The role of β-blockers in dermatological treatment: a review

Therapeutic strategies focusing on immune dysregulation and neuroinflammation in rosacea

Rosacea is a complex inflammatory condition characterized by papulopustular lesions and erythema on the central face for which there is no cure. The development of rosacea is influenced by both external triggers and genetics, but the common pathophysiology is overactivation of the immune system. Here, we review the current data on proinflammatory cytokines and dysregulation of the neurovascular system as targetable components of rosacea. Amelioration of cutaneous and gastrointestinal dysbiosis and other external factors impacts the immune state and has been observed to improve rosacea. While multiple treatments exist, many patients do not achieve their goals for rosacea control and highlights an unmet need for dermatologic care. Current interventions encompass topical/oral drugs, light devices, and avoidance of triggers management. Additional understanding of the underlying pathogenesis may help us develop novel targeted therapeutic strategies to improve rosacea.

Exploring the Pathogenesis and Mechanism-Targeted Treatments of Rosacea: Previous Understanding and Updates

Rosacea is a chronic inflammatory skin disease characterized by recurrent erythema, flushing, telangiectasia, papules, pustules, and phymatous changes in the central area of the face. Patients with this condition often experience a significant negative impact on their quality of life, self-esteem, and overall well-being. Despite its prevalence, the pathogenesis of rosacea is not yet fully understood. Recent research advances are reshaping our understanding of the underlying mechanisms of rosacea, and treatment options based on the pathophysiological perspective hold promise to improve patient outcomes and reduce incidence. In this comprehensive review, we investigate the pathogenesis of rosacea in depth, with a focus on emerging and novel mechanisms, and provide an up-to-date overview of therapeutic strategies that target the diverse pathogenic mechanisms of rosacea. Lastly, we discuss potential future research directions aimed at enhancing our understanding of the condition and developing effective treatments.

The Role of Systemic and Topical Beta-Blockers in Dermatology: A Systematic Review

INTRODUCTION

Beta-blockers are proven to be safe and cost-effective agents in treating multiple dermatological conditions, which is why they are considered as an interesting and good alternative therapeutic agent by dermatologists. To our knowledge, there has been no comprehensive systematic review to date summarizing the role of both systemic and topical beta-blockers in dermatology.

METHODS

In this systematic review, we aim to review recent and relevant published literature in order to provide a comprehensive evidence-based summary to inform dermatologists.

RESULTS

An electronic-based literature search was carried out during October-December 2021 in the databases PubMed (MEDLINE), SCOPUS (EMBASE), and Cochrane Library. Furthermore, bibliographic sources were also reviewed for the selected articles. We followed The Preferred Reporting Items for Systematic Reviews and Meta-analyses 2020 (PRISMA) guidelines. We reviewed published literature about the role of beta-blockers in dermatology for the time period (January 2016 to December 2021).

CONCLUSIONS

A total of 126 publications were retrieved from different databases, of which 59 studies were finally included in our review after excluding non-eligible literature in accordance with our inclusion and exclusion criteria. The included articles consisted of meta-analyses, systematic reviews, clinical trials, retrospective and prospective cohort studies, case-control studies, case series, and case reports. In general, data in reviewed literature showed that both systemic and topical beta-blockers were reliable and safe therapeutic options in treating different dermatoses. Their effect has been studied as a mono-therapy, also as an adjuvant therapy combined with other current disease-specific therapeutic modalities such as lasers, radiation, chemotherapy, corticosteroids, or other beta-blockers options. Local and systemic adverse effects were mainly minor and non-significant.

Efficacy and Safety of Topical Timolol for the Treatment of Facial Angiofibroma in Children with Tuberous Sclerosis Complex

Objective

This study aimed to assess the efficacy and safety of topical timolol in treating facial angiofibromas (FAs) in pediatric patients with tuberous sclerosis complex (TSC).

Methods

A prospective clinical trial was conducted involving 15 children diagnosed with TSC and presenting with FAs. The participants were administered topical timolol gel 0.5% twice daily. Prior to the intervention, the severity of FAs in each patient was evaluated using the FA severity index (FASI), which assessed erythema, size, and extent of lesions. Clinical response was assessed at weeks 2 and 4 during the intervention period as well as 1 month after discontinuation of treatment.

Findings

Four weeks after discontinuing topical timolol 0.5%, statistically significant reductions were observed in the mean FASI score, erythema, size, and extent of lesions (P < 0.0001, P < 0.0001, P = 0.012, P = 0.008, respectively). FASI scores at 4 and 12 weeks postintervention, as well as 4 weeks after treatment cessation, demonstrated a significant decrease compared to baseline (P < 0.001). Erythema and extension scores also exhibited a significant decrease 1 month after treatment cessation compared to baseline (P < 0.05), while the mean size of lesions before and after the intervention did not show a statistically significant difference (P = 0.004).

Conclusion

Topical timolol 0.5% represents a cost-effective and readily available treatment option for pediatric patients with FAs associated with tuberous sclerosis.

