Iberia Consensus on Strategies to Prevent and Manage Irritation by Topical Retinoids in Facial and Trunk Acne. / Consenso Iberia sobre estrategias de prevención y manejo de la irritación por retinoides tópicos en acné localizado en cara y tronco.

OBJECTIVE: To assess the level of agreement on various prevention and management strategies for irritation caused by topical retinoids in facial and trunk acne in an attempt to alleviate it and minimize treatment discontinuations as much as possible. METHOD: After reviewing the scientific medical literatura currently available, 4 different areas of uncertainty in the management of irritation caused by topical retinoids in acne were identified. A questionnaire with 34 recommendations was created and evaluated by a group of 133 dermatologists (Delphi methodology). RESULTS: In 82.3% of the recommendations (28 out of 34), some level of agreement was reached (≥ 85% agreement in 22 recommendations and ≥ 70% agreement in 6). The results with the highest level of agreement focused on specific patient education strategies (explaining that irritation is an expected reaction at the beginning of treatment and tends to decrease over time), gradual and/or spaced application of topical retinoids (at night time to prevent and/or reduce skin irritation), and the importance of using adjuvant products, specific for acne-prone skin, hydration, photoprotection, and skin cleansing. These recommendations reflect a comprehensive approach to managing irritation associated with topical retinoids and promoting long-term adherence. CONCLUSIONS: Skin irritation caused by topical retinoids in facial and trunk acne is an expected, mild, and controllable reaction if proper prevention and management guidelines are followed, meaning that it should not be a reason for treatment discontinuation.

Isotretinoin as a promising option in the treatment of facial papules of frontal fibrosing alopecia.

Frontal fibrosing alopecia (FFA) is a primary cicatricial alopecia characterized by hairline recession, pruritus, and facial papules (FP). Various therapies are used to stabilize disease activity and induce remission. However, FP of FFA is resistant to treatment in many cases. In this review, we searched the PubMed and Google Scholar databases to screen the published literature on treatment options for FP in the context of FFA. Overall, 12 studies were included in this review. Available literature suggests a noticeable improvement in resistant-to-treatment FP in FFA patients with oral isotretinoin. The available evidence is limited and is derived from retrospective studies and case reports/series. Systemic isotretinoin can be considered a promising therapeutic regimen for treating resistant-to-treatment FP of FFA patients. However, more extensive, well-designed studies are necessary for confirmatory evidence.

Adverse Pregnancy and Child Outcomes in Oral Retinoid-Exposed Pregnancies: A Nationwide Population-Based Study.

BACKGROUND: Oral retinoids are used to treat various dermatological conditions, and their use is increasing in women of childbearing age. However, there is limited knowledge on the incidence of adverse outcomes after retinoid exposure during pregnancy. We aimed to evaluate the risk of adverse outcomes associated with oral retinoid exposure during pregnancy. METHODS: We conducted a retrospective cohort study using the NHIS mother-child linked healthcare database in South Korea. We included all women who gave live birth from April 1, 2009 to December 31, 2020 and their children. The exposure was defined as having ≥ 1 prescription of isotretinoin, alitretinoin, and acitretin from one month before pregnancy to the delivery. The outcomes of interest were adverse child outcomes including major congenital malformations, low birth weight, and neurodevelopmental disorders (autism spectrum disorder and intellectual disorder), and adverse pregnancy outcomes including gestational diabetes mellitus, preeclampsia, and postpartum hemorrhage. Propensity score-based matching weights were used to control for various potential confounders. For congenital malformation, low birth weight, and adverse pregnancy outcomes, we calculated relative risk (RR) with 95% confidence interval (CI) using a generalized linear model and for neurodevelopmental disorders, we estimated hazard ratio (HR) with 95% CI using the Cox proportional hazard model. RESULTS: Of 3,894,184 pregnancies, we identified 720 pregnancies (0.02%) as the oral retinoid-exposed group. The incidence of major congenital malformation was 400.6 per 10,000 births for oral retinoid-exposed group and 357.9 per 10,000 births for unexposed group and the weighted RR was 1.10 (95% CI, 0.65-1.85) in oral retinoid-exposed group compared with unexposed group. The neurodevelopmental disorder showed a potential increased risk, with the weighted HR of 1.63 (95% CI, 0.60-4.41) for autism spectrum disorder and 1.71 (95% CI, 0.60-4.93) for the intellectual disorder, although it did not reach statistical significance. For low birth weight and adverse pregnancy outcomes, no association was observed with oral retinoid exposure during pregnancy. CONCLUSION: This study found no significantly increased risk of congenital malformations, autism spectrum disorders, and intellectual disability associated with oral retinoid exposure during pregnancy; however, given the limitations such as including only the live births and increased point estimate, potential risk cannot be fully excluded.

