Updates on the Molecular Basis of Photoaging in All Skin Types

Photoaging is a complex, ongoing process that clinically manifests as cutaneous rhytides, atrophy, laxity, dyspigmentation, telangiectasias, roughness, and mottled appearance of the skin. There is an abundance of research establishing the mechanism of ultraviolet (UV) - induced photodamage as it is a significant source of photoaging and skin cancers. While UV damage is known to induce photoaging, it is important to understand how other forms of light radiation also contribute to this process. UV only constitutes 5 to 10% of solar radiation that reaches the earth's surface. The remaining nearly 90% is evenly split between infrared and visible light radiation. Early research shows that varied skin types may elicit different photobiologic responses to light. This article presents the mechanisms and biomarkers of photodamage induced by light from across the spectrum, including UV, visible light, and infrared to better prevent and reverse the damage of photoaging in all skin types.J Drugs Dermatol. 2024;23(7):504-509.  doi:10.36849/JDD.7438.

Systematic review of topical, laser, and oral treatments in acanthosis nigricans clinical trials

Acanthosis nigricans (AN), with an estimated prevalence of 19.4% in the U.S., presents as hyperpigmented, velvety plaques in intertriginous regions. Acanthosis Nigricans negatively affects psychological well-being and particularly impacts skin of color individuals. Addressing the underlying cause of acanthosis nigricans, as current guidelines recommend, is often challenging. This highlights the importance of skin directed treatment for acanthosis nigricans. This systematic review evaluated topical, laser, and oral treatments for acanthosis nigricans and provides evidence-based recommendations for clinical use. Adhering to PRISMA guidelines, we evaluated 19 clinical trials investigating topical, oral, and laser interventions for acanthosis nigricans. Oxford Centre for Evidence-Based Medicine guidelines were used to make clinical recommendations. We strongly recommend topical tretinoin (grade A) and endorse the appropriate use of adapalene gel, urea cream, and fractional carbon dioxide laser therapy (grade B). Further research is essential to enhance our understanding of alternative treatments to determine additional evidence-based recommendations. This review aims to guide clinicians in managing acanthosis nigricans, especially when direct treatment of underlying conditions is impractical.

Investigating the Relationship Between Acne and Vasodilatory Medications in a Hospital-Wide Adult Population

Acne vulgaris is a common chronic dermatological condition characterized by obstruction and inflammation of pilosebaceous units. Recent research on a different dermatologic condition has demonstrated that the use of vasodilatory medications is associated with a decreased relative risk of rosacea. This finding is significant due to the overlapping inflammatory pathways involved in rosacea and acne. Herein, a retrospective cohort study was designed to determine the correlation between vasodilator usage and the risk of developing acne within 5 years, contrasting it with thiazide diuretics, chosen as a control due to its non-vasodilatory antihypertensive mechanism and availability of data. Angiotensin-converting enzyme (ACE) inhibitors (RR, 0.775; 95% CI, 0.727-0.826; P<0.05), angiotensin receptor blockers (ARBs) (RR, 0.739; 95% CI, 0.685-0.797; P<0.05), beta-blockers (BB) (RR, 0.829; 95% CI, 0.777-0.885; P<0.05), and calcium channel blockers (CCB) usage (RR, 0.821, 95% CI, 0.773-0.873; P<0.05) were associated with a significantly lower risk of developing acne within 5 years of initiating therapy compared to thiazide diuretics. It is unclear if thiazide diuretics are more likely to cause acne within the adult population or if vasodilators are protective against the development of acne. Finding mechanisms and therapeutics that lower the risk of developing acne is of significant public health interest, and this study provides a step toward this endeavor. Further research is required to uncover the underlying mechanisms for this reduction in the development of acne.  J Drugs Dermatol. 2024;23(6):446-449.     doi:10.36849/JDD.8362.

