A preliminary study on topical cetirizine in the therapeutic management of androgenetic alopecia

Topical dutasteride for androgenic alopecia: current state and prospects

Androgenic alopecia has a high incidence, affecting 80% of men and 50% of women in their lifetimes. Although not a life-threatening disease, it can be a deep psychological burden to patients and still lacks an effective and safe treatment. Dutasteride is a5-alpha-reductase inhibitor approved to treat benign prostatic hyperplasia that is also commonly prescribed off-label to treat androgenic alopecia. However, oral dutasteride may cause several severe sexual and neurological sideeffects. Therefore, an effective, localized dutasteride treatment that can reduce the effects of systemic uptake is of great interest. Here, we review available therapies to treat androgenic alopecia focusing on topicalformulations developed thus far-including minoxidil, finasteride, and cosmetics-and on dutasteride-loaded nanocarriers targeting hair follicles.

Androgenetic Alopecia: A Review

This study reviewed the current knowledge on the epidemiology, pathophysiology, clinical presentations, diagnosis, treatment, quality-of-life assessment and recent trends in androgenetic alopecia (AGA). Relevant articles on AGA from PubMed, Google Scholar, Medline and Scopus from 1950 to 2024 were obtained and scrutinized.. Key search words included each term like 'androgenetic alopecia', 'androgenic alopecia', 'pattern baldness' and 'pattern hair loss' AND each term like 'epidemiology', 'pathophysiology', 'genetics', 'hormones', 'micronutrient', 'stress and inflammation', 'growth factors', 'clinical features', 'staging', 'cardiovascular associations', 'diagnosis' and 'management' were used in the search. AGA is a non-scarring hair loss that is exemplified by a progressive decline of hair follicles, or non-functional or dead hair follicles in the scalp in a defined pattern. It is the most common hair loss, more common in men but can also present in younger age as premature AGA. Hormones, genetics, micronutrient deficiency, microinflammation and stress have been implicated, while psychosocial distress and cutaneous correlate of cardiovascular diseases have become sources of relentless research. AGA is a patterned hair loss that is more prevalent in Men. It results from the interactions between hormonal, genetic and other factors which determine the extent of hair loss and associated disorders (psychosocial and cardiovascular). As results of more research become available, the extent of AGA, its comorbidities as well as the full spectrum of their manifestations will continue to be sources of health education and more holistic examination by dermatologists and patients.

Management of androgenic alopecia: a systematic review of the literature

We aimed to determine the efficacy of the various available oral, topical, and procedural treatment options for hair loss in individuals with androgenic alopecia. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review of the National Library of Medicine was performed. Overall, 141 unique studies met our inclusion criteria. We demonstrate that many over the counter (e.g. topical minoxidil, supplements, low-level light treatment), prescription (e.g. oral minoxidil, finasteride, dutasteride), and procedural (e.g. platelet-rich plasma, fractionated lasers, hair transplantation) treatments successfully promote hair growth, highlighting the superiority of a multifaceted and individualized approach to management.

A Cross-sectional Observational Study to Correlate the Trichoscopic Findings of Female Pattern Hair Loss with the Disease Severity and Underlying Histopathological Changes

Background

The increasing prevalence of female pattern hair loss (FPHL) is an alarming concern. Trichoscopy is an important bedside diagnostic tool for the diagnosis of FPHL, but there are very few studies correlating it with disease severity or histopathological findings which would provide a better insight to the treating clinician. Hence, we decided to take up this study.

Aim

This study aimed to study the trichoscopic findings of FPHL and correlate their relationship with disease severity and histopathological finding in our tertiary care hospital.

Materials and Methods

Ninety females attending the dermatology outpatient department who were clinically diagnosed with FPHL were included in the study after informed consent and clearance from the institutional ethics committee. This was followed by a detailed history, clinical examination, and trichoscopic assessment. A trichoscopy-guided biopsy was performed from two sites. After the data collection, the statistical software used was IBM SPSS version 21.0 and Microsoft Office Excel 2007. P < 0.05 was accepted as indicative of statistical significance.

