells in the Pathogenesis of Pruritus in Mastocytosis

Pruritus can be defined as an unpleasant sensation that evokes a desire to scratch and significantly impairs patients' quality of life. Pruritus is widely observed in many dermatoses, including mastocytosis, a rare disease characterized by abnormal accumulation of mast cells, which can involve skin, bone marrow, and other organs. Increasing evidence highlights the role of mast cells in neurogenic inflammation and itching. Mast cells release various pruritogenic mediators, initiating subsequent mutual communication with specific nociceptors on sensory nerve fibres. Among important mediators released by mast cells that induce pruritus, one can distinguish histamine, serotonin, proteases, as well as various cytokines. During neuronal-induced inflammation, mast cells may respond to numerous mediators, including neuropeptides, such as substance P, neurokinin A, calcitonin gene-related peptide, endothelin 1, and nerve growth factor. Currently, treatment of pruritus in mastocytosis is focused on alleviating the effects of mediators secreted by mast cells. However, a deeper understanding of the intricacies of the neurobiology of this disease could help to provide better treatment options for patients.

Chronic Kidney Disease-Associated Itch (CKD-aI) in Children-A Narrative Review

Chronic kidney disease (CKD) is a condition of widespread epidemiology and serious consequences affecting all organs of the organism and associated with significant mortality. The knowledge on CKD is rapidly evolving, especially concerning adults. Recently, more data is also appearing regarding CKD in children. Chronic itch (CI) is a common symptom appearing due to various underlying dermatological and systemic conditions. CI may also appear in association with CKD and is termed chronic kidney disease-associated itch (CKD-aI). CKD-aI is relatively well-described in the literature concerning adults, yet it also affects children. Unfortunately, the data on paediatric CKD-aI is particularly scarce. This narrative review aims to describe various aspects of CKD-aI with an emphasis on children, based on the available data in this population and the data extrapolated from adults. Its pathogenesis is described in details, focusing on the growing role of uraemic toxins (UTs), as well as immune dysfunction, altered opioid transmission, infectious agents, xerosis, neuropathy and dialysis-associated aspects. Moreover, epidemiological and clinical aspects are reviewed based on the few data on CKD-aI in children, whereas treatment recommendations are proposed as well, based on the literature on CKD-aI in adults and own experience in managing CI in children.

Infiltration of Mast Cells in Scalp Biopsies of Patients with Alopcia Areata or Androgenic Alopecia Versus Healthy Individuals: A Case Control Study

BACKGROUND

Alopecia areata (AA) and androgenic alopecia (AGA) are of the most common types of alopecias. Recently, the role of mastcells in inflammatory diseases has become the focus of many studies. However, few studies have been conducted on their role in AA and AGA. Therefore, our study aimed to quantitatively evaluate the presence of mastcells in the AA and AGA specimens.

MATERIALS AND METHODS

Three groups of AA, AGA, and healthy control were studied (each group with 20 subjects). Patients were randomly selected from those referred to the dermatology clinics of Shahid Beheshti University. Specimens were obtained from the scalp, and perifollicular and perivascular areas were investigated.

RESULTS

Significantly higher perifollicular and perivascular mastcell counts were seen in both AGA and AA groups as compared to healthy control (P<0.001 for both). Moreover, AA patients had more frequent perivascular mastcells than the AGA group (P=0.042). Among patients aged <40 years, perifollicular and perivascular mastcell counts were not significantly different among three groups; however, subjects over 40 years of age in both groups had significantly more perifollicular and perivascular mastcells than healthy participants. There was a significant positive correlation between disease severity and mast cell counts in both perifollicular and perivascular areas in AA patients (P=0.001 for both).

CONCLUSION

There is a significantly increased infiltration of mastcells in AA and AGA patients, and this increase is age and severity dependent. Moreover, the increase in mastcell proliferation is more dominant in AA patients.