Blue light aminolevulinic acid photodynamic therapy downregulates cell division and proliferation pathways in cutaneous squamous cell carcinoma

5-Aminolevulinic acid (5-ALA) photodynamic therapy (PDT) is a treatment for actinic keratosis (AK) and has been studied as a treatment for noninvasive cutaneous squamous cell carcinoma (cSCC). PDT induces apoptosis and necrosis in AKs and cSCC. 5-ALA blue light PDT may modulate gene expression and pathways in surviving cells. In this study, differential gene expression and pathway analysis of cSCC and human dermal fibroblasts were compared before and after 5-ALA blue light PDT using RNA sequencing. No genes were differentially expressed after correcting for multiple testing (false discovery rate < 0.05). As a result, transcription factor, gene enrichment, and pathway analysis were performed with genes identified before multiple testing (p < 0.05). Pathways associated with proliferation and carcinogenesis were downregulated. These findings using 5-ALA blue light PDT are similar to previously published studies using methyl-aminolevulinic and red light protocols, indicating that surviving residual cells may undergo changes consistent with a less aggressive cancerous phenotype.

Systematic review of randomized controlled trials of topicals for actinic keratosis field therapy

Cutaneous field cancerization in dermatology describes the anatomic region of photodamaged skin with actinic keratoses (AKs) or cutaneous squamous cell carcinoma (cSCC) that is surrounded by cellular atypia, forming a dysplastic field. The concept of field cancerization is especially relevant in dermatology, as actinic keratoses and the surrounding dysplastic region can progress to carcinomas, necessitating the treatment of the field. Recent research has focused on field-directed therapy using topical agents. This study aims to systematically review randomized controlled trials on topical treatments for actinic keratosis field cancerization, following the PRISMA guidelines. Clinical recommendations were based on the Oxford Centre for Evidence-Based Medicine. We identified 20 original randomized controlled trials for topical cutaneous field therapy. 0.5% 5-Fluorouracil/salicylic acid and 0.5% 5-fluorouracil received a clinical recommendation grade of A, while diclofenac sodium received a clinical recommendation grade of B. Calcipotriol/5-fluorouracil, Imiquimod, sunscreen combination therapies, and tirbanibulin received a recommendation grade of C. This review provides a framework for clinicians when considering topical treatments for patients with field cancerization.

Near-infrared light does not induce DNA damage in human dermal fibroblasts

Photobiomodulation (PBM) can be used to treat a range of conditions in dermatology. PBM refers to the changes induced by red (RL, 620-700 nm) and near-infrared (NIR, 700-1440 nm) light. Light radiation-induced DNA damage is a major contributor to aging and skin cancer. It is crucial to study the effects of PBM on DNA to ensure safety. Our lab previously demonstrated that RL (633 ± 6 nm) did not result in human dermal fibroblasts (HDFs) DNA damage. This study employed similar methods to investigate NIR effects. Commercially available LED-NIR (830 ± 5 nm) panels (66, 132, and 264 J/cm2 ) did not result in DNA damage measured by cyclobutane pyrimidine dimers and pyrimidine-6,4-pyrimidone photoproducts in HDFs compared to temperature-matched controls immediately, 3 h, and 24 h following irradiation and compared to positive and negative controls. This demonstrates that LED-NIR does not damage DNA in HDFs in vitro.