Uses of eye drops in dermatology, literature review

Background: Since medication absorption through the skin and eye tissue seems similar, commercially available eye-drops could be used to treat skin diseases when topical therapies are unavailable or unaffordable. The FDA-approved and off-label applications of various eye drops used as topical treatments in dermatological clinical practice were highlighted in this review.Methodology: A thorough PubMed and Google Scholar library search using various combinations of the keywords (Eye drop, ocular solution, conjunctival installation, and skin diseases, topical, local, beta-blockers, prostaglandin, cyclosporin, apraclonidine, atropine, oxymetazoline).Results and conclusions: Based on the findings of the studies reviewed, timolol is highly recommended for infantile hemangioma and other vascular skin conditions such as angiomas, Kaposi sarcoma, acne, rosacea, and wound healing. Bimatoprost is a drug that can be used to treat hypotrichosis of any kind, as well as mild localized alopecia areata and leukoderma. Oxymetazoline ispromising for treating facial erythema. We recommend apraclonidine for mild upper eyelid ptosis induced botulinum neurotoxin. We don't recommend atropine for hyperhidrosis, although it can help with hydrocystomas and pruritis produced by syringomas. Tobramycin will need to be tested in RCTs before it can be confirmed as a viable alternative to systemic treatments for treating green nail syndrome.

Topical timolol in dermatology: infantile hemangiomas and beyond

Timolol, a non-selective β-adrenergic receptor blocker, is well-tolerated and is becoming increasingly popular in dermatology especially after its use in the management of infantile hemangiomas. Its effects are mainly due to vasoconstriction, inhibition of angiogenesis and keratinocyte migration promotion for re-epithelialization and wound healing. We review the evidence behind the use of timolol in several dermatological conditions including infantile hemangiomas, pyogenic granulomas, Kaposi's sarcoma, chronic wound healing, post-surgical wounds, acne vulgaris, rosacea, eczema and red scrotum syndrome.

Alpha and beta adrenergic receptors modulate keratinocyte migration

Keratinocyte migration into skin wounds is the step of the healing process that correlates with the wound closure rate. Keratinocyte migration, and wound epithelialization are decreased when beta 2-adrenergic receptors (B2AR) are activated by 1 μM epinephrine/adrenaline, resulting in delayed wound healing in human and mouse skin. In the present study, we found paradoxically, that in a subset of keratinocyte strains exposure to low concentrations of epinephrine (0.1 nM) increased, rather than decreased, their migratory rate. We find that both the alpha- and the beta-adrenergic receptors are expressed in human keratinocytes, and expression of alpha-2 AR subtypes demonstrated for the first time. Therefore, we tested if the alpha-AR could be modulating the increased migratory response observed in these cell strains. By using specific inhibitors to alpha-AR, we demonstrated that blocking A2B-AR could reverse the rapid cell migration induced by the 0.1 nM epinephrine. Phosphorylation of ERK was elevated after 1-10 minutes of the low epinephrine treatment and the A2B-AR inhibitor blocked the ERK phosphorylation. The results suggest that both the A2B-AR and B2AR mediate keratinocyte migration, in which with a low level of epinephrine treatment, A2B-AR could alter the B2AR signals and regulate the migration rate.

Repurposing Ophthalmologic Timolol for Dermatologic Use: Caveats and Historical Review of Adverse Events

Ophthalmic timolol solution is increasingly being repurposed as a topical therapeutic for a variety of dermatologic diseases, including pyogenic granulomas, infantile hemangiomas, and chronic wounds. There are no published guidelines or protocols for use in these indications in adults, and the dermatologic community may not be familiar with adverse events that have been extensively documented relating to its ophthalmic use. We review the evidence available relating to adverse events to topical timolol use to evaluate its safety in dermatologic applications and to alert clinicians to screening and monitoring that is needed when repurposing this drug for dermatologic use. The majority of serious adverse events associated with ophthalmic timolol were reported in the first 7 years of use, between 1978 and 1985, of which most common were cardiovascular and respiratory events, but also included 32 deaths. The available evidence suggests that ophthalmic timolol safety profiling may have been incomplete prior to widespread use. Recent clinical trials for dermatologic indications have focused on documenting efficacy and have not had rigorous monitoring for potential adverse events. Topical timolol may be safe and effective for the treatment of various dermatologic conditions in patients whose medical histories have been carefully reviewed for evidence of pre-existing cardiac or pulmonary disease and are monitored for potential adverse events. Despite the wide use of timolol in ophthalmologic practice, safe dermatologic repurposing requires recognition of the potential for facilitated systemic absorption though the skin and appreciation of its history of adverse events.

Rosacea Treatment: Review and Update

Rosacea is a chronic and inflammatory skin disease characterized by flushing, nontransient erythema, papules/pustules, telangiectasia, and phymatous changes. Secondary manifestations, such as itching, burning, or stinging, are often observed in patients with rosacea. In 2017, a phenotype-based approach for diagnosis and classification was recommended. With the update of the diagnosis and classification of rosacea, treatment options for patients with rosacea have attracted the attention of dermatologists. Here, we summarize the latest advances in rosacea treatment, including skin care and cosmetic treatments, topical therapies, oral therapies, laser- and light-based therapies, injection therapies, treatments for specific types of rosacea, treatments for systemic comorbidities, and combination therapies. The impact of the phenotype-based approach on rosacea treatment and future directions are also discussed.