Topical retinoids: Novel derivatives, nano lipid-based carriers, and combinations to improve chemical instability and skin irritation.

BACKGROUND: Retinoids, defined as synthetic or natural derivatives of vitamin A, have been extensively studied as anti-aging molecules that are widely applied in cosmetics. However, due to their physicochemical property, retinoids are highly unstable and extremely sensitive to light, oxygen, and temperature. Moreover, topical application of retinoids often leads to cutaneous irritation. These instabilities and irritant properties of retinoids limit their application in cosmetic and pharmaceutical products. AIM: Our study aimed to provide a systematic review to summarize the mechanisms underlying the instability and irritant properties of retinoids, as well as recent developments in addressing these challenges. METHODS: A comprehensive PubMed search was conducted using the following keywords: retinoids, chemical instability, skin irritation, retinoid derivatives, nano lipid-based carriers, liposomes, penetration-enhancer vesicles, ethosomes, niosomes, nanoemulsions, solid lipid nanoparticles, vitamins, soothing and hydrating agents, antioxidants and metal chelator and retinol combinations. Relevant researches published between 1968 and 2023 and studies related to these reports were reviewed. RESULTS: The development of new retinoid derivatives, the utilization of new delivery systems like nano lipid-based carriers and the combination with other compounds like vitamins, soothing agents, antioxidants and metal chelator have been explored to improve the stability, bioavailability, and toxicity of the retinoid family. CONCLUSIONS: Through advancements in formulation techniques, structure modification of retinoid derivatives and development of novel nano lipid-based carriers, the chemical instability and skin irritation of retinoids has been mitigated, ensuring their efficacy and potency over extended periods.

Molecular Interactions of Selective Agonists and Antagonists with the Retinoic Acid Receptor γ.

All-trans retinoic acid (ATRA), the major active metabolite of all-trans retinol (vitamin A), is a key hormonal signaling molecule. In the adult organism, ATRA has a widespread influence on processes that are crucial to the growth and differentiation of cells and, in turn, the acquisition of mature cell functions. Therefore, there is considerable potential in the use of retinoids to treat diseases. ATRA binds to the retinoic acid receptors (RAR) which, as activated by ATRA, selectively regulate gene expression. There are three main RAR isoforms, RARα, RARß, and RARγ. They each have a distinct role, for example, RARα and RARγ regulate myeloid progenitor cell differentiation and hematopoietic stem cell maintenance, respectively. Hence, targeting an isoform is crucial to developing retinoid-based therapeutics. In principle, this is exemplified when ATRA is used to treat acute promyelocytic leukemia (PML) and target RARα within PML-RARα oncogenic fusion protein. ATRA with arsenic trioxide has provided a cure for the once highly fatal leukemia. Recent in vitro and in vivo studies of RARγ have revealed the potential use of agonists and antagonists to treat diseases as diverse as cancer, heterotopic ossification, psoriasis, and acne. During the final drug development there may be a need to design newer compounds with added modifications to improve solubility, pharmacokinetics, or potency. At the same time, it is important to retain isotype specificity and activity. Examination of the molecular interactions between RARγ agonists and the ligand binding domain of RARγ has revealed aspects to ligand binding that are crucial to RARγ selectivity and compound activity and key to designing newer compounds.

