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Journal of Cosmetic Dermatology Sep 2023Exosomes are small extracellular vesicles with potential roles in modulating the hair growth cycle and are an emerging therapy for patients with alopecia. In recent... (Review)
Review
BACKGROUND
Exosomes are small extracellular vesicles with potential roles in modulating the hair growth cycle and are an emerging therapy for patients with alopecia. In recent years, researchers have made significant progress in deciphering the network of cellular interactions and signaling pathways mediated by the transfer of exosomes. This has opened the door to a wide range of potential therapeutic applications with an increasing focus on its application in precision medicine.
AIM
To evaluate current published evidence, both preclinical and clinical, on the use of exosomes for hair restoration.
METHODS
In January 2023, a systematic search was conducted using PubMed, Embase, and the Cochrane Library. Records were identified, screened, and assessed for eligibility as per the PRISMA guideline.
RESULTS
We identified 16 studies (15 preclinical and 1 clinical) showing varying degrees of efficacy using exosomes derived from sources including adipose-derived stem cells (ADSCs) and dermal papilla cells (DPCs). Applications of exosomes isolated from ADSCs (ADSC-Exo) and DPCs have shown early promising results in preclinical studies corroborated by results obtained from different model systems. Topical ADSC-Exo has been tried successfully in 39 androgenetic alopecia patients demonstrating significant increases in hair density and thickness. No significant adverse reactions associated with exosome treatment have been reported thus far.
CONCLUSIONS
Although current clinical evidence supporting the use of exosome treatment is limited, there is a growing body of evidence suggesting its therapeutic potential. Further studies are warranted to define its mechanism of action, optimize its delivery and efficacy, and to address important safety concerns.
Topics: Humans; Exosomes; Adipose Tissue; Hair; Adipocytes; Alopecia
PubMed: 37381168
DOI: 10.1111/jocd.15869 -
Journal of the American Academy of... Mar 2020Alopecia areata (AA) is a common autoimmune alopecia with heterogeneous severity and distribution. Previous studies found conflicting results about AA epidemiology. (Meta-Analysis)
Meta-Analysis
BACKGROUND
Alopecia areata (AA) is a common autoimmune alopecia with heterogeneous severity and distribution. Previous studies found conflicting results about AA epidemiology.
OBJECTIVE
To determine the prevalence, incidence, and predictors of AA, alopecia totalis, alopecia ophiasis, and alopecia universalis.
METHODS
A systematic review of all published cohort and cross-sectional studies that analyzed AA and its subtypes. MEDLINE, Embase, LILACS, Scopus, Cochrane Library, and GREAT were searched. At least 2 reviewers performed study title/abstract review and data extraction. Random-effects meta-analysis was used because of significant heterogeneity (I = 99.97%).
RESULTS
Ninety-four studies met the inclusion criteria. The pooled prevalence (95% confidence interval, N) of AA overall was 2.11% (1.82-2.42, N = 302,157,365), with differences of population-based (0.75% [0.49-1.06%], N = 301,173,403) and clinic-based (3.47% [3.01-3.96], N = 983,962) studies. The prevalences of alopecia totalis, ophiasis, and universalis were 0.08% (0.04-0.13, N = 1,088,149), 0.02% (0.00-0.06, N = 1,075,203), and 0.03% (0.01-0.06, N = 1,085,444), respectively. AA prevalence (95% confidence interval) increased over time (<2000: 1.02% [0.85-1.22]; 2000-2009: 1.76% [1.51-2.03]; >2009: 3.22% [2.59-3.92]; P < .0001) and differed by region. AA prevalence was significantly lower in adults (1.47% [1.18-1.80]) than children (1.92% [1.31-2.65]; P < .0001).
CONCLUSIONS
AA affects 2% of the global population. AA prevalence is lower in adults than children, is increasing over time, and significantly differs by region.