Absorption and Safety of Topically Applied Timolol for Treatment of Chronic Cutaneous Wounds

Objective: There are no safety or absorption studies to guide topical timolol therapy for treatment of chronic wounds. This study was undertaken to address this gap. Approach: A prospective, observational, cross-sectional comparative study of timolol plasma levels in patients after topical administration to a chronic wound, compared with levels in patients after timolol ocular administration for the indication of glaucoma. Results: There was no statistically significant difference in the average plasma level of timolol in wound as compared with glaucoma patients. No bradycardia or wheezing was observed after administration. Innovation: We determined the single time point concentration of timolol in plasma 1 h after application of timolol 0.5% gel-forming solution to debrided chronic wounds, providing insight as to the safety of this emerging off-label treatment. Conclusion: The topical application of timolol for chronic wounds shares the same safety profile as the widely used application of ocular administration for glaucoma.

The Role of β-Blockers in Melanoma

Melanoma is one of the most aggressive and less chemotherapy-responsive human cancers, representing a major public health issue worldwide. The early diagnosis still represents the best approach in order to reduce mortality, especially in advanced stages. Preclinical evidence, collected through several in vitro and in vivo models, has been accumulating about the pathophysiological involvement of β-adrenoceptors in melanoma progression. This involvement has been paralleled by the evidence that drugs blocking β-adrenoceptors (β-blockers) may have a relevant role in the treatment of melanoma and in the prevention of its progression. β-blockers are a class of drugs extensively used in clinical practice, not limited to cardiovascular therapeutics. Evidence collected through retrospective and prospective observational studies suggests that treatment with β-blockers, mainly propranolol, is able to delay melanoma progression. Although conclusive evidence is still lacking, current knowledge proposes β-blockers as an opportunity for antitumor treatment in melanoma. Clinical trials are needed in order to prove their claimed efficacy. Graphical Abstract.

Immunologic adverse reactions of β-blockers and the skin

β-Blockers are a widely utilised class of medication. They have been in use for a variety of systemic disorders including hypertension, heart failure and intention tremors. Their use in dermatology has garnered growing interest with the discovery of their therapeutic effects in the treatment of haemangiomas, their potential positive effects in wound healing, Kaposi sarcoma, melanoma and pyogenic granuloma, and, more recently, pemphigus. Since β-blockers are deployed in a variety of disorders, which have cutaneous co-morbidities such as psoriasis, their pertinence to dermatologists cannot be overstated. Likewise, β-blockers, like any other drug category, carry risks of side effects, some of which are dermatologic. These include triggering and exacerbation of psoriasis, psoriatic and rheumatoid arthritis, anaphylaxis, contact dermatitis, occupational contact dermatitis, Raynaud's disease, alopecia, lichen planus-like drug eruption, hyperhydrosis and vitiligo. While recent articles have focussed on the positive uses of β-blockers, it may also be wise to call our attention to the potential dermatologic adverse effects that may follow β-blocker use, as well as possible therapeutic approaches to these. This short review will focus on those dermatoses resulting from β-blocker use, which have an immunologic basis.

Angiographic optical coherence tomography imaging of hemangiomas and port wine birthmarks

OBJECTIVES

A current therapeutic challenge of vascular lesions is that they do not always respond effectively to laser treatment. Information on targeted vessels could potentially be used to guide laser treatments. Optical coherence tomography (OCT) is a useful tool for the non-invasive imaging of tissues, including skin hemangiomas and port wine birthmarks. Dynamic OCT is able to rapidly characterize cutaneous blood vessels. The primary goal of this study was to demonstrate the ability of bedside OCT to image (i) overall vessel pattern; (ii) individual vessel morphology, diameter and depth; and (iii) total vessel density as a function of depth in infantile hemangiomas and port wine birthmarks (PWB).

MATERIALS AND METHODS

This IRB approved, observational clinical trial was performed among healthy volunteers ages 3 months-73 years old. All patients presented for laser treatment of either infantile hemangiomas or PWB with skin types ranging from Fitzpatrick I-V. OCT imaging of 49 hemangioma and PWB scans were performed pre- and post-treatment. The diameter and depth of the blood vessels making up the vascular lesions were measured. In addition, normal skin was scanned for comparison. Five datasets for infantile hemangiomas and five for PWB that were without motion artifacts were analyzed.

RESULTS

Scanned lesions exhibited variable and highly heterogeneous blood vessel patterns with vessel diameters ranging from 20 to 160 μm, suggesting that the laser treatment with single pulse durations may not be optimal. The largest blood vessel diameter observed (160 μm) may not be adequately treated by commonly used pulsed dye laser pulse durations.

CONCLUSION

OCT allowed rapid, non-invasive characterization of the diameter and depth of blood vessels in individual vascular lesions. Imaged lesions consisted of a heterogeneous population of vessel sizes, morphologies, and depth. Future studies could utilize this information to assist development of individualized treatment protocols in an effort to improve vascular birthmark removal. Lasers Surg. Med. © 2018 Wiley Periodicals, Inc.