Global, Regional, and National Epidemiology of Alopecia Areata: A Systematic Review and Modelling Study.

BACKGROUND: Alopecia areata (AA) is a chronic autoimmune disease that leads to a high psychiatric, economic, and systemic disease burden. A comprehensive understanding of AA epidemiology is essential for evaluating healthcare source utilization; however, there is a lack of systematic approach for summarizing epidemiologic data on AA. OBJECTIVES: To systematically investigate the global, regional, and national incidence and prevalence of AA. METHODS: A structured search was conducted using the Ovid MEDLINE, EMBASE, Cochrane Library, Web of Science, SciELO, and Korean journal databases from their inception date to October 4, 2023. Studies that reported the prevalence or incidence of AA were included. We used a Bayesian hierarchical linear mixed model to analyse the prevalence estimates. The primary outcomes of our study were the global, regional, and national prevalence of physician-diagnosed AA for overall population, adults, and children. The incidence data were summarised descriptively. RESULTS: In total, 88 studies from 28 countries were included in the analysis. The reported incidence of alopecia areata tended to be higher in adults aged 19-50 years, and this trend was consistent with its estimated prevalence. The reported prevalence in overall population tended to be higher in men compared to in women. The estimated lifetime prevalence of AA was 0.10% (95% credible intervals, 0.03%-0.39%) in the general population worldwide, 0.12% (95% credible intervals, 0.02%-0.52%) in adults, and 0.03% (95% credible intervals, 0.01%-0.12%) in children. The estimated prevalence was highest in the Asian region and lowest in the African region. CONCLUSIONS: In this study, 48% of the total Global Burden of Disease regions had insufficient data reporting the prevalence or incidence of AA. Further studies are needed to provide epidemiological information on middle- and low-income countries. Our study can serve as a crucial reference in terms of healthcare policy decisions.

Prevalence and incidence of comorbid diseases and mortality risk associated with lichen planopilaris: a Korean nationwide population-based study.

BACKGROUND: Various comorbid diseases have been reported in patients with lichen planopilaris (LPP); however, data regarding the risks of incident diseases and mortality are lacking. OBJECTIVES: To investigate the risks of incident diseases and mortality associated with LPP. METHODS: This was a retrospective nationwide population-based study, using data from the National Health Insurance Service Database of Korea from 2002 to 2019. Patients aged ≥ 18 years with three or more documented medical visits for LPP were included. The adjusted hazard ratios (aHRs) for incident disease outcomes and mortality were compared with 1 : 20 age-, sex-, insurance type- and income-level-matched controls. RESULTS: In total, 2026 patients with LPP and 40 520 controls were analysed. The risks of incident systemic lupus erythematosus [aHR 1.91, 95% confidence interval (CI) 1.21-3.03], psoriasis (aHR 3.42, 95% CI 2.83-4.14), rheumatoid arthritis (aHR 1.39, 95% CI 1.19-1.63), lichen planus (aHR, 10.07, 95% CI 7.17-14.15), atopic dermatitis (aHR 2.15, 95% CI 1.90-2.44), allergic rhinitis (aHR 1.29, 95% CI 1.13-1.49), thyroid diseases (hyperthyroidism: aHR 1.42, 95% CI 1.14-1.77, hypothyroidism aHR 1.19 95% CI 1.01-1.41, and thyroiditis: aHR, 1.35, 95% CI 1.08-1.69), nonmelanoma skin cancer (aHR 2.33, 95% CI 1.00-5.44) and vitamin D deficiency (aHR 1.23, 95% CI 1.03-1.47) were higher in patients with LPP. Patients with LPP had a higher mortality rate than controls (aHR 1.30, 95% CI 1.04-1.61), although the risk was not significant after adjusting for comorbidities (aHR 1.08, 95% CI 0.87-1.34). CONCLUSIONS: Patients with LPP had a higher risk of various diseases following LPP diagnosis. Close follow-up is needed to optimize comprehensive patient care.

The Alopecia Areata Consensus of Experts (ACE) study part II: Results of an international expert opinion on diagnosis and laboratory evaluation for alopecia areata.

BACKGROUND: We previously reported the Alopecia Areata Consensus of Experts study, which presented results of an international expert opinion on treatments for alopecia areata. OBJECTIVE: To report the results of the Alopecia Areata Consensus of Experts international expert opinion on diagnosis and laboratory evaluation for alopecia areata. METHODS: Fifty hair experts from 5 continents were invited to participate in a 3-round Delphi process. Consensus threshold was set at greater than or equal to 66%. RESULTS: Of 148 questions, expert consensus was achieved in 82 (55%). Round 1 consensus was achieved in 10 of 148 questions (7%). Round 2 achieved consensus in 47 of 77 questions (61%). The final face-to-face achieved consensus in 25 of 32 questions (78%). Consensus was greatest for laboratory evaluation (12 of 14 questions [86%]), followed by diagnosis (11 of 14 questions [79%]) of alopecia areata. Overall, etiopathogenesis achieved the least category consensus (31 of 68 questions [46%]). LIMITATIONS: The study had low representation from Africa, South America, and Asia. CONCLUSION: There is expert consensus on aspects of epidemiology, etiopathogenesis, clinical features, diagnosis, laboratory evaluation, and prognostic indicators of alopecia areata. The study also highlights areas where future clinical research could be directed to address unresolved hypotheses in alopecia areata patient care.

