Poonkiat Suchonwanit

Leukotrichia refers to whitening or depigmentation of hair resulting from reduced or absent melanin in the hair shaft. Although often considered a cosmetic finding, it may reflect underlying alterations in follicular melanocyte biology and therefore have diagnostic, prognostic, and therapeutic relevance. The clinical spectrum includes congenital and genetic disorders, including piebaldism, Waardenburg syndrome, tuberous sclerosis complex, and pigment dilution syndromes; autoimmune and inflammatory conditions, including vitiligo and follicular vitiligo, alopecia areata, and Vogt–Koyanagi–Harada disease; nevus- and melanoma-associated immune phenomena; drug-induced changes; and postinflammatory, traumatic, laser-associated, and idiopathic types. This narrative review, based on a structured literature search of biomedical databases, summarizes current evidence on terminology, follicular biology, mechanisms, etiologic spectrum, diagnostic approach, management, and prognosis of leukotrichia. Leukotrichia is best regarded as a final manifestation of diverse mechanisms, including congenital absence of melanocytes, immune-mediated melanocyte destruction, collapse of follicular immune privilege, melanocyte stem cell depletion, functional inhibition of melanogenesis, and structural injury to the follicular pigmentary unit. In vitiligo, hair depigmentation may indicate depletion of the follicular melanocyte reservoir and has been associated with a poorer response to medical and phototherapeutic interventions. In other settings, it may reflect stable developmental absence or structural injury with limited potential for repigmentation. Management is primarily cause-directed, and hair repigmentation should be evaluated separately from surrounding skin repigmentation in both clinical practice and research. Key priorities include standardization of terminology, development of specific outcome measures, independent reporting of hair and skin responses, and identification of predictive biomarkers for restoration of follicular pigmentation.

1. Alopecia areata (AA) is a chronic, immune-mediated, nonscarring hair disorder with a clinical spectrum ranging from limited patchy disease to alopecia totalis and alopecia universalis [1,2]. Alt...

Background: Western studies have reported associations between facial wrinkling and chronic obstructive pulmonary disease (COPD), suggesting a shared susceptibility to tissue aging. However, data on Asian populations are limited, and population-specific differences in skin biology may modify these relationships. Objective: To investigate the association between facial wrinkle severity and COPD characteristics in Thai patients and to identify independent predictors of wrinkle severity. Methods: This cross-sectional study enrolled 93 Thai patients with COPD. Facial wrinkles were assessed using the Daniell grading scale (a validated six-point subjective clinical grading system) and the Antera 3D imaging system (an objective three-dimensional topographic imaging device). Multivariable linear and logistic regression analyses were performed to identify independent predictors of wrinkle severity after adjustment for age, sex, body mass index (BMI), cumulative smoking exposure, occupational sun exposure, and post-bronchodilator FEV₁ % predicted. Results: Mean age was 72.6± 8.8 years (90.3% male). Severe facial wrinkling, defined as a Daniell score ≥ 4, was present in 41.9% of the patients. The Daniell grading scale and Antera 3D measurements showed a moderate-to-strong correlation (Spearman’s ρ=0.68, p< 0.001). In multivariable analyses, age was consistently associated with both objective wrinkle depth (β=0.08; 95% CI: 0.01– 0.24; p=0.042) and severe wrinkling (OR=1.15; 95% CI: 1.06– 1.23; p< 0.001). Higher body mass index was inversely associated with objective wrinkle severity (β=− 0.34; 95% CI: − 0.65 to − 0.03; p=0.031) but not with severe Daniell-grade wrinkling. COPD-related characteristics, including FEV₁ % predicted, cumulative smoking exposure, and smoking-related COPD status, showed no significant associations with wrinkle severity after adjustment. Conclusion: Among Thai patients with spirometry-confirmed COPD, no significant association was detected between facial wrinkle severity and the COPD-related characteristics assessed. Age was the most consistent independent predictor of wrinkle severity, while higher BMI showed an inverse association with objective wrinkle measurements only. These findings differ from those reported in Western populations and support population-specific validation before applying facial wrinkling as a cutaneous marker of COPD-related disease burden.