Scalp Pruritus: Review of the Pathogenesis, Diagnosis, and Management

Scalp pruritus is a frequent problem encountered in dermatological practice. This disorder is caused by various underlying diseases and is a diagnostic and therapeutic challenge. Scalp pruritus may be localized to the scalp or extended to other body areas. It is sometimes not only associated with skin diseases or specific skin changes, but also associated with lesions secondary to rubbing or scratching. Moreover, scalp pruritus may be difficult to diagnose and manage and may have a great impact on the quality of life of patients. It can be classified as dermatologic, neuropathic, systemic, and psychogenic scalp pruritus based on the potential underlying disease. A thorough evaluation of patients presenting with scalp pruritus is important. Taking history and performing physical examination and further investigations are essential for diagnosis. Therapeutic strategy comprises removal of the aggravating factors and appropriate treatment of the underlying condition. All treatments should be performed considering an individual approach. This review article focuses on the understanding of the pathophysiology and the diagnostic and therapeutic management of scalp pruritus.

Role of Adjuvant Narrow Band Ultraviolet B Phototherapy in the Treatment of Chronic Urticaria

Background:

Chronic urticaria is a common dermatological disorder that causes a great deal of distress in patients and affects daily life. Narrow band ultraviolet B (NBUVB) has been shown to be an effective treatment in chronic urticaria in few studies. However, the data regarding its role in chronic urticaria are limited.

Aims and Objectives:

The aim of this study was to determine the role of NBUVB in the treatment of chronic urticaria in combination with antihistamine.

Materials and Methods:

A total of 80 patients of chronic urticaria were recruited, out of which 40 were allocated to NBUVB-loratadine group and 40 to loratadine group. Patients were assessed using urticaria activity score (UAS) at same point of time, i.e. after 4 weeks (8 sessions), 8 weeks (16 sessions) and at follow up of 4 weeks after stopping the treatment.

Results:

On comparing the two groups, the mean UAS was significantly lower after 8 and 16 sessions in NBUVB-loratadine group (12.03 v/s 21.43 and 3.54 v/s 17.16, respectively). The difference in reduction of UAS7 in two groups was seen to be statistically significant (P value < 0.01).

Conclusion:

Thus we conclude that NBUVB may be useful in the treatment of chronic urticaria.

The Antipruritic Effect of Phototherapy

Phototherapy is widely used to treat inflammatory skin diseases such as psoriasis and atopic dermatitis. Repeated suberythemogenic doses of UV-light reduce inflammation in these diseases and ultimately may lead to a complete disappearance of cutaneous symptoms for weeks or months. Chronic pruritus is an important and highly distressing symptom of many of these inflammatory skin diseases. Interestingly, pruritus is also reduced or completely abolished by UV-treatment of psoriasis and atopic dermatitis, and sometimes reduction of pruritus is the first indication for skin improvement by phototherapy. The cutaneous nervous system is an integral part of skin anatomy, and free nerve endings of sensory cutaneous nerve fibers reach up into the epidermis getting in close contact with epidermal cells and mediators from epidermal cells released into the intercellular space. Stimulation of “pruriceptors” within this group of sensory nerve fibers generates a neuronal signal eventually transmitted via the dorsal root and the spinal cord to the brain, where it is recognized as “itch”. UV-light may directly affect cutaneous sensory nerve fibers or, via the release of mediators from cells within the skin, indirectly modulate their function as well as the transmission of itch to the central nervous system inducing the clinically recognized antipruritic effect of phototherapy.

Phototherapy using narrowband ultraviolet B and psoralen plus ultraviolet A is beneficial in steroid-dependent antihistamine-refractory chronic urticaria: a randomized, prospective observer-blinded comparative study

BACKGROUND

Literature on the efficacy of phototherapy in steroid-dependent antihistamine-refractory chronic urticaria (CRU) is limited.

OBJECTIVES

To assess and compare the efficacy of psoralen plus ultraviolet A (PUVA) and narrowband ultraviolet B (NB-UVB) in steroid-dependent CRU.

METHODS

In this randomized, prospective observer-blinded comparative study, 50 patients with steroid-dependent CRU (6 months of spontaneous urticaria with no response after 3 consecutive months of antihistamines and steroid dependence) were administered either PUVA (group A) or NB-UVB (group B) for 90 days, with a post-treatment follow-up of 90 days. The treatment efficacy was assessed using the average urticaria activity score 7 (aUAS7) and outcome scoring scale (OSS) every 2 weeks.