Results

Anisotrichosis, increased interfollicular distance, and decreased hairs per follicular unit were universal. Brown peripilar sign had a positive association with inflammation (P < 0.0005) and white peripilar sign with duration of disease and fibrosis whereas dartboard sign had a significant association with inflammation as well as fibrosis.

Conclusion

Trichoscopy helps in diagnosing the condition, assessing the severity, and monitoring the response to treatment. A knowledge about the features underlying specific trichoscopic signs such as inflammation and fibrosis would help the clinician decide the line of management.

Suspected adverse reactions to medications and food supplements containing Serenoa repens: A worldwide analysis of pharmacovigilance and phytovigilance spontaneous reports

The safety of Serenoa repens (SR)-containing products was evaluated conducting a retrospective worldwide analysis of pharmaco- and phytovigilance report forms of suspected adverse reactions (SARs) collected up to 31 January 2022. Multivariate logistic regression was performed to estimate the odds ratios (ORs) of serious SAR. A total of 1810 report forms were analysed; 92% of subjects were males, with a median age of 69 years; 44% of cases were defined as serious. Subjects exposed to dietary supplements had a higher risk of developing serious SARs (OR: 1.60 [95% CI: 1.20-2.15]), as subjects exposed to 2-5 (OR: 1. 83 [95% CI: 1.30-2.58]) or more than 5 (OR: 3.45 [95% CI: 2.36-5.06]) suspect/interacting products. The probability of experiencing serious SAR was higher for subjects exposed to concomitant products (OR: 1.55 [95% CI: 1.15-2.08]), to more than four active compounds (OR: 4.38 [95% CI: 3.21-5.99]) and to SR for more than 14 days (OR: 1.89 [95% CI: 1.10-3, 22]), and lower for subjects exposed to higher doses of SR (OR: of 0.34 [95% CI: 0.20-0.58]). This evidence improves awareness on safety of SR containing products, suggesting the need of a further update of periodic reviews by national and international regulatory agencies.

Formulation optimization, in vitro and in vivo evaluation of niosomal nanocarriers for enhanced topical delivery of cetirizine

Cetirizine hydrochloride (CTZ), a second-generation anti-histaminic drug, has been recently explored for its effectiveness in the treatment of alopecia. Niosomes are surfactant-based nanovesicular systems that have promising applications in both topical and transdermal drug delivery. The aim of this study was to design topical CTZ niosomes for management of alopecia. Thin film hydration technique was implemented for the fabrication of CTZ niosomes. The niosomes were examined for vesicle size, surface charge, and entrapment efficiency. The optimized niosomal formulation was incorporated into a hydrogel base (HPMC) and explored for physical characteristics, ex vivo permeation, and in vivo dermato-kinetic study. The optimized CTZ-loaded niosomal formulation showed an average size of 403.4 ± 15.6 nm, zeta potential of - 12.9 ± 1.7 mV, and entrapment efficiency percentage of 52.8 ± 1.9%. Compared to plain drug solution, entrapment of CTZ within niosomes significantly prolonged in vitro drug release up to 12 h. Most importantly, ex-vivo skin deposition studies and in vivo dermato-kinetic studies verified superior skin deposition/retention of CTZ from CTZ-loaded niosomal gels, compared to plain CTZ gel. CTZ-loaded niosomal gel permitted higher drug deposition percentage (19.2 ± 1.9%) and skin retention (AUC0-10h 1124.5 ± 87.9 μg/mL.h) of CTZ, compared to 7.52 ± 0.7% and 646.2 ± 44.6 μg/mL.h for plain CTZ gel, respectively. Collectively, niosomes might represent a promising carrier for the cutaneous delivery of cetirizine for the topical management of alopecia.

Therapeutic effects of topical cetirizine in the treatment of female pattern hair loss: a randomized controlled noninferiority trial

BACKGROUND

Female pattern hair loss (FPHL) is the most prevalent form of hair loss in women. It was aimed to evaluate the therapeutic effects of topical cetirizine 1%, versus topical minoxidil 2% in patients with FPHL.

