Conventional and Novel Treatment Modalities in Rosacea

Rosacea: Practical Guidance and Challenges for Clinical Management

Rosacea is a common chronic dermatosis. Clinically, rosacea can present with flushing, erythema, papules, pustules, telangiectasias, phymatous changes, pruritus, burning, and stinging. In 2017, the National Rosacea Society Expert Committee recommended a phenotype-based classification for therapy. In this review, we identify monotherapies and multimodal treatment approaches for the clinical management of rosacea including topical, systemic, laser and light, alternative, and combination therapies.

Rosacea pathogenesis and therapeutics: current treatments and a look at future targets

Rosacea is a chronic inflammatory skin condition associated with a significant health and economic burden from costs and loss of productivity due to seeking medical treatment. The disease encompasses multiple phenotypic manifestations involving a complex and multi-variate pathogenesis. Although the pathophysiology of rosacea is not completely understood, ongoing research is continually elucidating its mechanisms. In this review, current concepts of rosacea pathogenesis will be addressed which involve skin barrier and permeability dysfunction, the innate and adaptive immune systems, and the neurovascular system. More specifically, the cathelicidin pathway, transient potential receptor channels, mast cells, and the NLRP3 inflammasome pathway are various targets of current pharmacologic regimens. Future therapies may seek different mechanisms to act on current treatment targets, like the potential use of JAK/STAT inhibitors in ameliorating skin barrier dysfunction or TLR antagonists in alleviating cathelicidin mediated inflammation. Other potential treatments aim for entirely different molecular targets such as microvesicle particle mediated local and systemic inflammation. Ultimately rosacea is associated with a significant health and economic burden which warrants deeper research into its pathogenesis and resultant new treatment discovery.

The Efficacy and Safety of Botulinum Toxin A for the Treatment of Rosacea: A Systematic Review

The off-label use of botulinum toxin type-A (BoNT-A) in treating rosacea seems encouraging, but the evidence is still lacking regarding its efficacy and safety. This study was conducted to summarize the evidence regarding the efficacy and safety of BoNT-A in the treatment of rosacea patients. A comprehensive literature search was conducted in several databases, and 17 studies were included. Before-after and split-face comparisons showed that BoNT-A significantly alleviated the symptoms of facial erythema and flushing and improved the patient's quality of life/satisfaction. However, the symptoms recurred three to six months post-injection, requiring repeated treatments in some patients. The pooled rates of post-injection localized erythema, ecchymosis, and facial muscle affection represented 24.6%, 5.1%, and 4.3%, respectively. BoNT-A seems to be effective in alleviating the symptoms of rosacea with a low rate of adverse events. However, the recurrence of the symptoms a few months after the injection requires repeated sessions, which may raise cost-effectiveness issues. Large-scale clinical trials are required to confirm the effectiveness and define the optimal dosing regimen and the rate of recurrence. Future studies should allow for an adequate follow-up after the treatment, with repeated measurements of the outcomes.

Elucidating the potential pharmaceutical mechanism of Gyejibokryeong-hwan on rosacea using network analysis

Rosacea is a chronic erythematous disease with telangiectasia that affects the central area of the face. However, because of the ambiguity in the pathophysiology of rosacea, its treatment has not been clearly elucidated; therefore, new therapeutic options need to be developed. Gyejibokryeong-hwan (GBH) is widely used in clinical practice for various blood circulation disorders, including hot flushes. Therefore, we explored the potential pharmaceutical mechanism of GBH on rosacea and investigated the therapeutic points exclusive to GBH through comparative analysis with chemical drugs recommended in 4 guidelines for rosacea based on network analysis. The active compounds in GBH were identified, and the proteins targeted by these compounds and the genes related to rosacea were searched. Additionally, the proteins targeted by the guideline drugs were also searched to compare their effects. And the pathway/term analysis of common genes was conducted. Ten active compounds were obtained for rosacea. There were 14 rosacea-related genes targeted by GBH, with VEGFA, TNF, and IL-4, which were suggested as core genes. The pathway/term analysis of the 14 common genes revealed that GBH could potentially act on rosacea via 2 pathways: the "interleukin 17 signaling pathway" and the "neuroinflammatory response." Comparison and analysis of the protein targets between GBH and guideline drugs revealed that only GBH separately acts on the "vascular wound healing pathway." GBH has the potential to act on IL-17 signaling pathway, neuroinflammatory response and vascular wound healing pathway. Further studies are needed to determine the potential mechanism of GBH in rosacea.