Topics: Alopecia; Alopecia Areata; Humans; Incidence; Prevalence
PubMed: 31437543
DOI: 10.1016/j.jaad.2019.08.032 -
The Journal of Dermatology Jan 2022Trichoscopy represents a non-invasive diagnostic modality widely used in daily practice. Despite the common perception that this technique has been fairly established,... (Review)
Review
Trichoscopy represents a non-invasive diagnostic modality widely used in daily practice. Despite the common perception that this technique has been fairly established, some key issues remain to be addressed. Complexity and inconsistency in terminology in past literature are likely to confuse investigators when they are recording, reporting, and retrieving the findings. In addition, a diagnostic algorithm adopting sufficiently integrated and updated findings is not readily available. By adopting a systematic review approach, this review attempted to redefine major trichoscopic findings and integrate their synonyms individually into the most frequently used terms besides identifying and discussing terms which potentially cause confusion. The findings are categorized into five subgroups: hair shaft, follicular, perifollicular, scalp findings, and hair distribution pattern abnormalities. The calculation of sensitivities and positive predictive values of such redefined findings was conducted by reviewing the descriptions in the past literature on major hair diseases, including alopecia areata, androgenetic alopecia/female pattern hair loss, telogen effluvium, trichotillomania, lichen planopilaris, frontal fibrosing alopecia, central centrifugal cicatricial alopecia, discoid lupus erythematosus, folliculitis decalvans, tinea capitis, and dissecting cellulitis, to confirm the diagnostically meaningful findings for representative diseases. This attempt redefined, for instance, yellow dots, short vellus hairs, exclamation mark hairs, black dots, and broken hairs as the findings of diagnostic significance for alopecia areata and hair diameter diversity, peripilar sign, and focal atrichia for androgenetic alopecia/female pattern hair loss. An updated diagnostic flowchart is proposed with the instructions to maximize its usefulness. Current limitations and future perspectives of trichoscopy as well as other emerging non-invasive diagnostic modalities for hair diseases are also discussed.
Topics: Alopecia; Alopecia Areata; Dermoscopy; Female; Hair; Hair Diseases; Humans; Software Design
PubMed: 34806223
DOI: 10.1111/1346-8138.16233 -
Journal of the American Academy of... Jun 2023The diagnosis and treatment of medication-associated alopecia often challenges patients and physicians. While numerous studies on the topic exist, limited information on... (Review)
Review
BACKGROUND
The diagnosis and treatment of medication-associated alopecia often challenges patients and physicians. While numerous studies on the topic exist, limited information on the strength and magnitude of these studies exists.
OBJECTIVES
We investigated the most commonly prescribed medications with high levels of evidence to support associations with alopecia.
METHODS
A list of most commonly prescribed medications was compiled using the "Top 100 Prescriptions, Sales" (Intercontinental Marketing Services) and "Top 200 Names Searched" (RxList.com). PubMed, Embase, and Web of Science were searched for "generic drug name" AND "alopecia" and "generic drug name" AND "hair loss." Two reviewers independently reviewed articles for drug, study type and level of evidence, and number of alopecia cases.
RESULTS
A total of 192 unique drugs were investigated, with 110 yielding positive search results. Of these, 13 were associated with alopecia in studies with strong levels of evidence (adalimumab, infliximab, budesonide, interferon β-1α, tacrolimus, enoxaparin, zoster vaccine, lamotrigine, docetaxel, capecitabine, erlotinib, imatinib, and bortezomib).
LIMITATIONS
Only full-length articles available in the English language were included. The methodology used relied on lists of drugs based on their sales rather than number of prescriptions, which likely overrepresented expensive drugs.
CONCLUSIONS
Few studies with high levels of evidence have been conducted on the topic of medication-associated alopecia. The mechanisms of hair loss must be further identified to provide effective management.