Male facial rejuvenation using a combination 633, 830, and 1072 nm LED face mask

Home-based photobiomodulation is a popular treatment modality for patients seeking non-invasive aesthetic treatment. Studies demonstrate that photobiomodulation is effective for skin rejuvenation, which is aimed at improving the overall appearance of the skin by reducing fine lines and wrinkles and improving skin texture, skin tone, and dyspigmentation. Most current skin rejuvenation research focuses on treatments in women. However, men's aesthetics remains an underserved market. A combined red light (RL) and near-infrared (NIR) light-emitting diode (LED) has been designed specifically to target male skin, which may have different physiological and biophysical properties compared to female skin. Herein, the safety and efficacy of a commercially available RL and NIR (633, 830, and 1072 nm) LED array designed to be worn as a face mask was assessed. Primary outcomes included adverse events and facial rejuvenation as determined by participant-reported satisfaction scales and quantitative digital skin photography and computer analysis after 6 weeks of treatment. The participants reported overall favorable results and improvements in all individual categories, were satisfied with the treatment, and would recommend the product to others. The participants perceived the greatest improvement in fine lines and wrinkles, skin texture, and youthful appearance. Photographic digital analysis demonstrated favorable improvements in wrinkles, UV spots, brown spots, pores, and porphyrins. These results support the use of RL and NIR to treat male skin. Advantages of the LED facemask include its safety, efficacy, convenient home-based use, minimal associated downtime, simple operation, non-invasiveness, and appreciable results in as few as 6 weeks.

The Association Between Herpes Simplex Virus and Alzheimer's Disease: A Systematic Review

Alzheimer's disease (AD) is a significant public health concern, affecting more than 6 million Americans; and currently, there are no cure or effective treatment options. The underlying etiology and pathogenesis are not fully understood, presenting a barrier to therapy. A substantial amount of data exists associating infection with Herpes simplex virus 1 (HSV-1) and AD. This review of published studies highlights the epidemiological associations between HSV-1 and AD. A systematic search of PubMed, Embase, and Web of Science was conducted on January 6, 2022, using PRISMA guidelines. Articles that presented epidemiological data correlating HSV-1 with AD were included. Bibliographies were screened for additional relevant articles as well. After review, 21 studies were included: 2 review articles and 19 population-based studies including case control, cohort, and cross-sectional studies.  The quantitative data derived from the studies in this report substantiate a relationship between infection with HSV-1 and AD. Based on these results, it may be of reasonable benefit to more consistently treat latent or active HSV-1 infection with anti-viral medications to potentially reduce the risk of AD. Furthermore, a prospective randomized controlled clinical trial could elucidate the benefit of anti-viral therapy to prevent or limit AD.J Drugs Dermatol. 2023;22(10):1046-1052     doi:10.36849/JDD.6785.

Cutaneous effects of photobiomodulation with 1072 nm light

Photobiomodulation, also known as low-level light therapy, has gained popularity in treating a variety of dermatologic and non-dermatologic conditions. The near-infrared (NIR) portion ranging from 700 to 1440 nm has a broad spectrum but most current research focuses on relatively shorter wavelengths. To date, clinical research regarding the application of 1072 NIR is limited to treatments for infections and photorejuvenation treatment in females. However, 1072 NIR light therapy may benefit male patients. This theoretical application is based on the biological properties of this subgroup having increased cutaneous density and thickness and the physical properties of 1072 NIR allowing it to penetrate increased depth. 1072 NIR can reach more cells throughout the epidermis and dermis compared to other parts of the electromagnetic spectrum traditionally used in phototherapy to provide unique and targeted benefits. 1072 NIR light-emitting diodes are commercially available and therefore hold tremendous potential to become accessible, affordable treatment options. Given the increased demand and market size for aesthetics for men that remains untapped, there is opportunity for future research to elucidate the potential for this wavelength as a safe and effective treatment.

Predictors of Dairy Worker Pre-Test and Post-Test Performance on a Dairy Safety Knowledge Test: Impact of Education Level and Native Language

BACKGROUND

Efficacy-driven assessments of linguistically appropriate occupational health and safety training (OHS) for dairy workers remain uncommon. This study analyzes predictors of performance on a dairy safety knowledge test using pre-and-post knowledge assessments. The safety training course was delivered by iPad™ to Idahoan dairy workers, managers, and owners.

OBJECTIVE

To determine the predictors of safety knowledge scores among dairy worker course participants.

METHODS

Predictors of pre-test (baseline) scores and change in test scores of n = 1,336 participants were compared, and multivariate iterative linear regressions were used to predict test performance, adjusting for variables such as occupation, years of formal education, native language, and years in dairy work.