RESEARCH DESIGN AND METHODS

Through a triple-blind randomized clinical trial, 60 women with FPHL were randomly divided into two groups of treatment with topical cetirizine 1% or topical minoxidil 2%. The endpoint was changing in hair loss severity as well as terminal hair density and diameter, according to trichoscopic evaluation. Intention-to-treat analysis was also performed for those who accomplished 3 months of treatment.

RESULTS

Both groups showed improvement in hair diameter and density after 6 months; however, the outcome was significant only in the minoxidil group. According to per-protocol analysis, minoxidil was significantly superior to cetirizine in hair density, but not in hair diameter. According to the hair loss severity scales, FPHL was significantly improved in both the cetirizine and minoxidil groups after 6 months of therapy. The dropout rate due to adverse effects was 10.0% and 6.6% in the cetirizine and minoxidil groups, respectively.

CONCLUSION

Although inferior to topical minoxidil, topical cetirizine can provide favorable therapeutic effects for FPHL, specifically when patient incompatibility with Minoxidil is observed.

TRIAL REGISTRATION

The study is registered in the Iranian Registry of Clinical Trials (IRCT) with the registration code IRCT20200521047536N1.

Comparison between topical cetirizine with minoxidil versus topical placebo with minoxidil in female androgenetic alopecia: a randomized, double-blind, placebo-controlled study

Androgenetic alopecia (AGA) is the most common cause of hair loss in both genders with a higher psychological impact on females. Currently, topical minoxidil is the only FDA-approved treatment for female AGA and it needs life-long application and causes side effects. Cetirizine is an antihistamine that may be effective in hair loss treatment. This study aimed to compare the efficacy and safety of topical cetirizine with minoxidil (group 1) versus topical minoxidil with placebo (group 2) in female patients with AGA. This was a double-blind, randomized, controlled, parallel study conducted at Dermatology Clinic, Cairo University Teaching Hospital (Kasr- Al- Ainy), Egypt. Sixty-six patients with female AGA, aged 20-50 years, Sinclair (II-IV), were randomly assigned to one of the 2 groups for 24 weeks. The trichoscopic parameters, patients' self-assessment, side effects and global photographic assessment were evaluated. There was a statistically significant change from baseline in frontal and vertex terminal and vellus hair density (P < 0.0005) with a significant increase in vertex hair shaft thickness and average number of hairs per follicular unit in group 1 (P < 0.05). Patients reported significantly better scores in patient self-assessment in group 1 (P < 0.05). Side effects were not significantly different between groups (P > 0.05). Topical cetirizine increases hair shaft thickness and results in a higher clinical improvement from patients' perspective with a good safety profile (NCT04481412, study start date: July 2020).

Recent Advances in Understanding of the Etiopathogenesis, Diagnosis, and Management of Hair Loss Diseases

Hair-loss diseases comprise heterogenous conditions with respective pathophysiology and clinicopathological characteristics. Major breakthroughs in hair follicle biology and immunology have led to the elucidation of etiopathogenesis of non-scarring alopecia (e.g., alopecia areata, AA) and cicatricial alopecia (e.g., lichen planopilaris, LPP). High-throughput genetic analyses revealed molecular mechanism underlying the disease susceptibility of hair loss conditions, such as androgenetic alopecia (AGA) and female pattern hair loss (FPHL). Hair loss attracted public interest during the COVID-19 pandemic. The knowledge of hair loss diseases is robustly expanding and thus requires timely updates. In this review, the diagnostic and measurement methodologies applied to hair loss diseases are updated. Of note, novel criteria and classification/scoring systems published in the last decade are reviewed, highlighting their advantages over conventional ones. Emerging diagnostic techniques are itemized with clinical pearls enabling efficient utilization. Recent advances in understanding the etiopathogenesis and management for representative hair diseases, namely AGA, FPHL, AA, and major primary cicatricial alopecia, including LPP, are comprehensively summarized, focusing on causative factors, genetic predisposition, new disease entity, and novel therapeutic options. Lastly, the association between COVID-19 and hair loss is discussed to delineate telogen effluvium as the predominating pathomechanism accounting for this sequela.