Identifying Molecular Pathophysiology and Potential Therapeutic Options in Iatrogenic Tracheal Stenosis.

INTRODUCTION: While most patients with iatrogenic tracheal stenosis (ITS) respond to endoscopic ablative procedures, approximately 15% experience a recalcitrant, recurring disease course that is resistant to conventional management. We aimed to explore genetic profiles of patients with recalcitrant ITS to understand underlying pathophysiology and identify novel therapeutic options. METHODS: We collected 11 samples of granulation tissue from patients with ITS and performed RNA sequencing. We identified the top 10 most highly up- and down-regulated genes and cellular processes that these genes corresponded to. For the most highly dysregulated genes, we identified potential therapeutic options that favorably regulate their expression. RESULTS: The dysregulations in gene expression corresponded to hyperkeratinization (upregulation of genes involved in keratin production and keratinocyte differentiation) and cellular proliferation (downregulation of cell cycle regulating and pro-apoptotic genes). Genes involved in retinoic acid (RA) metabolism and signaling were dysregulated in a pattern suggesting local cellular RA deficiency. Consequently, RA also emerged as the most promising potential therapeutic option for ITS, as it favorably regulated seven of the ten most highly dysregulated genes. CONCLUSION: This is the first study to characterize the role of hyperkeratinization and dysregulations in RA metabolism and signaling in the disease pathophysiology. Given the ability of RA to favorably regulate key genes involved in ITS, future studies must explore its efficacy as a potential therapeutic option for patients with recalcitrant ITS.

Teratogenicity is more likely a function of primary and secondary pharmacology than caused by chemically reactive metabolites: a critical evaluation of 40 years of scientific research.

The number of therapeutic drugs known to be human teratogens is actually relatively small. This may reflect the rigorous animal testing and well defined labelling. Some of these drugs were identified to have reactive metabolites and this has been postulated, historically, to be their teratogenic mechanism. These drugs include thalidomide, various anticonvulsants and retinoic acid derivatives.Many of these experiments were conducted in a period where chemically reactive metabolites were being intensely investigated and associated with all forms of toxicity. The legacy of this is that these examples are routinely cited as well established mechanisms.Examination of mechanism leads to the conclusion that the teratogenicity in humans of these compounds is likely due to the primary and secondary pharmacology of the parent drug and stable circulating metabolites and that association of reactive metabolites to this toxicity is unwarranted.

Pharmacological Management and Potentially Inappropriate Prescriptions for Patients with Acne.

Objective: Acne is a chronic inflammatory disease that involves the pilosebaceous follicle. Its pharmacological treatment involves topical and systemic medications, but a heterogeneous group of drugs may exacerbate or induce skin lesions. The aim of this study was to identify the pharmacological management and medications related to the exacerbation of skin lesions in patients diagnosed with acne. Methods: This was a cross-sectional study that identified the outpatient medication prescription patterns of patients with acne from a dispensing database of 8.5 million members of the Colombian Health System. Sociodemographic and pharmacological variables and the identification of prescriptions that were potentially inappropriate due to the risk of worsening acne were considered. Results: A total of 21,604 patients with acne were identified. Median age was 20.8 years (interquartile range: 17.3-27.3 years), and 60.7 percent were female. Treatment mainly involved antibiotics (79.9% of patients), especially doxycycline (66.0%), and retinoids (55.7%). A total of 17.2 percent of patients had potentially inappropriate prescriptions, predominantly progestogens with androgenic properties (8.9%). Female patients (odds ratio [OR]: 3.55; 95% confidence interval [CI]:3.24-3.90) and patients with pathologies such as systemic lupus erythematosus (OR: 18.61; 95% CI: 7.23-47.93) and rheumatoid arthritis (OR: 10.80; 95% CI: 5.02-23.23) were more likely to receive inappropriate prescriptions, and the risk increased with each year of life (OR: 1.02; 95% CI: 1.02-1.03). Limitations: Access to medical records was not obtained to verify clinical characteristics of acne. Conclusion: Patients with acne are excessively treated with systemic antibiotics, counter to clinical practice guidelines. Approximately one-fifth of these patients received some potentially inappropriate medication that could exacerbate their skin lesions.