RESULTS

Test scores for Spanish and English speakers improved between pre-test and post-test. Years of formal education was the most predictive variable of higher baseline scores and change in test scores among dairy safety course participants, regardless of language.

CONCLUSION

Dairy worker safety training course results showed improvements in safety knowledge and test scores. Years of formal education of participants appears to be a key determinant of increases in safety knowledge, and therefore safety training programs need to address the learning needs of less educated workers.

Visible red light does not induce DNA damage in human dermal fibroblasts

Visible red light (RL) therapy is a rapidly expanding treatment option for dermatological conditions, including acne, psoriasis and chronic wounds. It is currently unknown if high fluences of RL induce DNA damage via reactive oxygen species (ROS) stress or other pathways. Our lab previously demonstrated that RL generates ROS in human dermal fibroblasts (HDFs). Other studies show that UV and blue light generate ROS and DNA damage in fibroblasts. This study aims to determine if RL induces DNA damage in HDFs. We found that 320 J/cm² , 640 J/cm² and 1280 J/cm² RL (633 ± 6 nm) did not measurably increase DNA damage in the form of cyclobutane pyrimidine dimers (CPD) or 6-4 photoproducts (6-4PP) immediately, 3 hours and 24 hours following irradiation. Our study further supports that RL therapy is safe in human skin fibroblasts.

Red Light Phototherapy Using Light-Emitting Diodes Inhibits Melanoma Proliferation and Alters Tumor Microenvironments

Background

Total annual cancer rates have decreased due to improved treatment and prevention. However, the incidence of melanoma is rising, and not all patients respond to immune and targeted approaches. Therefore, we sought to determine the efficacy of red light (RL) phototherapy in preclinical models of melanoma.

Methods

Melanoma cells (A375, B16F10, MNT-1) were irradiated with RL. Melanoma proliferation, apoptosis, oxidative stress, and p53 phosphorylation were measured in vitro. In C57BL/6 mice, phototherapy safety, B16F10 tumor growth, and immunocyte infiltration were assessed following RL.

Results

In vitro, 640 J/cm² RL decreased cellular proliferation without increasing apoptosis, while 1280 J/cm² increased apoptosis. RL increased intracellular reactive oxygen species generation and p53 phosphorylation. In animal models, 2560 J/cm² RL significantly prevented melanoma growth and increased the expression of CD103+ dendritic cells. 1280 and 1920 J/cm² RL decreased tumor volume, but not significantly. RL did not cause skin inflammation or erythema in normal skin.

Conclusion

RL represents a potentially safe and effective melanoma therapeutic. RL prevented tumor growth and increased the expression of immune markers, such as CD103, that are associated with favorable melanoma outcomes. Further research is needed to determine the optimal clinical treatment regimen for melanoma using RL.

The scope for adaptive capacity in emergency departments: modelling performance constraints using control task analysis and social organisational cooperation analysis

Patient flow between the emergency department (ED) and hospital wards becomes problematic when bed availability is limited. To better understand the constraints that shape patient flow and everyday work in the ED, we applied Control Task Analysis (i.e. Contextual Activities Template, CAT) and Social Organisational Cooperation Analysis (SOCA) phases from the Cognitive Work Analysis framework to identify ways in which to optimise patient flow. The model and analysis were created through observations in the ED of clinicians (e.g. nurses, doctors), and professional staff (e.g. ward personnel, clerks). The CAT and SOCA-CAT models illustrate workspaces, patient journey phases, and patient volume within the department that are heavily loaded with tasks and human and non-human agents performing these tasks, while others are underutilised. The findings suggest that an ED's adaptive capacity could be strengthened through the integration of additional human and non-human agents allowing the redistribution of clinical and non-clinical tasks. Practitioner Summary: Workflow in EDs is constrained by uneven geographical distribution of activities, insufficient adaptive support during critical patient journey phases and periods of high patient volume. Adaptive capacity could be strengthened by additional human and non-human agents in combination with a redistribution of tasks, supporting seamless successful structural and behavioural adaptation in ED.