The efficacy of topical prostaglandin analogs for hair loss: A systematic review and meta-analysis

Background

Prostaglandin analogs have been found to have more versatile uses: treatment of open-angle glaucoma, high intraocular pressure, vitiligo, and other treatments. And prostaglandin analogs have been found to have an important role in the hair growth cycle. However, prostaglandin analogs have not been sufficiently studied for hair (including hair, eyelashes, and eyebrows) regeneration. In this study, a systematic review and meta-analysis of topical prostaglandin analogs on hair loss was performed.

Objective

The purpose of this meta-analysis is to determine the efficacy and safety of topical prostaglandin analogs for treating hair loss.

Methods

We searched PubMed, Embase, and Cochrane Library databases comprehensively. Data were pooled using Review Manager 5.4.1, and subgroup analyses were performed if necessary.

Results

There were six randomized controlled trials included in this meta-analysis. All studies compared prostaglandin analogs with placebo, and one trial consisted of two sets of data. The results showed that prostaglandin analogs could significantly improve the hair length and density (p &lt; 0.001). As far as adverse events are concerned, there was no significant difference between the experimental group and the control group.

Conclusion

In patients with hair loss, the topical prostaglandin analogs have better therapeutic efficacy and safety than placebo. However, the best dose and frequency of experimental treatment require further studies.

Hair loss during and after breast cancer therapy

For patients diagnosed with breast cancer, alopecia can be a distressing side effect of treatment. Major surgeries, cytotoxic chemotherapy, and endocrine therapy may result in several different types of alopecia. This article reviews the underlying mechanisms, etiology, prevention strategies, and treatment options for chemotherapy-induced alopecia, telogen effluvium, and endocrine-induced alopecia. Here, we aim to provide breast oncologists with a review of the types of hair loss related to cancer therapy and current preventative and treatment options to facilitate informative patient counseling.

What's New in Therapy for Male Androgenetic Alopecia?

Male androgenetic alopecia is a common condition and represents a major concern for patients who experience this condition. While there are different treatments to stop hair loss and improve hair density, the 5-alpha reductase inhibitors have demonstrated to be effective in improving androgenetic alopecia in men and can maintain a positive response for many years. Oral finasteride 1 mg is a US FDA-approved option, but dutasteride 0.5 mg has been proven to induce better responses, especially in the frontal area. Both have been shown to be safe in clinical trials but there is widespread concern about sexual adverse effects among patients. The use of topical finasteride has increased during the last few years as a useful option to avoid systemic therapy. The efficacy of topical finasteride 0.25% daily has been demonstrated in clinical trials, with a less marked decrease in serum dihydrotestosterone levels than with oral intake. Mesotherapy with dutasteride has also become more widespread recently, although evidence of its effectiveness is limited to retrospective studies in real clinical practice. The use of oral minoxidil in androgenetic alopecia has not been approved by the FDA, however several clinical studies have shown that it is an effective treatment option. The initial dose recommended to treat male hair loss is 2.5 mg daily, although the dose is frequently increased to 5 mg daily. The main adverse effect of oral minoxidil is hypertrichosis, followed by dizziness or lower limb edema, which are much less common. Platelet-rich plasma is a non-pharmacological option to treat male androgenetic alopecia, with some clinical trials demonstrating an improvement in hair count after several months. Among the published studies, the main limitation to compare its efficacy is the heterogeneity of the procedure. The most frequent regimens propose treatment every 4 weeks for 3 months initially to assess the individual response. Another treatment alternative is the use of light devices with wavelengths of between 630 and 660 nm, known as low-level laser therapy. These devices can be used at home every day for 15-30 min. Their efficacy has been shown in a limited number of clinical trials; however, there is a lack of evidence about the efficacy of these devices compared with other medical options or as a complementary therapy in hair loss. The pipeline of potential new treatments for male androgenetic alopecia is strong. Pyrilutamide and GT20029 are being studied as topical antagonists of the androgen receptor, while cetirizine is another topical option with some initial promising results. Furthermore, according to isolated studies with heterogeneous treatment schemes, the use of botulinum toxin in the scalp might improve androgenetic alopecia, and lastly, scalp threading might increase the total hair count as growth factors are released during implantation.

