Phototherapy for Itch

What's New in Cutaneous T-Cell Lymphoma-Associated Pruritus

Cutaneous T-cell lymphomas are a heterogenous group of lymphomas that cause various skin manifestations. Severe pruritus occurs frequently in cutaneous T-cell lymphoma and negatively impacts patients' quality of life. The pathophysiology of cutaneous T-cell lymphoma-associated itch is complex and involves various immune cells, inflammatory cytokines, and neuroimmune interactions. Treating cutaneous T-cell lymphoma pruritus can be challenging, and there have been few randomized controlled studies evaluating the use of antipruritic treatments in these patients. Systemic therapies targeting the disease have also been shown to have some antipruritic effects. Furthermore, although biologic therapy has revolutionized the treatment of other pruritic skin conditions, the use of biologics in cutaneous T-cell lymphoma remains controversial.

Phototherapy for Generalized Pruritus of Unknown Origin: Single-Center Experience

OBJECTIVE

Phototherapy is a well-established therapy in dermatology. However, there is limited evidence regarding phototherapy for the treatment of generalized pruritus of unknown origin (GPUO). The objective of this study was to assess the efficacy and safety of narrowband ultraviolet B (NB-UVB) phototherapy in patients with GPUO.

METHODS

Researchers conducted a retrospective review of the treatment outcomes of patients with GPUO who were treated with NB-UVB between 2004 and 2019 at their facility.

RESULTS

Investigators included 67 patients diagnosed with GPUO treated with NB-UVB. Complete remission was achieved in more than 70% of the patients. No serious adverse events were documented.

CONCLUSIONS

For patients with GPUO, NB-UVB may be a safe and effective treatment option.

An Update on Narrowband Ultraviolet B Therapy for the Treatment of Skin Diseases

The objective of this review is to provide an update on narrowband ultraviolet B (NB-UVB) as a treatment for various skin conditions. NB-UVB works by suppressing the cutaneous cell-mediated immune response and has been shown to be an efficacious and clinically tolerable treatment for a range of inflammatory dermatoses. A literature search was conducted by advanced searches of PubMed for NB-UVB treatment of dermatologic skin diseases with a focus on reports from 2010 to 2021, including both office-based and home-based phototherapy (HBPT). Data were prioritized based on studies with a high level of evidence using the Oxford Evidence-Based Medicine guidance.

We found that NB-UVB continues to serve as an effective form of therapy for several cutaneous conditions, including vitiligo, psoriasis, atopic dermatitis, mycosis fungoides, and other inflammatory dermatoses. The recent introduction of Janus kinase inhibitors in combination with NB-UVB suggests future promise in the treatment of vitiligo. Despite its rise in popularity, a decline was seen in office-based NB-UVB treatment during the coronavirus disease 2019 pandemic. Options are available to deliver NB-UVB at home with comparable efficacy to office-based treatments. In conclusion, for a select group of patients and conditions, NB-UVB continues to serve as an effective treatment modality with minimal side effects, with HBPT serving as an option to improve patient compliance.

Ketoprofen Combined with UVA Irradiation Exerts Higher Selectivity in the Mode of Action against Melanotic Melanoma Cells than against Normal Human Melanocytes

Malignant melanoma is responsible for the majority of skin cancer-related deaths. The methods of cancer treatment include surgical removal, chemotherapy, immunotherapy, and targeted therapy. However, neither of these methods gives satisfactory results. Therefore, the development of new anticancer therapeutic strategies is very important and may extend the life span of people suffering from melanoma. The aim of this study was to examine the effect of ketoprofen (KTP) and UVA radiation (UVAR) therapy on cell proliferation, apoptosis, and cell cycle distribution in both melanotic melanoma cells (COLO829) and human melanocytes (HEMn-DP) in relation to its supportive effect in the treatment of melanoma. The therapy combining the use of pre-incubation with KTP and UVAR causes a significant increase in the anti-proliferative properties of ketoprofen towards melanoma cells and the co-exposure of melanotic melanoma cells induced apoptosis shown as the mitochondrial membrane breakdown, cell-cycle deregulation, and DNA fragmentation. Moreover, co-treatment led to GSH depletion showing its pro-apoptotic effect dependent on ROS overproduction. The treatment did not show a significant effect on normal cells—melanocytes—which indicates its high selectivity. The results suggest a possible benefit from the use of the ketoprofen and ultraviolet A irradiation as a new concept of melanotic melanoma therapy.