Symptom Resolution and Recurrent Urinary Incontinence Following Removal of Painful Midurethral Slings

OBJECTIVE

To evaluate pain improvement and recurrent stress incontinence (SUI) following painful synthetic midurethral sling (MUS) removal.

METHODS

We conducted a retrospective review of patients who underwent synthetic MUS removal at our institution from 2009-2016 for the indication of pain. We recorded sling type (transobturator vs retropubic), complete vs partial removal, and presenting symptoms. Postoperative pain improvement was categorized as resolved (pain resolved, requiring no further therapy), improved (pain less bothersome, may require further therapy), or unresolved (no/minimal improvement, requiring further management). Recurrent incontinence and further reconstructive procedures were assessed.

RESULTS

87 patients (49 complete and 38 partial removal) with pain as the primary indication for removal were included. Median age at intervention was 54 years with median follow-up of 8 months. Overall, pain improved or resolved in 78.1% of cases. Complete removal was associated with significantly greater percentage of pain resolution (63.3%) compared to partial removal (26.3%) (P = 0.002) regardless of sling type. No significant differences in recurrent SUI were noted in complete vs partial removal. Additional reconstructive procedures were performed in 28 patients, most commonly sling placement, with no significant difference in complete (20.4%) vs partial (28.9%) removal groups (P = 0.36). The overall complication rate was low (5.7%), a majority of which were transfusions (4.6%).

CONCLUSION

Following MUS removal, most patients experienced resolution or improvement of pain. Complete sling removal was associated with significantly greater percentage of pain resolution compared to partial removal in both retropubic and transobturator slings. Rates of recurrent SUI and reintervention for SUI were not related to the extent of sling removal.

Transcriptome analysis of human dermal fibroblasts following red light phototherapy

Fibrosis occurs when collagen deposition and fibroblast proliferation replace healthy tissue. Red light (RL) may improve skin fibrosis via photobiomodulation, the process by which photosensitive chromophores in cells absorb visible or near-infrared light and undergo photophysical reactions. Our previous research demonstrated that high fluence RL reduces fibroblast proliferation, collagen deposition, and migration. Despite the identification of several cellular mechanisms underpinning RL phototherapy, little is known about the transcriptional changes that lead to anti-fibrotic cellular responses. Herein, RNA sequencing was performed on human dermal fibroblasts treated with RL phototherapy. Pathway enrichment and transcription factor analysis revealed regulation of extracellular matrices, proliferation, and cellular responses to oxygen-containing compounds following RL phototherapy. Specifically, RL phototherapy increased the expression of MMP1, which codes for matrix metalloproteinase-1 (MMP-1) and is responsible for remodeling extracellular collagen. Differential regulation of MMP1 was confirmed with RT-qPCR and ELISA. Additionally, RL upregulated PRSS35, which has not been previously associated with skin activity, but has known anti-fibrotic functions. Our results suggest that RL may benefit patients by altering fibrotic gene expression.

Visible light. Part I: Properties and cutaneous effects of visible light

Approximately 50% of the sunlight reaching the Earth's surface is visible light (400-700 nm). Other sources of visible light include lasers, light-emitting diodes, and flash lamps. Photons from visible light are absorbed by photoreceptive chromophores (e.g., melanin, heme, and opsins), altering skin function by activating and imparting energy to chromophores. Additionally, visible light can penetrate the full thickness of the skin and induce pigmentation and erythema. Clinically, lasers and light devices are used to treat skin conditions by utilizing specific wavelengths and treatment parameters. Red and blue light from light-emitting diodes and intense pulsed light have been studied as antimicrobial and anti-inflammatory treatments for acne. Pulsed dye lasers are used to treat vascular lesions in adults and infants. Further research is necessary to determine the functional significance of visible light on skin health without confounding the influence of ultraviolet and infrared wavelengths.