Repurposing levocetirizine hydrochloride loaded into cationic ceramide/phospholipid composite (CCPCs) for management of alopecia: central composite design optimization, in- silico and in-vivo studies

Levocetirizine hydrochloride (LVC) is an antihistaminic drug that is repurposed for the treatment of alopecia. This investigation is targeted for formulating LVC into cationic ceramide/phospholipid composite (CCPCs) for the management of alopecia. CCPCs were fabricated by ethanol-injection approach, through a central composite experiment. CCPCs were evaluated by inspecting their entrapment efficiency (EE%), polydispersity index (PDI), particle size (PS), and zeta potential (ZP). The optimum CCPCs were additionally studied by in-vitro, ex-vivo, in-silico, and in-vivo studies. The fabricated CCPCs had acceptable EE%, PS, PDI, and ZP values. The statistical optimization elected optimum CCPCs composed of 5 mg hyaluronic acid, 10 mg ceramide III, and 5 mg dimethyldidodecylammonium bromide employing phytantriol as a permeation enhancer. The optimum CCPCs had EE%, PS, PDI, and ZP of 88.36 ± 0.34%, 479.00 ± 50.34 nm, 0.377 ± 0.0035, and 20.20 ± 1.13 mV, respectively. The optimum CCPC maintained its stability for up to 90 days. It also viewed vesicles of tube shape via transmission electron microscope. The in-silico assessment resulted in better interaction and stability between LVC and vesicle components in water. The ex-vivo and in-vivo assessments showed satisfactory skin retention of LVC from optimum CCPCs. The histopathological assessment verified the safety of optimum CCPCs to be topically applied. Overall, the optimum CCPCs could be utilized as a potential system for the topical management of alopecia, with a prolonged period of activity, coupled with reduced LVC shortcomings.

The physiological and pharmacological roles of prostaglandins in hair growth

Hair loss is a common status found among people of all ages. Since the role of hair is much more related to culture and individual identity, hair loss can have a great influence on well-being and quality of life. It is a disorder that is observed in only scalp patients with androgenetic alopecia (AGA) or alopecia areata caused by stress or immune response abnormalities. Food and Drug Administration (FDA)-approved therapeutic medicines such as finasteride, and minoxidil improve hair loss temporarily, but when they stop, they have a limitation in that hair loss occurs again. As an alternative strategy for improving hair growth, many studies reported that there is a relationship between the expression levels of prostaglandins (PGs) and hair growth. Four major PGs such as prostaglandin D2 (PGD₂), prostaglandin I2 (PGI₂), prostaglandin E2 (PGE₂), and prostaglandin F2 alpha (PGF₂α) are spatiotemporally expressed in hair follicles and are implicated in hair loss. This review investigated the physiological roles and pharmacological interventions of the PGs in the pathogenesis of hair loss and provided these novel insights for clinical therapeutics for patients suffering from alopecia.

Topical cetirizine for treating androgenetic alopecia: A systematic review

BACKGROUND

Cetirizine, a widely used agent for allergic disorders, has recently been topically used for treating androgenetic alopecia (AGA). We aimed to summarize the current evidence regarding the effectiveness and safety of topical cetirizine for treating AGA.

METHODS

We searched Ovid MEDLINE, Embase, and Cochrane Central Register of Controlled Trials. We included both randomized controlled trials (RCTs) and non-randomized clinical trials.

FINDINGS

We initially identified 102 records, of which, we included two RCTs and one non-randomized clinical trial, which were of moderate-to-high risk of bias. All included trials used 1% topical cetirizine as the intervention with various regimens. Topical cetirizine was likely to be more effective than a placebo for treating AGA. In comparison with topical minoxidil, topical cetirizine appears to be less effective for improving total and vellus hair density, but it might have a longer-lasting effect. Further, cetirizine might be as effective as minoxidil in improving hair diameter.

CONCLUSION

One percent topical cetirizine may serve as a choice for treating AGA, especially for patients with a negative response to topical minoxidil. In order to fully understand the role of topical cetirizine for AGA, additional well-designed RCTs are needed.