Facial hair development is a crucial aspect of gender affirmation for transgender men. Despite testosterone therapy, incomplete facial hair growth remains a common concern. This randomized, double-blind, placebo-controlled trial evaluated topical 3% minoxidil for facial hair enhancement in 69 transgender men on stable gender-affirming hormone therapy (GAHT). This randomized, double-blind, placebo-controlled trial enrolled 69 transgender men on stable GAHT, registered on the Thai Clinical Trials Registry (TCTR20220205004). Participants were randomized 1:1 to receive topical 3% minoxidil or vehicle placebo twice daily for 12 weeks. Primary outcomes were changes in hair density and diameter assessed via videodermoscopy. Secondary outcomes included modified Ferriman-Gallwey Score (mFGS), Dermatology Life Quality Index (DLQI), and patient satisfaction. The minoxidil group (n = 34) demonstrated significant improvements versus placebo (n = 35) in beard density (11.16 vs. 0.08 hairs/cm², p = 0.01), beard diameter (5.37 vs. -0.33 μm, p = 0.01), mustache density (18.45 vs. 1.74 hairs/cm², p = 0.003), and mustache diameter (4.83 vs. 1.31 μm, p = 0.008). Physician and patient-assessed mFGS showed significant improvements with minoxidil (p < 0.05). Quality of life improved markedly (median DLQI: 5 to 1.5 vs. 4 to 3, p < 0.05), with higher patient satisfaction scores (8.16 vs. 5.36, p < 0.001). Adverse events were minimal and comparable between groups. Topical 3% minoxidil represents an effective, safe, and well-tolerated adjunctive treatment for facial hair enhancement in transgender men receiving GAHT.

Background: Alopecia areata (AA) affects all ages, genders, and ethnicities. AA severely impacts patients' quality of life. Treatments indicated for AA have only been approved since 2022/2023. While some Asia Pacific (APAC) countries/regions have national or regional guidelines, many lack AA‐specific guidance or have not updated existing guidelines to incorporate recently approved treatments. Methods: To better inform treatment decisions, 18 dermatologists from Australia, China, India, Korea, Malaysia, Singapore, Taiwan, and Thailand completed a three‐round Delphi‐based consensus process involving survey completion, open discussion, and statement voting. A consensus for Likert‐type and multiple‐choice statements was defined as ≥ 70% agreement or disagreement. Results: Consensus was achieved on 140 statements. The panel recognizes that AA is clinically heterogeneous and imposes a considerable burden on patients and their families. Trichoscopy is deemed essential for diagnosing and monitoring AA, while skin biopsy is reserved for when the cause of hair loss is unclear. In terms of disease severity, moderate AA is defined as 21%–49% hair loss and severe AA as ≥ 50% hair loss. Regarding treatment, topical corticosteroids are recommended in children < 12 years. For patients aged ≥ 12 years, topical and intralesional corticosteroids could be used for mild‐to‐moderate AA, while Janus kinase inhibitors and systemic corticosteroids have a role in moderate‐to‐severe AA. Adjuvant minoxidil could also be used in chronic AA. Conclusions: This modified Delphi‐based consensus provides a practical, region‐focused framework to standardize the diagnosis and management of AA across diverse APAC healthcare settings in hope of improving patient outcomes.

Actinic prurigo (AP) is a rare photodermatosis with variable clinical presentations across different ethnic populations. While lip involvement is common in Latin American populations, isolated cheilitis as the sole manifestation in elderly Asian patients has not been previously documented. We report a 67-year-old Thai female presenting with chronic, recurrent painful ulcers on the lower lip persisting for six months. Despite multiple treatments at a private clinic, new lesions continued to develop. Dermatological examination revealed multiple erosions on an erythematous, edematous plaque at the vermilion border of the lower lip. Histopathological examination demonstrated dense lymphocytic infiltration with well-defined lymphoid follicles, demonstrating the histopathological pattern of follicular cheilitis, which is pathognomonic for actinic prurigo cheilitis. Interestingly, phototesting and photoprovocation yielded normal results across all UV spectra. Complete remission was achieved after two months of treatment with topical 1.25% hydrocortisone cream combined with strict sun protection measures. This case highlights an unusual phenotype of actinic prurigo in an Asian patient, characterized by isolated lip involvement in the absence of other cutaneous manifestations. It underscores the importance of considering AP in the differential diagnosis of chronic lip lesions, even in atypical demographics and with normal phototesting results. The favorable response to conservative management emphasizes the value of early recognition and appropriate treatment.