Visible light. Part II: Photoprotection against visible and ultraviolet light

Cutaneous photobiology studies have focused primarily on the ultraviolet portion of the solar spectrum. Visible light (VL), which comprises 50% of the electromagnetic radiation that reaches the Earth's surface and, as discussed in Part I of this CME, has cutaneous biologic effects, such as pigment darkening and erythema. Photoprotection against VL includes avoiding the sun, seeking shade, and using photoprotective clothing. The organic and inorganic ultraviolet filters used in sunscreens do not protect against VL, only tinted sunscreens do. In the United States, these filters are regulated by the Food and Drug Administration as an over-the-counter drug and are subject to more stringent regulations than in Europe, Asia, and Australia. There are no established guidelines regarding VL photoprotection. Alternative measures to confer VL photoprotection are being explored. These novel methods include topical, oral, and subcutaneous agents. Further development should focus on better protection in the ultraviolet A1 (340-400 nm) and VL ranges while enhancing the cosmesis of the final products.

High-fluence light emitting diode-red light inhibits cell cycle progression in human dermal fibroblasts

Skin fibrosis is a debilitating feature of several systemic and dermatologic diseases. While current treatment options carry significant risk of side effects and recurrence, high-fluence light emitting diode-generated red light (LED-RL) is an alternative therapeutic that is safe, non-invasive, and accessible. We previously demonstrated LED-RL decreases fibroblast proliferation, a key pathogenic component of fibrosis. However, the cellular mechanism by which high fluence LED-RL modulates fibroblast proliferation is unclear. Herein, we explored the effects of high fluence LED-RL on human dermal fibroblast cell cycle progression. We demonstrate that LED-RL at 640 J/cm² induced significant arrest of cells in G₀ /G₁ compared to temperature-matched control. This was accompanied by a corresponding increase in expression of checkpoint regulator p53 in irradiated cells. These data demonstrate high fluence LED-RL may exert its anti-proliferative effect on fibroblasts by inducing G₀ /G₁ arrest. Further, this study provides insight into the molecular mechanism underlying LED-RL as an anti-fibrotic therapeutic.

The IL-4/IL-13 axis in skin fibrosis and scarring: mechanistic concepts and therapeutic targets

Skin fibrosis, characterized by excessive fibroblast proliferation and extracellular matrix deposition in the dermis, is the histopathologic hallmark of dermatologic diseases such as systemic sclerosis, hypertrophic scars, and keloids. Effective anti-scarring therapeutics remain an unmet need, underscoring the complex pathophysiologic mechanisms of skin fibrosis. The Th2 cytokines interleukin (IL)-4 and IL-13 have been implicated as key mediators in the pathogenesis of fibroproliferative disorders. The goal of this article is to summarize the current understanding of the role of the IL-4/IL-13 axis in wound healing and skin fibrosis. We conducted a literature search to identify research studies investigating the roles of IL-4 and IL-13 in fibrotic skin diseases. While transforming growth factor-beta has long been regarded as the main driver of fibrotic processes, research into the cellular and molecular biology of wound healing has revealed other pathways that promote scar tissue formation. IL-4 and IL-13 are important mediators of skin fibrosis, supported by evidence from in vitro data, animal models of fibrosis, and clinical studies. Overactive signaling of the IL-4/IL-13 axis contributes to the initiation and perpetuation of fibrotic skin diseases. Further insights into the IL-4/IL-13 axis may reveal potential targets for the development of novel therapies that prevent or treat fibrotic skin diseases.

