Faculty Bibliography

Performance-enhancing drugs, such as testosterone, are used by athletes and youth to increase muscle growth and strength, particularly among males. However, these therapies potentially pose health risks, including liver toxicity, gynecomastia, and hair loss. Testosterone use is rising for performance enhancement, physical appearance, and resistance training, but there remains an absence of standardized guidelines for safe dosages. This study examines the relationship between testosterone use and hair health in males, aiming to develop guidelines for safe, responsible testosterone use. Understanding treatment outcomes in this context is crucial for informed healthcare.

This post-hoc analysis of the ALLEGRO phase 2b/3 study (NCT03732807) evaluated the efficacy and safety of ritlecitinib, an oral Janus kinase 3/TEC family kinase inhibitor, in patients with alopecia totalis (AT) and alopecia universalis (AU). Patients aged ≥ 12 years with alopecia areata (AA) and ≥50% scalp hair loss received once-daily ritlecitinib 50 or 30 mg (± 4-week 200-mg loading dose) or placebo for 24 weeks. In a subsequent 24-week extension period, the ritlecitinib groups continued their doses and patients initially assigned to placebo switched to ritlecitinib (200/50 or 50 mg daily). In this analysis, clinician- and patient-reported hair regrowth outcomes were assessed at weeks 24 and 48 in four AA subgroups: AT/AU, AT, AU, and non-AT/AU. Safety was monitored throughout. Of the 718 randomized patients, 151 (21%) and 147 (20%) were defined as having AT or AU, respectively. At week 24, Severity of Alopecia Tool (SALT) score ≤20 (≤20% scalp hair loss) response rates were higher in the ritlecitinib-treated AT/AU, AT, and AU groups (7%-14%, 7%-21%, and 4%-10%, respectively) vs the placebo group (0% in the AT/AU, AT, and AU groups). The proportions of patients with a SALT score of ≤20 increased through week 48 (AT/AU, 13%-31%; AT, 11%-27%; AU, 6%-41%). Additionally, at week 24, 25%-43%, 32%-42%, and 12%-50% of patients with AT/AU, AT, and AU, respectively, who received ritlecitinib achieved a moderately or greatly improved response based on the Patient Global Impression of Change scale. Response rates generally increased through week 48 and were similar across AA subgroups. In patients with AT/AU, ritlecitinib was well tolerated with a safety profile consistent with that of the overall AA population. Ritlecitinib demonstrated clinical efficacy, patient-reported improvement, and an acceptable safety profile in patients with AT and AU through week 48. A plain language summary of this study is available at https://doi.org/10.25454/pfizer.figshare.26879161. Clinicaltrials.gov: NCT03732807.

All types of alopecia, including androgenetic alopecia, alopecia areata, and lichen planopilaris/frontal fibrosing alopecia, affect over half of men and women. Though a common dermatological experience, many patients with visible hair loss report significant psychological and social distress and, consequently seek treatment. Current existing therapeutic regimens have proven to be efficacious, though may result in various adverse effects and require lifelong use. Laser and light-based therapies have been emerging in the current literature as a safe and alternative treatment, but their utilization for treating alopecia is poorly understood. This review evaluates the existing evidence regarding the use of lasers in the treatment of various forms of alopecia. Overall, there has been promising evidence for potential alopecia treatment efficacy: low-level light therapy for androgenetic alopecia, fractional laser for androgenetic alopecia, and excimer laser for alopecia areata.

Stress may play a key role in alopecia areata (AA), though the exact interactions of stress with AA remain undefined. Corticotropin-releasing hormone (CRH), the proximal regulator of the stress axis, has been recognized as an immunomodulatory factor in tissues and peripheral blood mononuclear cells (PBMCs). We used multicolour flow cytometry to identify receptor CRHR1 expression on PBMC subsets in AA patients (n = 54) and controls (n = 66). We found that CRHR1 was primarily expressed by circulating monocytes. CRHR1 expression on monocytes was enhanced in AA compared with controls (3.17% vs. 1.44%, p = 0.002, chi-squared test). AA incidence was correlated to elevated CD14⁺ monocyte numbers (R = 0.092, p = 0.036) and markedly independently correlated with increased CRHR1 expression (R = 0.215, p = 0.027). High CRHR1 expression was significantly related to chronic AA (disease duration >1 year; p = 0.003, chi-squared test), and large lesion area (AA area >25%; p = 0.049, chi-squared test). We also observed enhanced percentages of active monocytes and reduced CD16⁺ CD3- NK cell numbers in AA patients' PBMCs (p = 0.010; 0.025, respectively). In vitro CRH treatment of PBMCs and human monocyte cell line THP-1 promoted CD86 upregulation. The findings imply that stress-related factors CRH and CRHR1 contribute to AA development and progression where higher CRHR1 expression is associated with chronic AA and larger lesions.