The Alopecia Areata Consensus of Experts (ACE) study: Results of an international expert opinion on treatments for alopecia areata.

BACKGROUND: A systematic review failed to identify any systemic therapy used in alopecia areata (AA) where use is supported by robust evidence from high-quality randomized controlled trials. OBJECTIVE: To produce an international consensus statement on the use and utility of various treatments for AA. METHODS: Fifty hair experts from 5 continents were invited to participate in a 3-round Delphi process. Agreement of 66% or greater was considered consensus. RESULTS: In the first round, consensus was achieved in 22 of 423 (5%) questions. After a face-to-face meeting in round 3, overall, consensus was achieved for only 130 (33%) treatment-specific questions. There was greater consensus for intralesional treatment of AA (19 [68%]) followed by topical treatment (25 [43%]). Consensus was achieved in 45 (36%) questions pertaining to systemic therapies in AA. The categories with the least consensus were phototherapy and nonprescription therapies. LIMITATIONS: The study included a comprehensive list of systemic treatments for AA but not all treatments used. CONCLUSION: Despite divergent opinions among experts, consensus was achieved on a number of pertinent questions. The concluding statement also highlights areas where expert consensus is lacking and where an international patient registry could enable further research.

Screening of thyroid function and autoantibodies in patients with alopecia areata: A systematic review and meta-analysis.

BACKGROUND: Several studies have reported associations between alopecia areata and diverse thyroid diseases. OBJECTIVE: To investigate the odds ratio and prevalence rate of thyroid dysfunction and autoimmune thyroid diseases in patients with alopecia areata. METHODS: A systematic review of the studies published before March 20, 2018, was performed by using the MEDLINE, Embase, Web of Science, and Cochrane Library databases. The clinical and laboratory findings associated with thyroid dysfunction and autoimmunity were extracted for quantitative analysis. RESULTS: A total of 50 studies were analyzed. Patients with alopecia areata had higher odds of abnormal findings on thyroid function tests, thyroid dysfunction, positive thyroid autoantibodies, and autoimmune thyroid diseases. Moreover, their prevalence rate was much higher than that in the general population. LIMITATIONS: The heterogeneity in baseline characteristics and outcome reporting across the studies. CONCLUSION: Current evidence suggests that thyroid dysfunction and autoimmune thyroid diseases are more prevalent in patients with alopecia areata. Clinicians may be encouraged to screen for the associated signs and symptoms to achieve better outcomes.

Comorbidities in alopecia areata: A systematic review and meta-analysis.

BACKGROUND: Alopecia areata (AA) may be associated with various systemic diseases according to several studies. OBJECTIVE: To identify prevalent and incident diseases in patients with AA and quantify their prevalence and odds and hazard ratios compared with those in controls without AA. METHODS: A systematic review of the studies published before February 28, 2018, was performed by using the MEDLINE, Embase, Web of Science, and Cochrane Library databases. Observational studies on prevalent or incident diseases in patients with AA were included, whereas studies limited to pediatrics or providing only laboratory results or continuous data were excluded. The inverse variance method with a random-effects model was used for meta-analyses. RESULTS: A total of 87 studies were analyzed. Atopic diseases, metabolic syndrome, Helicobacter pylori infection, lupus erythematosus, iron deficiency anemia, thyroid diseases, psychiatric diseases, vitamin D deficiency, and audiologic and ophthalmic abnormalities were more prevalent in patients with AA. Patients with AA had a higher risk of developing autoimmune diseases. LIMITATIONS: Some diseases were investigated by an insufficient number of studies to be meta-analyzed. Meta-analysis of incident diseases was not performed owing to the limited availability of cohort studies. CONCLUSION: AA is associated with various systemic and psychiatric diseases. Physicians are encouraged to evaluate and manage potential comorbid conditions to achieve better outcomes.

Adverse Sexual Effects of Treatment with Finasteride or Dutasteride for Male Androgenetic Alopecia: A Systematic Review and Meta-analysis.

Treatment of male androgenetic alopecia with 5α-reductase inhibitors is efficacious. However, the risk of adverse sexual effects remains controversial. This systematic review and meta-analysis investigated the risk of adverse sexual effects due to treatment of androgenetic alopecia in male patients with finasteride, 1 mg/day, or dutasteride, 0.5 mg/day. Fifteen randomized double-blinded placebo-controlled trials (4,495 subjects) were meta-analysed. Use of 5α-reductase inhibitors carried a 1.57-fold risk of sexual dysfunction (95% confidence interval (95% CI) 1.19-2.08). The relative risk was 1.66 (95% CI 1.20-2.30) for finasteride and 1.37 (95% CI 0.81-2.32) for dutasteride. Both drugs were associated with an increased risk, although the increase was not statistically significant for dutasteride. As studies into dutasteride were limited, further trials are required. It is important that physicians are aware of, and assess, the possibility of sexual dysfunction in patients treated with 5α-reductase inhibitors.