Topics: Humans; Drugs, Generic; Alopecia; Interferon-beta; Lamotrigine; Research Design
PubMed: 37268392
DOI: 10.1016/j.jaad.2017.01.060 -
JAMA Dermatology Jun 2023
Topics: Humans; Traction; Alopecia
PubMed: 37133879
DOI: 10.1001/jamadermatol.2022.6298 -
Current Problems in Dermatology 2015Scarring alopecia or cicatricial alopecia results from follicular damage that is sufficient to cause the destruction and replacement of pilosebaceous structures by scar... (Review)
Review
Scarring alopecia or cicatricial alopecia results from follicular damage that is sufficient to cause the destruction and replacement of pilosebaceous structures by scar tissue. Primary scarring alopecias represent a group of disorders that primarily affect the hair follicles, as opposed to secondary scarring alopecias, which affect the dermis and secondarily cause follicular destruction. Inflammation may predominantly involve lymphocytes or neutrophils. Cicatricial alopecias that mainly involve lymphocytic inflammation include discoid lupus erythematosus, lichen planopilaris, frontal fibrosing alopecia, central centrifugal alopecia, and pseudopelade (Brocq). Cicatricial alopecias that are due to predominantly neutrophilic inflammation include folliculitis decalvans, tufted folliculitis, and dissecting cellulitis of the scalp. Folliculitis keloidalis is a cicatricial alopecia with a mixed inflammatory infiltrate.
Topics: Acne Keloid; Alopecia; Cellulitis; Cicatrix; Fibrosis; Folliculitis; Humans; Lichen Planus; Lupus Erythematosus, Discoid; Scalp; Scalp Dermatoses; Skin Diseases, Genetic
PubMed: 26370646
DOI: 10.1159/000369407 -
Journal Der Deutschen Dermatologischen... Apr 2018In the classification of the North American Hair Research Society, primary cicatricial alopecias (PCA) are divided into four groups according to their prominent... (Review)
Review
In the classification of the North American Hair Research Society, primary cicatricial alopecias (PCA) are divided into four groups according to their prominent inflammatory infiltrate: PCAs with lymphocytic, neutrophilic, mixed or nonspecific cell inflammation pattern. The hair loss can begin subclinically and progress slowly so that the exact onset of the disease is often difficult to determine. The diagnosis is often delayed. While most forms of cicatricial alopecia can be clearly diagnosed based on clinical presentation in the acute disease stage, diagnosis can be challenging in the subacute, early or late disease stages. At first presentation, a detailed patient history and dermatological examination of the body, including trichoscopy, should be performed. In clinically unclear cases, a biopsy should be performed. Due to the scarcity of primary cicatricial alopecia, there is little evidence on the efficacy of the various therapies. The aims of treatment are to stop or at least delay hair loss and progression of the scarring process, reduce clinical inflammation signs as well as to alleviate subjective symptoms. Hair re-growth in already scarred areas should not be expected. Anti-inflammatory treatment with topical corticosteroids class III to IV and / or with intracutaneous intralesional triamcinolone acetonide injections can be considered in most of the primary cicatricial alopecias. The choice of systemic therapy depends on the type of predominant inflammatory infiltrate and includes antimicrobial, antibiotic or immunomodulating/immunosuppressive agents. Psychological support and camouflage techniques should be offered to the patients.
Topics: Alopecia; Biopsy; Coloring Agents; Combined Modality Therapy; Delayed Diagnosis; Fluorescent Antibody Technique, Direct; Hair Follicle; Humans; Lymphocytes; Neutrophils; Scalp
PubMed: 29645394
DOI: 10.1111/ddg.13498 -
Journal of the American Academy of... Jan 2024Pressure-induced alopecias (PAs) are an infrequent group of scarring and nonscarring alopecias that occur after ischemic obstruction of capillaries that leads to... (Review)
Review
Pressure-induced alopecias (PAs) are an infrequent group of scarring and nonscarring alopecias that occur after ischemic obstruction of capillaries that leads to circumscribed areas of hair loss. Initially described after prolonged surgeries or immobilization, type 1 PA occurs after sustained external pressure to the skin, mainly the scalp prominences. Alopecia induced by cosmetic procedures, referred in this review as type 2 PA, is reported with increased frequency in literature and predominantly emerges from pressure exerted by the volume of injectables. It is important to differentiate type 2 PA from vascular occlusion-induced alopecia because they represent distinct entities. Clinically, PA may present with erythema, swelling, and tenderness; however, alopecia might be the sole manifestation. Crusts and ulceration are associated with a worse outcome and a higher risk of scarring alopecia. Prompt diagnosis is paramount to prevent complications. Trichoscopy, although considered nonspecific, may provide relevant clues for an accurate diagnosis. Hair regrows in most cases, but prognosis depends on ischemia severity and timely treatment with reperfusion therapies or mobilization. Treatment of hair loss is usually not necessary because the disease in most cases is self-limited and reversible. The role of topical minoxidil and corticosteroids remains unknown.