Clinical aspect, pathogenesis and therapy options of alopecia induced by hormonal therapy for breast cancer

Adjuvant hormonal therapy is one of the most important treatments of hormone-receptor-positive breast cancer and includes selective estrogen receptor modulators, aromatase inhibitors, and luteinizing hormone-releasing hormone analogs. In patients receiving these drugs, a progressive recession of frontal-temporal hairlines is often observed, such as a certain grade of hair miniaturization in the same areas and the central scalp area, producing a pseudo-female androgenic alopecia, which has to be considered oncotherapy-induced alopecia. The aim of this work, is to describe the clinical aspects and pathogenesis of this type of alopecia and to analyze the different drugs which have been proposed until now. The authors concude that topical hormones should not be considered as a therapeutic approach because of their direct or indirect oncogenic potential. A therapeutic approach that could be both safe and effective is proposed.

Lipid Cubic Systems for Sustained and Controlled Delivery of Antihistamine Drugs

Antihistamines are capable of blocking mediator responses in allergic reactions including allergic rhinitis and dermatological reactions. By incorporating various H1 receptor antagonists into a lipid cubic phase network, these active ingredients can be delivered locally over an extended period of time owing to the mucoadhesive nature of the system. Local delivery can avoid inducing unwanted side effects, often observed after systematic delivery. Lipid-based antihistamine delivery systems are shown here to exhibit prolonged release capabilities. In vitro drug dissolution studies investigated the extent and release rate of two model first-generation and two model second-generation H1 antagonist antihistamine drugs from two monoacyglycerol-derived lipid models. To optimize the formulation approach, the systems were characterized macroscopically and microscopically by small-angle X-ray scattering and polarized light to ascertain the mesophase accessed upon an incorporation of antihistamines of varying solubilities and size. The impact of encapsulating the antihistamine molecules on the degree of mucoadhesivity of the lipid cubic systems was investigated using multiparametric surface plasmon resonance. With the ultimate goal of developing therapies for the treatment of allergic reactions, the ability of the formulations to inhibit mediator release utilizing RBL-2H3 mast cells with the propensity to release histamine upon induction was explored, demonstrating no interference from the lipid excipient on the effectiveness of the antihistamine molecules.

Use of H-1 Antihistamine in Dermatology: More than Itch and Urticaria Control: A Systematic Review

H-1 antihistamines are commonly used in dermatological practice for itch and urticaria control. The widespread expression of H-1 receptor on different cells in the skin and various biologic functions of H-1 antihistamines indicate the possible treatment potentials of H-1 antihistamines in dermatology. A literature search was performed on PubMed and Embase, targeting articles reporting use of antihistamine for purposes other than itch and urticaria control in dermatological practice. Several off-label usages of antihistamines were identified, including alopecia, acne, Darier disease, eosinophilic dermatoses, paraneoplastic dermatoses, psoriasis, lichen nitidus, radiation dermatitis, skin dysesthesia, and cutaneous malignancies. Additional benefits were observed when H-1 antihistamines were used either alone or in combination with other therapeutic modalities. Although various novel uses of H-1 antihistamines have been uncovered, the evidence level of most included studies is weak. Further randomized control trials are warranted to better evaluate the efficacy and dosage of H-1 antihistamine for dermatological disorders.

Therapeutic implications of topical cetirizine 1% in treatment of male androgenetic alopecia: A case-controlled study

BACKGROUND

Androgenetic alopecia (AGA) is the most common form of alopecia in men. Cetirizine, a second-generation H1 blocker, is known for its anti-inflammatory properties and its ability to decrease prostaglandin D2 (PGD2) production.

AIM

To evaluate the efficacy and tolerability of topical cetirizine in male patients with AGA.

METHODS

Two groups of 30 patients each (healthy males aged between 22 and 55 years) with different grades of AGA classified according to the Hamilton-Norwood classification were recruited for this study. Group A subjects applied 1 mL of 1% topical cetirizine daily, while group B subjects served as controls and were instructed to apply 1 mL of a placebo solution for 6 months.