Prescription retinoid and contraception use in women in Australia: A population-based study.

BACKGROUND/OBECTIVES: Oral retinoids are teratogenic, and pregnancy avoidance is an important part of retinoid prescribing. Australia does not have a standardised pregnancy prevention programme for women using oral retinoids, and the contraception strategies for women who use oral retinoids are not well understood. The objectives were to determine trends in the use of prescription retinoids among Australian reproductive-aged women and whether women dispensed oral retinoids used contraception concomitantly. METHODS: This was a population-based study using Australian Pharmaceutical Benefits (PBS) dispensing claims for a random 10% sample of 15-44-year-old Australian women, 2013 - 2021. We described rates and annual trends in dispensing claims for PBS-listed retinoids and contraceptives. We also estimated concomitant oral retinoid and contraceptive use on the day of each retinoid dispensing and determined if there was a period of contraceptive treatment that overlapped. Estimates were then extrapolated to the national level. RESULTS: There were 1,545,800 retinoid dispensings to reproductive-aged women; 57.1% were oral retinoids. The rate of retinoid dispensing to reproductive-aged women increased annually, from 28 dispensings per 1000 population in 2013 to 41 per 1000 in 2021. The rate of oral retinoid dispensing doubled over the study period, from 14 dispensings per 1000 population in 2013 to 28 per 1000 in 2021, while topical retinoid dispensing did not change. Only 25% of oral retinoid dispensings had evidence of concomitant contraceptive use in 2021. CONCLUSIONS: Rates of oral retinoid dispensing have doubled among reproductive-aged women over the past decade. A large percentage of oral retinoid use does not appear to have concomitant contraception use, posing a risk of teratogenic effects in pregnancies.

Therapeutic dosage of isotretinoin in rats may influence orthodontic tooth movement.

Objective Isotretinoin, also known as 13-cis-retinoic acid, is an isomer of tretinoin, the oxidized form of Vitamin A. Orthodontic tooth movement (OTM) is the result of a cascade of inflammatory responses stimulated by a physical element that is the force generated by orthodontic appliances. Isotretinoin is mainly used among adolescents and young adults, and coincidentally it is this age group that also undergoes orthodontic treatment. Materials and Methods Fifty-five animals were used, and they were randomly divided into 11 groups, containing 5 animals in each group. Group 1: Control; Group 2: OTM for 7 days; Group 3: OTM for 14 days; Group 4: Treated with isotretinoin for 14 days with a dosage of 7.5 mg/kg/day; Group 5: Treated with isotretinoin for 14 days with a dosage of 1.0 mg/kg/day; Group 6: Treated with isotretinoin for 21 days with a dosage of 7.5 mg/kg/day; Group 7: Treated with isotretinoin for 21 days with a dosage of 1.0 mg/kg/day; Group 8: Treated with isotretinoin for 14 days with a dosage of 7.5 mg/kg/day and undergoing OTM for 7 days; Group 9: Treated with isotretinoin for 14 days with a dosage of 1.0 mg/kg/day and undergoing OTM for 7 days; Group 10: Treated with isotretinoin for 21 days with a dosage of 7.5 mg/kg/day and undergoing OTM for 14 days; Group 11: Treated with isotretinoin for 21 days with a dosage of 1.0 mg/kg/day and undergoing OTM for 14 days. In Groups 8, 9, 10 and 11, the animals were treated with isotretinoin for 7 days before OTM and maintained during the movement period in the respective groups. Results There was a significant difference in microtomographic parameters, including Trabecular Volume (BV/TV), Trabecular Thickness (Tb.Th), Number of Trabeculae (Tb.N), and Trabecular Separation (Tb.Sp), between the groups. The group that received orthodontic force in conjunction with isotretinoin treatment at a dosage of 7.5 mg/kg/day exhibited lower tooth displacement over a period of 21 days and 14 days. Conclusion Isotretinoin caused a reduction in tooth displacement during OTM when administered at a dose of 7.5 mg/kg/day and isotretinoin did change the microtomographic parameters of treated animals.