RESULTS

The mean values of aUAS7 progressively decreased from 4·9 ± 0·8 and 5·0 ± 0·7 at baseline to 1·9 ± 0·7 and 1·4 ± 0·7 in groups A and B, respectively, by day 90. This further decreased to 1·5 ± 0·8 and 1·4 ± 1·0 at day 180 in both groups. The values of OSS progressively increased from baseline (1·6 ± 0·5 in group A and 1·3 ± 0·5 in group B) to 3·9 ± 0·3 and 4·0 ± 0·3 in groups A and B, respectively, by day 90, and 3·9 ± 0·5 and 4·0 ± 0·6 by day 180. NB-UVB fared statistically better than PUVA at different time points. Adverse events encountered were minimal and did not warrant treatment discontinuation.

CONCLUSIONS

Phototherapy, especially NB-UVB, is an effective, safe and affordable therapeutic modality for steroid-dependent CRU and should be tried prior to third-line treatment options such as omalizumab, ciclosporin and other immunosuppressants.

Risk of skin cancer in patients on chronic haemodialysis: a nationwide, population-based study in Taiwan

BACKGROUND

Patients on chronic haemodialysis (HD) have a higher incidence of cancer. However, the risk of skin cancer in this population has rarely been investigated.

OBJECTIVES

To investigate the risk of nonmelanoma skin cancer (NMSC) and cutaneous melanoma in patients on chronic HD and to explore the associated risk factors.

METHODS

We performed retrospective cohort and nested case-control studies using records in the Taiwanese National Health Insurance Research Database between 1999 and 2013. The HD cohort included 79 668 incident patients on HD, for whom the standardized incidence ratios (SIRs) for incident NMSC and cutaneous melanoma were determined. In the nested case-control study, patients on HD with NMSC were matched to those without skin cancers. The impact of various factors on the development of NMSC was determined by conditional logistic regression analysis.

RESULTS

Among the 79 668 patients on HD, 248 cases of NMSC and 22 cases of cutaneous melanoma occurred after a mean 4·95 years of follow-up. The SIRs for NMSC and cutaneous melanoma in patients on HD were 1·58 (95% confidence interval 1·39-1·79) and 1·44 (95% confidence interval 0·91-2·19), respectively. Of the patients on HD, a higher risk of NMSC was found in men (1·5-fold), South Taiwan residents (twofold) and patients with uraemic pruritus after long-term antihistamine treatment (1·53-fold). However, the incidence of NMSC was not increased in patients with uraemic pruritus receiving ultraviolet B phototherapy.

CONCLUSIONS

Patients on chronic HD are at higher risk of NMSC. Uraemic pruritus further increases the risk of NMSC, which might be prevented by ultraviolet B phototherapy.

Chronic pruritus in the elderly: pathophysiology, diagnosis and management

Chronic itch in the elderly is a common problem, with a significant impact on quality of life and sleep in elderly patients. Chronic itch may be attributable to several causes, including dry skin, immunosenescence and neural degeneration. Itch may also be caused by skin diseases, such as seborrhoeic dermatitis and stasis dermatitis; systemic conditions, such as end-stage renal disease and diabetes; and psychogenic conditions, such as depression and anxiety. The use of polypharmacy may also cause itch, with or without a rash. Specifically, thiazides and calcium channel blockers have been known to cause itch in elderly patients. Management should be tailored according to the underlying dermatological or systemic aetiology of itch. Topical treatment is the mainstay of therapy, providing special emphasis on skin hydration and barrier repair. In addition, topical and oral medications that target the nervous system and reduce neuronal hypersensitization, such as gabapentin and selective antidepressants, have a role in treating patients with severe chronic itch. Furthermore, management must account for changes in metabolism and pharmacokinetics of drugs in the aging population in order to prevent the occurrence of adverse effects.