Subclinical sensitization with diphenylcyclopropenone is sufficient for the treatment of alopecia areata: Retrospective analysis of 159 cases.

BACKGROUND: Contact immunotherapy with diphenylcyclopropenone (DPCP) is presently considered the treatment of choice for extensive alopecia areata. However, a major concern with contact immunotherapy is that it causes various adverse effects (AEs) that contribute to discontinuation of treatment. OBJECTIVE: We investigated whether a modified DPCP treatment protocol can promote hair regrowth with fewer AEs. METHODS: All patients were sensitized with 0.1% DPCP and began treatment with 0.01% DPCP. Thereafter, the DPCP concentration was slowly increased according to the treatment response and AEs. This was a retrospective review of DPCP treatment with modified protocols in 159 patients with alopecia areata. RESULTS: Of the 159 patients, 46 (28.9%) showed a complete response and 59 (37.1%) showed a partial response. No patients had AEs after sensitization. During the treatment, only 3 patients (1.9%) showed severe AEs, and 55 showed moderate AEs; however, all were well controlled with antihistamines alone or antihistamines and medium-potency topical steroids. There was no association between treatment response and AEs. LIMITATIONS: Sample size, subject composition, and the retrospective study design represent potential limitations. CONCLUSION: A modified DPCP treatment protocol with subclinical sensitization could induce a favorable therapeutic response and result in fewer AEs.

Long-term utility and durability of the therapeutic effects of bimatoprost 0.03% for eyelash augmentation in healthy Asian subjects.

BACKGROUND: Eyelashes of Asians differ from those of Caucasians in morphology and growth characteristics. Ethnic differences also exist for the tolerability profile of prostaglandin analogues. OBJECTIVE: To evaluate the long-term utility and durability of bimatoprost 0.03% in eyelash augmentation in Asian females. METHODS: One cohort received bimatoprost 0.03% for 36 weeks and another for 20 weeks, with the latter cohort followed for 16 weeks after treatment cessation. The primary endpoint was the percent change in eyelash length at week 20. Secondary measures included percent change in eyelash thickness and darkness, physician's Global Eyelash Assessment and patient satisfaction. RESULTS: At week 20, eyelash length was enhanced in a time-dependent manner, with maximum improvement achieved (19.3%; p < 0.0001). Significant improvements in thickness and darkness were also achieved (22.9%, 6.0%; p < 0.0001). 77.8% of subjects improved by ≥1 grade on Global Eyelash Assessment, with 83.1% satisfied/very satisfied. Improvements were maintained with ongoing treatment to 36 weeks, while these effects were progressively lost with discontinuation. CONCLUSION: Bimatoprost 0.03% safely enhanced eyelashes in Asian females, maintained with ongoing treatment. Cessation of treatment was associated with progressive loss of effects.

The Alopecia Areata Severity and Morbidity Index (ASAMI) Study: Results From a Global Expert Consensus Exercise on Determinants of Alopecia Areata Severity.

Importance: Current measures of alopecia areata (AA) severity, such as the Severity of Alopecia Tool score, do not adequately capture overall disease impact. Objective: To explore factors associated with AA severity beyond scalp hair loss, and to support the development of the Alopecia Areata Severity and Morbidity Index (ASAMI). Evidence Review: A total of 74 hair and scalp disorder specialists from multiple continents were invited to participate in an eDelphi project consisting of 3 survey rounds. The first 2 sessions took place via a text-based web application following the Delphi study design. The final round took place virtually among participants via video conferencing software on April 30, 2022. Findings: Of all invited experts, 64 completed the first survey round (global representation: Africa [4.7%], Asia [9.4%], Australia [14.1%], Europe [43.8%], North America [23.4%], and South America [4.7%]; health care setting: public [20.3%], private [28.1%], and both [51.6%]). A total of 58 specialists completed the second round, and 42 participated in the final video conference meeting. Overall, consensus was achieved in 96 of 107 questions. Several factors, independent of the Severity of Alopecia Tool score, were identified as potentially worsening AA severity outcomes. These factors included a disease duration of 12 months or more, 3 or more relapses, inadequate response to topical or systemic treatments, rapid disease progression, difficulty in cosmetically concealing hair loss, facial hair involvement (eyebrows, eyelashes, and/or beard), nail involvement, impaired quality of life, and a history of anxiety, depression, or suicidal ideation due to or exacerbated by AA. Consensus was reached that the Alopecia Areata Investigator Global Assessment scale adequately classified the severity of scalp hair loss. Conclusions and Relevance: This eDelphi survey study, with consensus among global experts, identified various determinants of AA severity, encompassing not only scalp hair loss but also other outcomes. These findings are expected to facilitate the development of a multicomponent severity tool that endeavors to competently measure disease impact. The findings are also anticipated to aid in identifying candidates for current and emerging systemic treatments. Future research must incorporate the perspectives of patients and the public to assign weight to the domains recognized in this project as associated with AA severity.