Serum 25-hydroxyvitamin D increases with NB-UVB and UVA/UVB phototherapy in patients with psoriasis and atopic dermatitis in Western Australia

Vitamin D Signaling in Psoriasis: Pathogenesis and Therapy

Psoriasis is a systemic, chronic, immune-mediated disease that affects approximately 2–3% of the world’s population. The etiology and pathophysiology of psoriasis are still unknown, but the activation of the adaptive immune system with the main role of T-cells is key in psoriasis pathogenesis. The modulation of the local neuroendocrine system with the downregulation of pro-inflammatory and the upregulation of anti-inflammatory messengers represent a promising adjuvant treatment in psoriasis therapies. Vitamin D receptors and vitamin D-mediated signaling pathways function in the skin and are essential in maintaining the skin homeostasis. The active forms of vitamin D act as powerful immunomodulators of clinical response in psoriatic patients and represent the effective and safe adjuvant treatments for psoriasis, even when high doses of vitamin D are administered. The phototherapy of psoriasis, especially UVB-based, changes the serum level of 25(OH)D, but the correlation of 25(OH)D changes and psoriasis improvement need more clinical trials, since contradictory data have been published. Vitamin D derivatives can improve the efficacy of psoriasis phototherapy without inducing adverse side effects. The anti-psoriatic treatment could include non-calcemic CYP11A1-derived vitamin D hydroxyderivatives that would act on the VDR or as inverse agonists on RORs or activate alternative nuclear receptors including AhR and LXRs. In conclusion, vitamin D signaling can play an important role in the natural history of psoriasis. Selective targeting of proper nuclear receptors could represent potential treatment options in psoriasis.

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.

Ultraviolet radiation, vitamin D, and COVID-19

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has become pandemic on March 11^th, 2020. COVID-19 has a range of symptoms that includes fever, fatigue, dry cough, aches, and labored breathing to acute respiratory distress and possibly death. Health systems and hospitals have been completely rearranged since March 2020 in order to limit the high rate of virus spreading. Hence, a great debate on deferrable visits and treatments including phototherapy for skin diseases is developing. In particular, as regards phototherapy very few data are currently available regarding the chance to continue it, even if it may be a useful resource for treating numerous dermatological patients. However, phototherapy has an immunosuppressive action possibly facilitating virus infection. In the context of COVID-19 infection risk it is important to pointed out whether sunlight, phototherapy and in particular ultraviolet radiation (UV-R) constitute or not a risk for patients. In this review we aimed to focus on the relationship between UV-R, sunlight, phototherapy, and viral infections particularly focusing on COVID-19.

Shifts in the Skin Microbiota after UVB Treatment in Adult Atopic Dermatitis

BACKGROUND

The pathophysiology in atopic dermatitis (AD) is not fully understood, but immune dysfunction, skin barrier defects, and alterations of the skin microbiota are thought to play important roles. AD skin is frequently colonized with Staphylococcus aureus (S. aureus) and microbial diversity on lesional skin (LS) is reduced compared to on healthy skin. Treatment with narrow-band ultraviolet B (nb-UVB) leads to clinical improvement of the eczema and reduced abundance of S. aureus. However, in-depth knowledge of the temporal dynamics of the skin microbiota in AD in response to nb-UVB treatment is lacking and could provide important clues to decipher whether the microbial changes are primary drivers of the disease, or secondary to the inflammatory process.

OBJECTIVES

To map the temporal shifts in the microbiota of the skin, nose, and throat in adult AD patients after nb-UVB treatment.

METHODS

Skin swabs were taken from lesional AD skin (n = 16) before and after 3 treatments of nb-UVB, and after 6-8 weeks of full-body treatment. We also obtained samples from non-lesional skin (NLS) and from the nose and throat. All samples were characterized by 16S rRNA gene sequencing.

RESULTS

We observed shifts towards higher diversity in the microbiota of lesional AD skin after 6-8 weeks of treatment, while the microbiota of NLS and of the nose/throat remained unchanged. After only 3 treatments with nb-UVB, there were no significant changes in the microbiota.

CONCLUSION

Nb-UVB induces changes in the skin microbiota towards higher diversity, but the microbiota of the nose and throat are not altered.

Oral Vitamin D Therapy in Patients with Psoriasis

Vitamin D treatment is effective when applied topically to the skin for plaque-type psoriasis. Oral vitamin D supplementation might be effective as an adjuvant treatment option in psoriasis. This umbrella review aimed to highlight the current knowledge regarding the use of oral vitamin D for treatment of patients with psoriasis. We performed a literature search and identified 107 eligible full-text articles that were relevant to the research interest. Among these, 10 review articles were selected, and data were extracted. A data synthesis showed that only a few studies monitored oral vitamin D efficacy in patients with psoriasis. No studies investigated the optimal dose of systemic vitamin D in psoriasis. However, most studies did not observe side effects for doses within a relatively narrow range (0.25 to 2 μg/day). These results suggest that more large-scale studies are needed to determine the efficacy, optimal dose, and adverse effects of vitamin D administration in patients with psoriasis.

The relevance of serum vitamin D in psoriasis: a review

Observational research has identified low serum levels of 25-hydroxyvitamin D (25[OH]D) in many non-skeletal diseases. Whether this is causal or due to underlying illness is unknown. Low serum 25[OH]D levels are also reported in the general population. Observational and experimental studies identify that vitamin D supplementation may be beneficial in reducing all-cause mortality in elderly women, as well as cancer mortality. Our aim was to review the literature to identify the relevance of serum 25[OH]D levels in psoriasis. Forty-five studies were included in our analysis. Most of these studies identified low serum 25[OH]D levels in psoriasis patients. Evidence of causality is lacking. Treatment with phototherapy leads to an increase in serum 25[OH]D. There is little evidence that the increase in 25[OH]D after phototherapy correlates with improved disease severity. Multiple studies report an improvement in psoriasis with vitamin D supplementation. These data are predominantly from small observational or non-randomised interventional studies. Randomised controlled trials to date have had small numbers and short follow-up periods. The optimal dose of supplementation is unknown and dosing is not standardised across different studies. The definition of vitamin D insufficiency varies across studies. Low serum 25[OH]D levels may be associated with comorbidities in psoriasis patients, including metabolic syndrome and cardiovascular risk. Evidence of causation is absent. Until further high-quality evidence is available, the relevance of low serum 25[OH]D levels in psoriasis patients is unknown, as is the benefit of supplementation on disease control. Supplementation in patients with low 25[OH]D is of benefit to those at risk of impaired bone health.