Juan Jimenez-Cauhe

Introduction Androgenetic alopecia (AGA) is a common condition in transgender and gender-diverse (TGD) individuals and may have an important psychosocial impact by exacerbating gender dysphoria and impairing quality of life. Hair loss patterns and treatment considerations in this population are influenced by genetic predisposition, cumulative androgen exposure, and the use of gender-affirming hormone therapy (GAHT). However, evidence-based guidance for the management of AGA in TGD individuals remains limited. Methods A narrative review of the literature was conducted using PubMed, Embase, Cochrane, and ClinicalTrials.gov from database inception to 1 January 2026. Publications addressing the epidemiology, pathophysiology, clinical presentation, and management of AGA in TGD individuals were included. Evidence from cisgender populations was considered when TGD-specific data were lacking. Recommendations were formulated on the basis of available evidence and authors’ clinical experience (dermatologists and endocrinologists). Results AGA in transgender men (TM) most frequently develops after initiation of masculinizing GAHT and follows a clinical course similar to cisgender men, whereas in transgender women (TW) it often reflects prior androgen exposure and may stabilize with feminizing GAHT. Oral minoxidil has emerged as a promising therapeutic option across TGD populations owing to its favorable efficacy and safety profile. Dosing should be individualized according to therapeutic goals, including scalp hair regrowth and, when desired, enhancement of beard or body hair. Higher doses may be carefully considered in select TM. The role of 5-alpha-reductase inhibitors appears more relevant in TM, while their benefit in TW with suppressed testosterone levels remains uncertain. Adjunctive therapies such as topical agents, mesotherapy with dutasteride, low-level laser therapy, platelet-rich plasma, and hair transplantation may complement medical treatment. Conclusions AGA should be regarded as a clinically significant condition in TGD individuals rather than a purely cosmetic concern. Management requires an individualized, goal-oriented, and gender-affirming approach, with oral minoxidil representing a cornerstone of therapy. Given the limited high-quality evidence, further prospective studies are needed to define optimal treatment algorithms and long-term outcomes in this population.

Introduction: Trichoteiromania is a friction-induced hair shaft disorder caused by repetitive rubbing/scratching and is often considered the hair shaft expression of lichen simplex chronicus (“scratching-pseudo-alopecia”). It is classically described on the scalp and presents with lichenified plaques and characteristic trichoscopy such as broom hairs and V-hairs. Pruritus or an urge to rub is common and may help distinguish it from trichotillomania (hair pulling), which is often asymptomatic. To date, the condition has been described almost exclusively as a scalp disorder. Case Presentation: We report a 55-year-old man working in finance with a 15-year history of asymptomatic skin changes on the dorsal hands, initially unilateral and later bilateral, who was referred because of concern about malignancy. Examination revealed symmetric lichenified plaques with excoriations, erythema, haemorrhagic crusts, and numerous short broken hairs on the dorsal aspects of the index fingers and thumb, as well as bilateral enlarged lunulae of the thumbnails. Trichoscopy was diagnostic, showing broom hairs, V-shaped hairs, short broken hairs at different lengths, perifollicular and interfollicular scale, and irregular perifollicular brown pigmentation, consistent with trichoteiromania. No biopsy was required. The patient was reassured regarding the benign nature of the condition, started on topical urea and clobetasol, and referred for psychiatric follow-up to address the underlying compulsive rubbing behaviour. Conclusion: This case represents, to our knowledge, the first description of trichoteiromania affecting a non-scalp site and demonstrates that its full trichoscopic signature can occur on extracranial hair-bearing skin. This case expands the anatomical spectrum of trichoteiromania beyond the scalp and highlights trichoscopy as a rapid, non-invasive tool to attribute hair shaft damage to chronic friction.