Female pattern hair loss (FPHL) and fibrosing alopecia in a pattern distribution (FAPD) share similar clinical presentations but differ fundamentally in pathophysiology and management. Reliable, noninvasive trichoscopic criteria to distinguish these entities remain inadequately defined. This prospective cross‐sectional study enrolled 63 consecutive women with biopsy‐confirmed patterned alopecia (21 FAPD and 42 FPHL), matched for hair loss severity using the Sinclair scale, to compare clinical and trichoscopic features and develop a hierarchical diagnostic algorithm. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC) were calculated with 95% confidence intervals. Loss of follicular ostia was identified in all FAPD cases, but only 2.4% of FPHL cases (AUC 0.99), and white fibrotic patches occurred exclusively in FAPD (47.6%), while yellow dots were found only in FPHL (83.3%). Vellus hairs > 10% were significantly less frequent in FAPD than FPHL (47.6% vs. 95.2%), reflecting a relative vellus hair depletion, termed the “vellus paradox,” likely caused by preferential destruction of miniaturized follicles by the lichenoid inflammatory process. FAPD patients also had shorter disease duration and more frequent scalp symptoms, including burning sensation and tenderness. A hierarchical two‐step trichoscopic algorithm using specificity‐based rule‐in (loss of follicular ostia or white fibrotic patches) and sensitivity‐based rule‐out heuristics (hair diameter diversity or vellus proportion) achieved 100% sensitivity, 97.6% specificity, and 98.4% overall accuracy (AUC 0.99) for identifying FAPD. Distinct trichoscopic features, particularly loss of follicular ostia, white fibrotic patches, and relative vellus hair depletion, reliably differentiate FAPD from FPHL. The proposed algorithm enables rapid, noninvasive bedside diagnosis in this derivation cohort; external validation is required before routine implementation.

Background: Fibrosing alopecia in a pattern distribution (FAPD) is a lymphocytic primary cicatricial alopecia first described in 2000. However, to date, the FAPD literature remains sparse. Objectives: To identify clinicopathological features and treatment outcomes of FAPD in a large multicentre cohort. Methods: Patients who had biopsy-proven FAPD were selected from nine specialist hair clinics and were reviewed retrospectively to evaluate the clinical pattern of hair loss, trichoscopic and histopathological features, and response to treatment. Results: Of 110 patients, with a mean age of onset of 52.5 (SD 14.8) years, 94 (85.5%) were women. The most common trichoscopic findings were loss of follicular ostia (97.2%, 103/106) and anisotrichia (97%, 84/87). Histopathological examination revealed perifollicular lymphocytic infiltration in 96.1% (99/103) and concentric lamellar fibrosis in 97% (92/95). After a median duration of treatment of 24 [interquartile range (IQR) 13–50] months, there was stabilization in hair density [median Sinclair grade 3.0 (IQR 3.0–4.0) pretreatment vs. 3.0 (IQR 2.0–4.0) post-treatment, P = 0.62]. Out of the 42 patients who received treatment for ≥ 12 months, 23 achieved stabilization and 16 demonstrated improvement in hair density. Conclusions: Limitations of the study include its retrospective design and disparate treatments. FAPD may be prone to misdiagnosis because of overlapping clinicopathological features with androgenetic alopecia. A combination of anti-inflammatory (for example, topical corticosteroids) and hair growth-promoting agents (for example, topical or low-dose oral minoxidil) can stabilize the condition or even promote hair regrowth.

Background: As the incidence of frontal fibrosing alopecia (FFA) continues to rise, there is a need for an optimal treatment algorithm for FFA. Objectives: To produce an international consensus statement on the treatment modalities and prognostic indicators of FFA. Methods: Sixty‐nine hair experts from six continents were invited to participate in a three‐round Delphi process. The final stage was held as a virtual meeting facilitated via Zoom. The consensus threshold was set at ≥66%. Results: Of 365 questions, expert consensus was achieved in 204 (56%) questions following completion of the three rounds. Three additional questions were included at the final meeting. The category with the strongest consensus agreement was disease monitoring (9; 100%). Questions pertaining to physical therapies achieved the least category consensus (15; 40%), followed by systemic therapy (45; 43%). Limitations: The study lacked sufficient representation from Africa and South America. Conclusions: SOFFIA highlights areas of agreement and disagreement among experts. Robust research is warranted to provide evidence‐based treatment recommendations.

Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is a rare dermatological disorder with fewer than 100 reported cases. It is characterized by abnormal keratinization over the dilated acrosyringium, and is hypothesized to involve somatic mosaicism of the GJB2 gene. Typically presenting in early childhood with linearly distributed hyperkeratotic papules along the Blaschko line, PEODDN predominantly affects palms and soles. We report an atypical case of PEODDN in a 64-year-old woman who presented with an asymptomatic solitary nodule on her left foot that had been present for three months. Histopathological examination confirmed the diagnosis and revealed a characteristic cornoid lamella overlying the dilated acrosyringium. The lesion was successfully treated with a CO₂ laser, with complete resolution and no recurrence at one-month follow-up. This case highlights the importance of considering PEODDN in the differential diagnosis of solitary lesion in atypical locations, even in older adults, and contributes to the limited literature on the late-onset solitary presentation of this rare condition. Our comprehensive review of the literature provides insights into the pathogenesis, clinical variations, associated conditions, and treatment options of PEODDN, with the aim of guiding clinicians in managing this uncommon entity.