A review of the use of tanning beds as a dermatological treatment

Introduction

In-office phototherapy is an effective treatment for many dermatologic conditions, however, many patients are unable to adhere to the rigorous travel and time commitments sometimes needed. Tanning bed facilities are nearly ubiquitous in modern society and could represent a more convenient means to obtain ultraviolet (UV) exposure when office phototherapy is not feasible. The purpose of this study was to review available evidence on the use of tanning facilities as a treatment for dermatologic conditions.

Methods

PubMed was searched on February 2015 for “tanning beds” and “phototherapy”, and with some dermatologic conditions sensitive to UV light, including “psoriasis”, “mycosis fungoides”, “acne”, “atopic dermatitis” and “eczema”. From there, further articles were found using the reference sections of the initial papers. A similar methodology was used with the Google Scholar search engine. Only articles in English and prospective studies were included in this review.

Results

We found studies validating the use of tanning facilities for psoriasis treatment. Use as a treatment option for atopic dermatitis, mycosis fungoides, acne, scleroderma, vitiligo, and pruritus, as well as other UV sensitive dermatoses, may also be beneficial. This study is limited by the lack of double-blind, placebo-controlled trials, long-term follow-up studies, and meta-analyses for tanning facility use in dermatologic phototherapy, and by the lack of standardization of both tanning facilities and exposure dosing.

Conclusion

Unsupervised sun exposure is a standard recommendation for some patients to obtain phototherapy. Selected use of commercial tanning beds in the treatment of dermatologic conditions may be another useful and effective treatment for those patients with an inability to access office-based or home-based phototherapy.

Electronic supplementary material

The online version of this article (doi:10.1007/s13555-015-0071-8) contains supplementary material, which is available to authorized users.

Comparative study of systemic psoralen and ultraviolet A and narrowband ultraviolet B in treatment of chronic urticaria

BACKGROUND

Previous success rates of psoralen and ultraviolet A (PUVA) and narrowband UVB (NB-UVB) in the treatment of chronic urticaria are reported in few studies with no previous reports on the comparable efficacy of both modalities in the disease.

AIM

We aimed to compare the efficacy of PUVA versus NB-UVB in the treatment of chronic urticaria.

METHODS

Twenty-four patients with chronic urticaria were included and divided into two groups: 12 patients subjected to PUVA and 12 subjected to NB-UVB. They were compared according to the urticaria Total Severity Score (TSS) before and after treatment, cumulative dose, and side effects.

RESULTS

There was a statistically significant decrease in urticaria TSS in both the NB-UVB- and PUVA-treated groups after than before treatment (P < 0.05), with no significant difference between both groups regarding the percentage of improved patients and the mean decrease of urticaria TSS (P > 0.05). Gastrointestinal upset was reported at a significantly higher percentage in the PUVA-treated group than in the NB-UVB-treated group.

CONCLUSION

Both NB-UVB and PUVA show comparable efficacy in the treatment of chronic urticaria with minimal reversible side effects.

Differences in epidermal thickness and expression of apoptosis regulatory proteins in the skin of patients with chronic renal failure and pruritus

Chronic renal failure is often associated with skin itching (pruritus) in dialysis patients. In order to investigate the possible causes of pruritus, the epidermis of the thigh of 12 dialysis patients and 4 controls from patients without renal disease were examined. The sections of the epidermis were measured and immunohistochemically analyzed using antibodies to Bcl-2, Bax, caspase-3 proteins and TUNEL method. While the mean thickness of normal epidermis was 53 μm, in dialysis patients it ranged between 23 and 34 μm during the 3-5 year period on dialysis. Compared to normal skin, the fine balance between the Bcl-2 and Bax proteins did not greatly change in the epidermis of dialysis patients during the three years of dialysis. Following five-year dialysis, the epidermis displayed increased Bax and decreased Bcl-2 expression in the basal and intermediate epidermal layers, as well as the presence of apoptotic cells (TUNEL and caspase-3 positive) both in the superficial and intermediate epidermal layers. Our study demonstrated the predominant expression of cell death Bax proteins over cell survival Bcl-2 proteins, and apoptotic cells in the deeper layers of the epidermis in patients on long-term dialysis. We speculate that the thinning of the epidermis might be associated with the appearance of dead cells in the deeper epidermal layers, while the changed internal milieu of epidermal cells could possibly affect the intra-epidermal nerve endings thus leading to the sensation of pruritus.