Attempts to Improve Lipophilic Drugs' Solubility and Bioavailability: A Focus on Fenretinide.

The development of numerous drugs is often arrested at clinical testing stages, due to their unfavorable biopharmaceutical characteristics. It is the case of fenretinide (4-HPR), a second-generation retinoid, that demonstrated promising in vitro cytotoxic activity against several cancer cell lines. Unfortunately, response rates in early clinical trials with 4-HPR did not confirm the in vitro findings, mainly due to the low bioavailability of the oral capsular formulation that was initially developed. Capsular 4-HPR provided variable and insufficient drug plasma levels attributable to the high hepatic first-pass effect and poor drug water solubility. To improve 4-HPR bioavailability, several approaches have been put forward and tested in preclinical and early-phase clinical trials, demonstrating generally improved plasma levels and minimal systemic toxicities, but also modest antitumor efficacy. The challenge is thus currently still far from being met. To redirect the diminished interest of pharmaceutical companies toward 4-HPR and promote its further clinical development, this manuscript reviewed the attempts made so far by researchers to enhance 4-HPR bioavailability. A comparison of the available data was performed, and future directions were proposed.

Structure-Activity Relationships and Therapeutic Applications of Retinoids in View of Potential Benefits from Drug Repurposing Process.

Vitamin A, an essential micronutrient, is integral to various biological processes crucial for organismal development and maintenance. Dietary sources of vitamin A encompass preformed retinol, retinyl esters, and provitamin A carotenoids. Retinoic acid (RA), a key component, plays pivotal roles in vision, cell proliferation, apoptosis, immune function, and gene regulation. Drug repurposing, an effective strategy for identifying new therapeutic applications for existing drugs, has gained prominence in recent years. This review seeks to provide a comprehensive overview of the current research landscape surrounding retinoids and drug repurposing. The scope of this review encompasses a comprehensive examination of retinoids and their potential for repurposing in various therapeutic contexts. Despite their efficacy in treating dermatological conditions, concerns about toxicity persist, driving the search for safer and more potent retinoids. The molecular mechanisms underlying retinoid activity involve binding to retinoic acid receptors (RARs) and retinoid X receptors (RXRs), leading to transcriptional regulation of target genes. This review seeks to shed light on the possibilities for repurposing retinoids to cover a wider spectrum of therapeutic uses by exploring recent scientific progress. It also aims to offer a more comprehensive understanding of the therapeutic prospects of retinoids and the broader impact of drug repositioning in contemporary medicine.

Topical and Systemic Retinoids in the Management of Hidradenitis Suppurativa: A Comprehensive Literature Review.

Hidradenitis suppurativa (HS) is a debilitating chronic skin disorder characterized by painful inflammatory nodules, abscesses and sinus tracts involving intertriginous areas and has an adverse impact on patient quality of life. Over the past decade, the therapeutic options of HS have increased significantly to comprise multiple modalities, including topical medication, systemic therapies (mainly antibiotics, retinoids, and biologics), surgical approaches, and lifestyle modifications. Biologics alone or in combination with surgery remain the treatment of choice for moderate to severe disease. However, non-biologic therapies (including retinoids) may be used as monotherapy for mild disease and in combination with biologics and surgical treatment in moderate to severe disease. Retinoids, specifically isotretinoin, acitretin, and alitretinoin, are historically used in the management of HS, supported by anecdotal evidence and with variable treatment response. Although the current American and European guidelines offer different recommendations on the use of retinoids in HS, retinoids remain a valuable ally in HS management. This review provides a comprehensive analysis of the current scientific literature on retinoid therapy (topical and systemic) in HS, highlighting disparities in mechanisms of action, efficacy, and safety to clarify their role in HS treatment.

Comparison of the Efficacy of Clascoterone, Trifarotene, and Tazarotene for the Treatment of Acne: A Systematic Literature Review and Meta-Analysis.