Safety of light emitting diode-red light on human skin: Two randomized controlled trials

Therapeutic applications of light emitting diode-red light (LED-RL) are expanding, yet data on its clinical effects are lacking. Our goal was to evaluate the safety of high fluence LED-RL (≥160 J/cm² ). In two phase I, single-blind, dose escalation, randomized controlled trials, healthy subjects received LED-RL or mock irradiation to the forearm thrice weekly for 3 weeks at fluences of 160-640 J/cm² for all skin types (STARS 1, n = 60) and at 480-640 J/cm² for non-Hispanic Caucasians (STARS 2, n = 55). The primary outcome was the incidence of adverse events (AEs). The maximum tolerated dose was the highest fluence that did not elicit predefined AEs. Dose-limiting AEs, including blistering and prolonged erythema, occurred at 480 J/cm² in STARS 1 (n = 1) and 640 J/cm² in STARS 2 (n = 2). AEs of transient erythema and hyperpigmentation were mild. No serious AEs occurred. We determined that LED-RL is safe up to 320 J/cm² for skin of color and 480 J/cm² for non-Hispanic Caucasian individuals. LED-RL may exert differential cutaneous effects depending on race and ethnicity, with darker skin being more photosensitive. These findings may guide future studies to evaluate the efficacy of LED-RL for the treatment of various diseases.

Facial rejuvenation using photodynamic therapy with a novel preparation of ALA and hyaluronic acid in young adults

Photodynamic therapy (PDT) is a well-established, non-invasive treatment modality that has shown desirable effects such as improvement of fine lines, dyspigmentation, and other signs of photodamage. Many patients seek to decrease, or reverse, effects of sun damage on the skin. Hyaluronic acid (HA), a naturally occurring glycosaminoglycan found in the body, has enormous potential to bind water which allows the skin to retain moisture and maintain elasticity. Topical application of HA has been found to produce anti-wrinkle effects. We conducted a pilot case series evaluating the safety and efficacy of a commercially available 2% 5-aminolevulinic acid (ALA) gel with hyaluronic acid (ALA-HA) and light-emitting diode-red light (LED-RL) for facial rejuvenation as determined by clinical assessments and digital skin analysis of rhytides, pore size, and erythema. All patients noted improvement of their skin and experienced minimal pain during PDT. Evaluation by dermatologists demonstrated significant improvement in overall skin appearance. Digital analysis of photographs revealed improvement of skin spots, wrinkles, pores, texture, UV spots, brown spots, red areas, and porphyrins. Our findings demonstrated safety and efficacy of this novel preparation of photodynamic gel with HA and subsequent activation with LED-RL.

Topical Treatments for Melasma: A Systematic Review of Randomized Controlled Trials

Background: Melasma is an acquired skin disease characterized by symmetric hyperpigmentation on sun-exposed areas, particularly on the face. Recently, there has been tremendous scientific interest in novel, safe, and effective topical agents to manage melasma. Objective: To evaluate topical treatments for melasma and provide evidence-based recommendations for clinical use and further research. Methods: We performed a systematic review of randomized controlled trials (RCTs) on topical agents for the treatment of melasma on March 4th, 2019 using PRISMA guidelines. Clinical recommendations were based on the American College of Physicians guidelines. Results: After screening, we identified 35 original RCTs using azelaic acid, cysteamine, epidermal growth factor, hydroquinone (liposomal-delivered), lignin peroxidase, mulberry extract, niacinamide, Rumex occidentalis, triple combination therapy, tranexamic acid, 4-n-butylresorcinol, glycolic acid, kojic acid, aloe vera, ascorbic acid, dioic acid, ellagic acid and arbutin, flutamide, parsley, or zinc sulfate for melasma. Conclusions: Cysteamine, triple combination therapy, and tranexamic acid received strong clinical recommendations for the treatment of melasma. Cysteamine has excellent efficacy and is reported to have anti-cancer properties, but has not been directly compared with hydroquinone. Triple combination agents and tranexamic acid are effective, but carry theoretical risks for ochronosis and thrombosis, respectively. Natural compounds are associated with low risk for adverse events, but more research is needed to determine the efficacy, optimal formulation, and appropriate concentration of novel treatments. J Drugs Dermatol. 2019;18(11):1156-1171.