Topics: Humans; Cicatrix; Alopecia; Hair; Scalp; Skin
PubMed: 37454698
DOI: 10.1016/j.jaad.2023.07.009 -
Clinics in Dermatology 2021Frontal fibrosing alopecia (FFA) is a patterned primary cicatricial alopecia that was first described in 1994. Once rare, the incidence of FFA has increased... (Review)
Review
Frontal fibrosing alopecia (FFA) is a patterned primary cicatricial alopecia that was first described in 1994. Once rare, the incidence of FFA has increased dramatically, representing the current most common cause of cicatricial alopecia worldwide. FFA typically begins in postmenopausal women with symmetrical, progressive recession of the frontotemporal hairline together with bilateral loss of the eyebrows. FFA has a distinctive clinical phenotype, which remains a challenge. The histology is identical to lichen planopilaris (LPP), but only a small number of patients have coincidental LPP, usually of the scalp. The vast majority of patients have no evidence of lichen planus elsewhere, and the symmetry and patterned nature of the hair loss are unusual for LPP. Familial cases of FFA are reported, and gene associations have been identified in population studies; however, the pathophysiology remains controversial. Without treatment, FFA is slowly progressive, and although many treatments have been prescribed, the response is often disappointing. We review the pathogenesis, epidemiology, clinical features, histology, and treatment of FFA.
Topics: Alopecia; Cicatrix; Eyebrows; Female; Humans; Lichen Planus; Scalp
PubMed: 34272007
DOI: 10.1016/j.clindermatol.2020.10.007 -
Dermatologic Therapy Jul 2020Αndrogenetic alopecia (AGA) is the most common hair disorder, affecting approximately 50% of men and women. A topical lotion that contains two patented formulas... (Randomized Controlled Trial)
Randomized Controlled Trial
Αndrogenetic alopecia (AGA) is the most common hair disorder, affecting approximately 50% of men and women. A topical lotion that contains two patented formulas (Redensyl and Sepicontrol A5), has been introduced as an alternative approach to standard therapies for AGA. Forty-four patients with AGA were randomized either to apply the active lotion or the vehicle, twice daily for 24 weeks. Subjects were evaluated at 0, 12, and 24 weeks by clinical examination, photographic documentation, quality of life evaluation (DLQI), and trichogram (anagen-to-telogen ratio). Forty-one patients, 18 males and 23 females, completed the study. Among patients receiving active treatment (n = 26), 7.7% had great improvement, 73.1% had moderate improvement, and 19.2% remained stable. The median self-assessment score increased from 4 at baseline to 6 at 24 weeks (P < .001), while the DLQI improved from 4 to 3, respectively (P < .001). The median anagen-to-telogen ratio increased from 2.25 to 4.00 to 6.02 at weeks 0, 12, and 24, respectively. No significant adverse events were reported. This new topical active blend is effective in the treatment of AGA, with high degree of patients' satisfaction, improvement of quality of life, and an excellent safety profile. Thus, it may represent a useful alternative therapeutic approach for AGA.
Topics: Administration, Topical; Alopecia; Female; Hair; Humans; Male; Quality of Life; Treatment Outcome
PubMed: 32473084
DOI: 10.1111/dth.13734