Narrowband ultraviolet B (311 nm, TL01) phototherapy in chronic ordinary urticaria

BACKGROUND

Chronic ordinary urticaria (COU) can severely reduce quality of life and be difficult to control. Ultraviolet (UV) A and UVB phototherapy has been reported to decrease the release of histamine from either mast cells and/or basophils. Previous small studies have suggested that UVB phototherapy is a good alternative treatment for COU.

OBJECTIVES

The purpose of this study was to assess the efficacy of narrow-band UVB (NB-UVB) phototherapy for COU.

MATERIALS AND METHODS

Twenty-two patients (three male, 19 female) received NB-UVB phototherapy. These patients had not responded to at least two H1 antihistamines, and most had been treated with a variety of antihistamine combinations. Clinical responses were assessed according to an outcome scoring scale. During both visits, patients were administered the following: the visual analogue scale (VAS) on present pruritus and/or whealing; chronic urticaria impact on patients' quality of life according to the interference with daily activities, quality of sleep, and flare-up rates.

RESULTS

The median number of treatments was 31.4 (9-44), and the mean top dose was 9.46 J/cm(2) (1.1-16.4 J/cm(2)). NB-UVB treatment led to clearance in 10 patients (45%), marked improvement in five (22%), and moderate improvement in seven (31%) patients according to an outcome scoring scale. Mild side effects were observed in two patients. Six patients who cleared or observed marked improvement remained clear at follow-up for a period of six months to one year, and other patients had a few recurrent lesions that did not need retreatment. For VAS scores and total chronic urticaria impact on patients' quality of life scores, the differences between baseline and after treatment scores were significantly lower (P < 0.001, P < 0.001, respectively).

CONCLUSION

Narrow-band UVB (NB-UVB) therapy is an effective, well-tolerated treatment option in second-line therapy for COU. This therapy can lead to subjective relief of pruritus and whealing and objective reduction of whealing. Further larger studies with longer follow-up periods are necessary to determine the proper clinical response and long-term complications of this therapy in COU.

Narrowband ultraviolet B phototherapy for patients with refractory uraemic pruritus: a randomized controlled trial

BACKGROUND

Pruritus is very common in uraemic patients, but the treatment remains challenging. Studies regarding narrowband ultraviolet B (NB-UVB) phototherapy for uraemic pruritus are rare.

OBJECTIVES

To investigate whether or not NB-UVB phototherapy is an effective treatment for uraemic pruritus.

METHODS

We conducted a single-blind, randomized, controlled trial for patients with refractory uraemic pruritus. The treatment group received NB-UVB phototherapy three times per week for 6 weeks. The dose of NB-UVB started from 210 mJ cm(-2) and was increased by 10% each time. The control group received time-matched exposures to long-wave UVA radiation. A visual analogue scale (VAS) score was evaluated weekly for pruritus intensity for 12 weeks. The characteristics of pruritus were also assessed by a questionnaire at baseline and after 6 weeks of phototherapy.

RESULTS

Both the NB-UVB and control groups had significant and comparable improvement in the pruritus intensity VAS scores during the period of phototherapy and follow-up. Compared with the control group, the NB-UVB group showed a significant improvement in the involved body surface area affected by pruritus (P = 0·006), but not in sleep quality. More detailed regression and estimating analysis revealed that the patients in the NB-UVB group had lower pruritus intensity scores at week 6, week 10 and week 12. This may indicate a beneficial difference at certain time points, but the effect seems marginal.

CONCLUSIONS

NB-UVB phototherapy does not show a significant effect in reducing pruritus intensity compared with a control group for refractory uraemic pruritus. Further studies are warranted.