Clinical translation of choline and geranic acid deep eutectic solvent

Choline geranate deep eutectic solvent/ionic liquid (CAGE) has shown several desirable therapeutic properties including antimicrobial activity and ability to deliver drugs transdermally in research laboratories. Here, we describe the first report of clinical translation of CAGE from the lab into the clinic for the treatment of rosacea, a common chronic inflammatory skin disorder that affects the face. We describe the seven steps of clinical translation including (a) scale-up, (b) characterization, (c) stability analysis, (d) mechanism of action, (e) dose determination, (f) GLP toxicity study, and (g) human clinical study. We describe the challenges and outcomes in these steps, especially those that uniquely arise from the deep eutectic nature of CAGE. Our translational efforts led to a 12-week open-label phase 1b cosmetic study with CAGE1:2 gel (CGB400) in mild-moderate facial rosacea in 26 patients where CGB400 exhibited a marked reduction in the number of inflammatory lesions. These results demonstrate the therapeutic potential of CGB400 for treating rosacea as well as it provides insights into the translational journey of deep eutectic solvents, in particular CAGE, for dermatological applications.

Use of Botulinum Toxin in Treating Rosacea: A Systematic Review

Background

Rosacea is a chronic skin disorder characterized by erythema, flushing, telangiectasia, papules and pustules, phymatous changes, and ocular involvement. The aim of this study was to examine all published research articles in which botulinum toxin was used to treat rosacea and to evaluate the efficacy and safety of this treatment.

Methods

PubMed, Embase, Cochrane Library, and Web of Science database were used to identify articles eligible for systematic review on March 26, 2021. Prospective or retrospective studies which directly used botulinum toxin to treat rosacea were included and reviewed.

Results

Nine studies were included in this systematic review. Two were randomized controlled trials, graded as Level 2 for the quality of evidence. The total number of participants was 130, and the number of participants in each study ranged from 1 to 25. The improvement was observed in all studies in signs and symptoms compared with baseline. Adverse events were transitory and self-limited.

Conclusion

Botulinum toxin could have overall satisfying efficacy and safety in the treatment of rosacea, though limited by small sample size, imperfect study design, and short follow-up visits.

Protecting the outside: biological tools to manipulate the skin microbiota

Interest surrounding the role that skin microbes play in various aspects of human health has recently experienced a timely surge, particularly among researchers, clinicians and consumer-focused industries. The world is now approaching a post-antibiotic era where conventional antibacterial therapeutics have shown a loss in effectiveness due to overuse, leading to the looming antibiotic resistance crisis. The increasing threat posed by antibiotic resistance is compounded by an inadequate discovery rate of new antibiotics and has, in turn, resulted in global interest for alternative solutions. Recent studies have demonstrated that imbalances in skin microbiota are associated with assorted skin diseases and infections. Specifically, restoration of this ecosystem imbalance results in an alleviation of symptoms, achieved simply by applying bacteria normally found in abundance on healthy skin to the skin of those deficient in beneficial bacteria. The aim of this review is to discuss the currently available literature on biological tools that have the potential to manipulate the skin microbiota, with particular focus on bacteriocins, phage therapy, antibiotics, probiotics and targets of the gut-skin axis. This review will also address how the skin microbiota protects humans from invading pathogens in the external environment while discussing novel strategies to manipulate the skin microbiota to avoid and/or treat various disease states.