Vulvar Pruritus: A Review of Clinical Associations, Pathophysiology and Therapeutic Management

Vulvar pruritus is an unpleasant sensation and frequent symptom associated with many dermatologic conditions, including infectious, inflammatory and neoplastic dermatoses affecting the female genitalia. It can lead to serious impairment of quality of life, impacting sexual function, relationships, sleep and self-esteem. In this review, common conditions associated with vulvar itch are discussed including atopic and contact dermatitis, lichen sclerosus, psoriasis and infectious vulvovaginitis. We review the potential physiologic, environmental and infectious factors that contribute to the development of vulvar itch and emphasize the importance of addressing their complex interplay when managing this disruptive and challenging symptom.

Comparative Study on Different Skin Pruritus Mouse Models

The animal model is an important tool to study the mechanism of disease formation. Different animal models of pruritus have been adopted based on the purpose of researchers in the study of the itching mechanism. Although the symptoms of various models are quite different, scratching behavior is a key indicator. Therefore, it is necessary to find an animal model that can quickly induce animal scratching and maintain the stability of scratching behavior. In this study, we compared animal models of pruritus induced by four substances and found that the scratching behavior of mice induced by urushiol not only reached the plateau stage quickly but also showed more stability in the plateau phase than that induced by 2,4-dinitrofluorobenzene, oxazolone, and imiquimod. Meanwhile, in the animal model induced by urushiol, the changes of epidermal thickening and inflammatory cell aggregation were also more obvious. In addition, pruritus induced by urushiol is prevalent all over the world, especially in the United States and Europe, involving outdoor groups such as firefighters, forest loggers, and farmers. Therefore, we believe that the urushiol-induced animal model is an ideal choice for the study of the itch formation mechanism and the development of antipruritic drugs.

Pathophysiology, diagnosis, and pharmacological treatment of prurigo nodularis

Introduction: Prurigo nodularis (PN) is a chronic inflammatory skin disease characterized by intensely pruritic, hyperkeratotic nodules distributed on the trunk and extensor surfaces of the extremities. PN has a profoundly negative impact on sleep and quality of life in patients with PN. There are currently no U.S. Food and Drug Administration-approved agents and patients are often recalcitrant to current therapies, highlighting the importance of further research into this severely debilitating condition. Areas covered: A PubMed search was conducted to find available literature on the pathophysiology and clinical management of PN. In this review article, we discuss the current understanding of the pathophysiology, recommended diagnostic approach, and treatment options available for PN. Expert opinion/commentary: PN is an extremely difficult condition to treat, because there is a lack of effective therapies available due to our limited understanding of its pathophysiology. Currently, available treatment options are often multimodal due to the intersection of neuroimmune etiologic factors in the pathogenesis of PN. Fortunately, as our knowledge of PN expands, novel treatments targeting specific molecular biomarkers of PN are emerging, providing hope to this long-suffering patient population.

Practical approaches for diagnosis and management of prurigo nodularis: United States expert panel consensus

BACKGROUND

Prurigo nodularis (PN) is a chronic disease characterized by intensely pruritic, raised, nodular lesions. Because there are currently no United States Food and Drug Administration-approved therapies specifically for PN, management is highly variable, and no consensus exists on treatment regimens.

OBJECTIVE

To provide practical guidance to help United States dermatologists diagnose and effectively treat patients with PN.

METHODS

We participated in a roundtable discussion to develop consensus recommendations on diagnosis and treatment of PN from a United States perspective.

RESULTS

The core findings in PN are the presence of firm, nodular lesions; pruritus lasting at least 6 weeks; and a history or signs, or both, of repeated scratching, picking, or rubbing. The diagnostic workup involves a complete review of systems, considering potential systemic diseases, and assessment of disease severity, including disease burden and pruritus intensity. Treatment should be selected based on a patient's clinical presentation, comorbidities, and response to prior treatments and should address both neural and immunologic components of pruritus.

LIMITATIONS

Data on PN are from anecdotal or small clinical trials, and all treatments are currently used off-label.

CONCLUSION

An effective treatment approach for patients with PN should be based on clinical judgment and tailored to the individual needs of the patient.