Allergic diseases in the elderly

Demographic distribution of the population is progressively changing with the proportion of elderly persons increasing in most societies. This entails that there is a need to evaluate the impact of common diseases, such as asthma and other allergic conditions, in this age segment. Frailty, comorbidities and polymedication are some of the factors that condition management in geriatric patients. The objective of this review is to highlight the characteristics of allergic diseases in older age groups, from the influence of immunosenescence, to particular clinical implications and management issues, such as drug interactions or age-related side effects.

Pruritus in the elderly

Pruritus is an unpleasant sensation leading to the desire to scratch. It is the most common symptom in dermatology, and various skin and systemic diseases can be associated with the presence of itching. Pruritus may also be provoked by numerous drugs. Although the exact epidemiologic data are still absent, it is generally accepted that elderly people frequently suffer from pruritus, and the problem of itching in this population remains a challenge for clinicians. The elderly often complain of numerous comorbidities that complicate the determination of the cause of pruritus, as well as its treatment. Physical and mental deprivation may complicate proper assessment of pruritus severity and negatively impair compliance with complex antipruritic therapies. Taking also into account heterogeneity of possible causes of pruritus, every patient with pruritus must be handled individually, regarding the diagnostic procedures and antipruritic therapy.

Chronic pruritus: clinics and treatment

Chronic pruritus, one of the main symptoms in dermatology, is often intractable and has a high impact on patient's quality of life. Beyond dermatologic disorders, chronic pruritus is associated with systemic, neurologic as well as psychologic diseases. The pathogenesis of acute and chronic (>6 weeks duration) pruritus is complex and involves in the skin a network of resident (e.g., sensory neurons) and transient inflammatory cells (e.g., lymphocytes). In the skin, several classes of histamine-sensitive or histamine-insensitve C-fibers are involved in itch transmission. Specific receptors have been discovered on cutaneous and spinal neurons to be exclusively involved in the processing of pruritic signals. Chronic pruritus is notoriously difficult to treat. Newer insights into the underlying pathogenesis of pruritus have enabled novel treatment approaches that target the pruritus-specific pathophysiological mechanism. For example, neurokinin-1 antagonists have been found to relieve chronic pruritus.

UV-based therapy and vitamin D

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

Evaluation of chronic pruritus in older patients

Chronic pruritus, one of the main symptoms in dermatologic diseases, is often intractable and has a high impact on a patient´s quality of life. In addition to dermatologic disorders, chronic pruritus is associated with systemic and neurologic, as well as psychologic, diseases. Aging skin is considered to be more susceptible to pruritic disorders. Thus, owing to demographic changes, pruritus is becoming more prevalent. The elderly are often afflicted with comorbidities and polypharmacy, which can complicate diagnosis and therapy. In this review we present a rational work-up adapted to the special premises and needs of geriatric patients. This may facilitate the choice of suitable therapeutic regimens.

An update on pruritus associated with CKD

The prevalence of chronic kidney disease (CKD) and end-stage renal disease is increasing worldwide. Despite improvements in dialysis methods, including the development of novel biocompatible membranes and ultrapure dialysate, CKD-associated pruritus remains a common and significant public health issue. Not only does this distressing symptom profoundly impact on quality of life and sleep, recent evidence showed that pruritus also was associated with poor patient outcome. Nonetheless, nephrologists and other health care professionals often fail to recognize and adequately address the pruritus associated with CKD. The pathophysiological mechanism of CKD-associated pruritus is poorly defined, and, as a result, the development of specific therapies has proved to be a challenge. The purpose of this review is to highlight the importance of this neglected topic by providing an overview of recent epidemiological studies, outcomes data, proposed pathophysiological mechanisms, and emerging treatment options.

Generalized pruritus treated with narrowband UVB

BACKGROUND

Narrowband UVB phototherapy has been increasingly used in a variety of dermatological diseases. We planned to evaluate its efficacy in generalized pruritus in this prospective study.

METHODS

Forty-six patients were included and then divided into two groups: group 1 and group 2 consisted of patients with uremic pruritus and "idiopathic pruritus", respectively. Phototherapy was given three times a week. Efficacy assessments were made by means of visual analog scale (VAS) and pruritus grading score.