RESULTS

Dermoscopic assessment revealed significantly higher hair regrowth among the cetirizine-treated group (P < .001). The patients' satisfaction was significantly higher among the cetirizine-treated group (P < .001).

CONCLUSION

The current study highlights a potential role cetirizine might have in treating AGA. It should be noted that studies are lacking in this regard and more randomized and controlled trials are warranted in order to confirm or refute such early findings.

A new treatment of alopecia induced by palbociclib: Topical cetirizine

INTRODUCTION

Recently CDK4/6 inhibitors have been introduced for the treatment of hormone positive breast cancer resistant to endocrine therapy. Among their side effects, alopecia is often reported being associated to patients' distress and depressive symptoms.

CASE REPORT

We report the case of a 70-year-old woman affected by breast cancer in treatment with Palbociclib, who developed alopecia.Management and Outcome: We prescribed a topical solution with cetirizine. Global photography, trichoscopy and trichogram were assessed. All evaluations demonstrated alopecia improvement.

DISCUSSION

Currently, no treatment options for CDK 4/6 inhibitors induced alopecia have been proposed. Herein, we report the use of topical cetirizine.

A review of the treatment of male pattern hair loss

Introduction: Androgenetic alopecia is a common hair loss disorder affecting up to 80% of males by the age of 80. It is characterized by androgen related progressive thinning of hair in a defined pattern. It results in diminished self-esteem, reduced confidence and distress in affected men, irrespective of age or stage of baldness. An effective treatment for hair baldness is needed.Areas covered: In androgenetic alopecia, hair follicles undergo progressive miniaturization. Genetic factors and androgens are key role-players in disease pathogenesis. Herein the authors review the pharmacologic treatment of androgenetic alopecia, which involves 5 alpha reductase inhibitors, minoxidil and prostaglandins. Non-pharmacologic approaches are also explored.Expert opinion: Androgenetic alopecia progresses over time and although the current available medical treatments like finasteride and minoxidil are effective in arresting the progression of the disease, they allow only partial regrowth of hair at its best. Early treatment achieves a more optimal outcome. Non-pharmacologic treatments like PRP can be considered in patients refractory to medical treatment.Abbreviations: MPHL: male pattern hair loss; AGA: androgenetic alopecia; DHT: dihydrotestosterone; 5AR: 5-alpha-reductase; VEGF: vascular endothelial growth factor; PG's: prostaglandins (PG's); PGD2R: prostaglandin D2 receptor; VPA: valproic aid; SR: Serenoa Repens; PRP: platelet-rich plasma; PDGF: platelet derived growth factor; TGF: transforming growth factor; ERK: extracellular signal-regulated kinase; PKB: protein kinase B; LLLT: low-level laser therapy; ROS: reactive oxygen species; RCT: randomized control trial; SFRP1: secreted frizzled related protein 1; DP: dermal papilla; PDE5: phosphodiesterase 5.

Physiopathology and current treatments of androgenetic alopecia: Going beyond androgens and anti-androgens

Androgenetic alopecia (AGA) is the most diagnosed hair loss dysfunction. Its physiopathology comprises a genetic predisposition affording an exacerbated response of the hair follicles cells to androgens aggravated by scalp inflammation and extrinsic factors. This paper presents a review of the mechanisms and extrinsic factors involved in the AGA physiopathology as well as its conventional and emerging treatments. The research focused on reports regarding AGA physiopathology and treatments published between January 2001 and July 2019 in medical and related journals. The most used medical treatments for AGA-minoxidil and finasteride-present non satisfactory results in some cases. Currently, the low-level laser therapy is recognized as a safe and effective treatment for AGA. Some minimally invasive techniques-mesotherapy, microneedling, carboxytherapy, and platelet-rich plasma-are also used to stimulate hair growth. Pharmaceutical substances with mechanisms differing from the anti-androgen activity are under current investigation and many of them have botanical origins; however, formulations with higher performance are required, and the hair follicles ability of being a drug and nanoparticle reservoir has been researched. The association of different strategies, that is, substances with synergic mechanisms and the use of advantageous technologies associated with lifestyle changes could improve the treatment outcomes.