INTRODUCTION: Acne vulgaris, a chronic inflammatory condition, is associated with significant physical and psychosocial burden. Since 2019, three new topical agents for acne vulgaris have been approved in the USA and Canada. We performed a systematic review and meta-analysis to compare the efficacy between twice-daily clascoterone cream 1%, once-daily trifarotene 0.005% cream, and once-daily tazarotene 0.045% lotion for acne treatment. METHODS: Randomized controlled trials (RCTs) comparing clascoterone, trifarotene, or tazarotene with vehicle in patients with moderate-to-severe acne were identified from a systematic literature review and included in a meta-analysis. Primary outcomes were percentage reduction in inflammatory and noninflammatory lesion count (ILC and NILC, respectively) and treatment success rate (≥ 2-grade improvement in Investigator's Global Assessment or Evaluator's Global Severity Score and a rating of clear or almost clear) at week 12. DerSimonian and Laird random-effects models with the inverse variance method were used to calculate the mean difference (MD) for percentage reduction in ILC and NILC, and odds ratios (ORs) for the rate of treatment success. RESULTS: Six Phase 3 RCTs were included in the meta-analysis. The analyses showed robust differences favoring the interventions for ILC (MD: - 11.5; 95% confidence interval [CI]: - 14.39, - 8.62), NILC (MD: - 12.25; 95% CI: - 15.21, - 9.29), and treatment success rate (OR: 2.14; 95% CI: 1.81, 2.53). No differences were observed between clascoterone, trifarotene, and tazarotene for ILC (MD: - 12.8, - 11.2, and - 10.1, respectively), NILC (MD: - 11.6, - 13.9, and - 12.8, respectively), or treatment success rate (OR: 2.9, 1.9, and 2.1, respectively (all P > 0.05). CONCLUSION: No significant differences in efficacy were observed between clascoterone, trifarotene, and tazarotene after 12 weeks of treatment in patients with moderate-to-severe acne. Differences in application frequency and safety profile should also be taken into consideration when making treatment decisions.

Double-duty isomerases: a case study of isomerization-coupled enzymatic catalysis.

Enzymes can usually be unambiguously assigned to one of seven classes specifying the basic chemistry of their catalyzed reactions. Less frequently, two or more reaction classes are catalyzed by a single enzyme within one active site. Two examples are an isomerohydrolase and an isomero-oxygenase that catalyze isomerization-coupled reactions crucial for production of vision-supporting 11-cis-retinoids. In these enzymes, isomerization is obligately paired and mechanistically intertwined with a second reaction class. A handful of other enzymes carrying out similarly coupled isomerization reactions have been described, some of which have been subjected to detailed structure-function analyses. Herein we review these rarefied enzymes, focusing on the mechanistic and structural basis of their reaction coupling with the goal of revealing catalytic commonalities.

Acitretin-Induced Repigmentation of Gray Hair: A Case Report.

Acitretin is an oral retinoid with alopecia as a possible adverse effect. However, repigmentation of the hair color after acitretin is not a well-documented phenomenon. Herein, we introduce a case where a patient's hair color darkened after a course of acitretin.

Case report: Hypertrophic lichen planus initially misdiagnosed as squamous cell carcinoma.

Fewer than 26 case reports describe hypertrophic lichen planus (HLP) misdiagnosed as cutaneous squamous cell carcinoma (cSCC). It can be difficult to distinguish between HLP and cSCC, as these two conditions share many clinical and histopathological characteristics. Patients who are misdiagnosed with cSCC often undergo unnecessary medical and/or surgical interventions before receiving a diagnosis of HLP and improving on HLP-directed therapy. This case series highlights the course of three female patients, referred to a single tertiary institution between 2018 and 2022, who were initially misdiagnosed with cSCC before receiving a diagnosis of HLP. We have emphasized the clinical and histopathological distinguishing features between HLP and cSCC, the pathogenesis of HLP, and current and new HLP-directed therapy. We hope that this case series serves as a reminder to dermatologists, dermatologic surgeons, and dermatopathologists to be aware of this diagnostic challenge.