RESULTS

Thirty-five patients completed the treatment. Mean VAS decreased from 8.2 +/- 1.5 to 3.6 +/- 3 in group 1 and from 7.1 +/- 2.3 to 2.3 +/- 2.8 in group 2 (P < 0.0001). Mean percentage of change in VAS was 54.2% (95% CI 32.6-75.9) and 67.9% (95% CI 53.8-81.9) in group 1 and group 2, respectively. Mean number of treatments was 22 in both groups. Mean cumulative UVB dose was 24,540 mJ/cm(2) and 20,801 mJ/cm(2) in group 1 and group 2, respectively.

CONCLUSION

Narrowband UVB is an effective and well-tolerated treatment option for patients with generalized pruritus.

Treatment of uremic pruritus with narrowband ultraviolet B phototherapy: an open pilot study

We report the results of a pilot study of narrowband ultraviolet B phototherapy for the treatment of 20 patients with uremic pruritus. Ten patients completed the 6-week study period. A total of 8 patients were found to be responders. Of the remaining 10 patients who left the study before 6 weeks, 6 were satisfied with the response. In the follow-up period, 7 responders could be examined, and 3 were in remission 6 months after completing treatment. However, pruritus recurred in the remaining 4 responders. Narrowband ultraviolet B phototherapy may be an effective treatment for patients with uremic pruritus. Recurrence of pruritus, however, is a frequent problem.

Ultraviolet phototherapy for pruritus

Ultraviolet-based therapy has been used to treat various pruritic conditions including pruritus in chronic renal failure, atopic dermatitis, HIV, aquagenic pruritus and urticaria, solar, chronic, and idiopathic urticaria, urticaria pigmentosa, polycythemia vera, pruritic folliculitis of pregnancy, breast carcinoma skin infiltration, Hodgkin's lymphoma, chronic liver disease, and acquired perforating dermatosis, among others. Various mechanisms of action for phototherapy have been posited. Treatment limitations, side effects, and common dosing protocols are reviewed.

Phototherapy with narrowband vs broadband UVB

Phototherapy with ultraviolet (UV) radiation of wavelengths between 280 and 320 nm (UVB) is a safe and effective treatment for a variety of diseases. In addition to standard broadband UVB (bUVB), narrowband phototherapy with fluorescent bulbs emitting near monochromatic UV around 311 nm (nUVB) has become an important treatment for diseases such as psoriasis, atopic dermatitis and vitiligo. In addition to these indications, the number of diseases for which nUVB phototherapy is reported to be effective is continuously growing. The differential effects of nUVB phototherapy in comparison to other UV wavelengths as well as established and new indications for this treatment modality are reviewed.

Ultraviolet irradiation induces apoptosis in human immature, but not in skin mast cells

As diverse pruritic cutaneous diseases respond to ultraviolet treatment, we have examined whether ultraviolet light is capable of inducing apoptosis in mast cells. Human mast cell line 1 (HMC1) derived from a patient with malignant mastocytosis and purified skin mast cells were irradiated with single doses of ultraviolet B or ultraviolet A1, or pretreated with 8-methoxypsoralen prior to ultraviolet A1 exposure. After 0 to 48 h of incubation, the percentage of apoptotic and dead cells was assessed. In HMC1 cells, morphologic features of apoptosis were further evaluated by electron microscopy. All ultraviolet treatment induced apoptosis of HMC1 cells in a time- and dose-dependent manner. Apoptosis was associated with activation of caspase-3, release of cytochrome C, cleavage of poly(ADP-ribose)-polymerase, and nuclear accumulation of p53. In contrast, resting skin mast cells were resistant to ultraviolet light induced apoptosis. After incubation with stem cell factor and interleukin-4 for 2 wk, however, slowly proliferating skin mast cells also underwent apoptosis in response to ultraviolet light. In conclusion, these data demonstrate that ultraviolet light directly affects mast cells, but mainly aims at the proliferating mast cells as found in mastocytosis and mast cell dependent pruritic diseases, where increased numbers are observed due to the recruitment mast cell precursors from the blood.