Introduction: Onychotillomania is a body-focused repetitive behavior disorder characterized by compulsive trauma to the nail unit. While manual manipulation is well recognized, oral-induced mechanisms remain undocumented. We describe a novel subset involving frictional trauma from the teeth, which we term onychotillomania dentata. Case Presentation: An 11-year-old female presented with a 1-year history of progressive thumbnail dystrophy. Clinical history revealed a habitual behavior occurring predominantly at night: inserting the thumbs into the mouth and rubbing the nail plates against the lower incisors in a repetitive anteroposterior motion. The patient described the behavior as soothing and unconscious. Signs of concomitant onychophagia were also present. Examination demonstrated central nail plate concavity, lamellar splitting, periungual erythema, and localized subungual hyperkeratosis. Dermoscopy revealed lamellar onychoschizia, linear furrows, and compact subungual debris. Behavioral counseling was initiated, including thumb guards during sleep and positive reinforcement strategies. Oral n-acetylcysteine (600 mg every 12 h) was prescribed as adjunctive therapy. Referral to pediatric psychodermatology was recommended for behavioral assessment and initiation of habit-reversal training. Conclusion: Onychotillomania dentata represents a previously undescribed pattern of nail trauma within the broader spectrum of onychotillomania. While classical onychotillomania typically results from manual manipulation, onychotillomania dentata is distinguished by repetitive oro-digital friction. Clinical features include central concavity, lamellar splitting, and linear furrows along the axis of mechanical trauma. Diagnosis often relies heavily on clinical morphology and dermoscopy, especially as many patients may deny their behavioral habit. Early recognition is crucial to avoid misdiagnosis and unnecessary treatment. Additionally, chronic mechanical friction may pose a risk of dental damage, including enamel erosion. Management involves behavioral modification strategies, pharmacologic support when appropriate, and interdisciplinary psychodermatologic care.

Low-dose oral minoxidil (LDOM) has emerged as a widely used off-label treatment for different types of alopecia, showing a favorable safety profile and effectiveness. Despite its growing use, it is essential to understand the possible associated adverse events (AEs) and their appropriate management to optimize this therapy. The aim of this article was to comprehensively review the AEs of LDOM treatment, describing their frequency, risk factors, affected anatomical sites, and management strategies. A search in the PubMed and EMBASE databases was performed for studies published before 31 December 2024, reporting the treatment of any type of hair loss with oral minoxidil. The most frequent AE is hypertrichosis, occurring in approximately 15% of patients, with a higher incidence in women and patients with higher doses. Fluid retention affects 1.3–10% of patients, particularly women, and typically occurs within 1–3 months of treatment. Other cardiovascular AEs, such as tachycardia or dizziness, occur in fewer than 5% of cases and are usually mild and transient. Severe AEs, including pericardial effusion, are extremely rare and often linked to compounding errors comprising an excessive dose. Management strategies include dose reduction, pharmacological interventions like diuretics for edema, and lifestyle measures such as sodium restriction. In most cases, AEs resolve without the need for treatment discontinuation. The favorable safety profile of LDOM makes it a valuable therapeutic option for alopecia, though careful patient selection, dose titration, and monitoring are essential to minimize risks.

Background: Androgenetic alopecia (AGA) is common. While topical minoxidil remains the only FDA‐approved therapeutic for AGA, its efficacy is limited in stimulating clinically significant hair regrowth over the longer term. Oral minoxidil, which is used off‐label, is a promising alternative; however, its effectiveness and underlying mechanisms warrant further investigation.Aims: To elucidate the site of action and infer the physiological mechanisms underlying therapeutic responses to oral minoxidil in patients with AGA.Methods: Forty‐one patients with AGA underwent 6 months of low‐dose oral minoxidil treatment. Minoxidil sulfotransferase (SULT) activity was assayed in plucked scalp hair follicles. The primary outcome was hair growth after low‐dose oral minoxidil treatment for a minimum of 6 months, and the secondary outcome was SULT activity in hair follicles.Results: After 6 months of treatment, 26 (63.4%) patients experienced a clinical improvement in alopecia symptoms. The response rate was higher in men (19/26 [73.1%]) than in women (6/15 [40.0%]). Patients with low hair follicle SULT activity demonstrated a higher minoxidil response rate than those with high enzyme activity (85% vs. 43%, p = 0.009).Conclusions: Our findings indicate that low SULT activity within the hair follicles is associated with a favorable response to oral minoxidil therapy in patients with AGA. Further elucidation of the underlying mechanisms could significantly improve personalized therapeutic approaches through improved patient selection and the rational design of adjuvant treatments.