We recently discovered a nonsynonymous variant in the coiled-coil alpha-helical rod protein 1 (CCHCR1) gene within the alopecia areata (AA) risk haplotype. We also reported that the engineered mice with this risk allele exhibited. To investigate more about the involvement of the CCHCR1 gene in AA pathogenesis, we developed an AA model using C57BL/6N cchcr1 gene knockout mice. In this study, mice (6–8 weeks) were divided into two groups: cchcr1^−/− mice and wild-type (WT) littermates. Both groups were subjected to a water avoidance stress (WAS) test. Eight weeks after the WAS test, 25% of cchcr1^−/− mice exhibited non-inflammatory foci of alopecia on the dorsal skin. On the other hand, none of wild-type littermates cause hair loss. The foci resembled human AA in terms of gross morphology, trichoscopic findings and histological findings. Additionally, gene expression microarray analysis of cchcr1^−/− mice revealed abnormalities of hair related genes compared to the control. Our results strongly suggest that CCHCR1 is associated with AA pathogenesis and that cchcr1^−/− mice are a good model for investigating AA.

Aging is associated with altered itch perception, potentially due to changes in neuronal function and pruriceptive signaling. The underlying mechanisms, however, remain unclear. We investigated age-related differences in itch sensitivity at behavioral, cellular, and molecular levels. Young and old mice were intradermally injected with various pruritogens, including small molecules (histamine, chloroquine, and serotonin) and peptides (BAM8–22, AY-NH₂, and SLIGRL-NH₂). Scratching behavior and mechanical itch sensitivity were assessed, and calcium imaging was used to evaluate sensory neuron responses in the dorsal root ganglia. Additionally, immunofluorescence staining was performed to analyze the expression of TRPV1 and Cav3.2. Old mice exhibited reduced scratching behavior following injections, and their neuronal responses to histamine and chloroquine were diminished. Although all treated groups showed increased mechanical alloknesis, the effect was less pronounced in old animals. The expression of TRPV1 and Cav3.2 was also reduced in dorsal root ganglia neurons of old mice. These findings suggest that aging impairs both functional responsiveness and molecular signaling in sensory neurons, contributing to reduced chemical itch sensitivity in aged individuals.

Background/Objectives: Mechanical alloknesis (m-alloknesis), the sensation of itch evoked by normally non-pruritic mechanical stimuli, is commonly observed in dry skin-associated conditions, such as xerosis, atopic dermatitis (AD), and psoriasis. Janus kinase (JAK) inhibitors are currently used to treat AD and suppress inflammation and itch. However, their specific roles in the modulation of m-alloknesis remain unclear. Therefore, in this study, we investigated the effects of various oral JAK inhibitors on m-alloknesis using a murine model of AD. Methods: An AD-like phenotype was induced in mice through the repeated topical application of an ointment containing Dermatophagoides farinae (house dust mite) extract. The mice were then orally treated with one of three JAK inhibitors: the JAK1/2 inhibitor baricitinib, the JAK1-selective inhibitor abrocitinib, or the JAK2-selective inhibitor AZ960. M-alloknesis was evaluated by quantifying scratching behavior in response to 30 controlled mechanical stimuli applied to lesional skin. Results: The JAK inhibitor treatments did not affect skin barrier integrity, dermatitis severity, or spontaneous scratching behavior. However, baricitinib and abrocitinib significantly reduced m-alloknesis scores, whereas AZ960 had no effect. Conclusions: These results suggest that JAK1 signaling plays a critical role in the induction of m-alloknesis in AD. Selective JAK1 inhibition is a promising therapeutic strategy for attenuating m-alloknesis and improving quality of life for patients with AD, independent of general skin inflammation and barrier function.

Background: Thread lifting has emerged as a minimally invasive alternative to surgical facial rejuvenation, providing mechanical tissue repositioning with shorter recovery times. Advances in biomaterials and thread design have improved safety and lifting capacity; however, variability in clinical outcomes persists due to differences in vector design, thread type, tissue manipulation, and anesthesia techniques. These factors may influence complication rates, procedural tolerance, and postoperative downtime, contributing to ongoing concerns regarding the predictability and reproducibility of thread-lifting procedures. Objective: To describe the development of a vector-optimized thread-lifting technique (VectorLift) and to compare its clinical performance in an exploratory, real-world, non-randomized comparative study with two commonly used thread-lifting approaches employing different biomaterials and insertion methods. Methods: The VectorLift protocol was developed using anatomically guided vector placement, ligament-oriented reinforcement, and optimized local anesthetic infiltration. Over a three-year period, 44 female patients (mean age 47 years) underwent facial thread-lifting procedures. Eighteen patients were treated using the proposed technique with cannulated polydioxanone (PDO) threads, while the remaining patients were treated with either double-needle poly-L-lactic acid (PLA) plus poly(L-lactide-co-glycolide) (PLGA) cone threads or cannulated PLA/polycaprolactone (PCL) threads. Clinical outcomes included recovery time (days of downtime), intraoperative pain levels, patient satisfaction measured using the FACE-Q scale before treatment and two weeks post-procedure, and complication rates including dimpling, bruising, edema, and transient asymmetry. Standardized clinical photographs were obtained before and immediately after treatment. Results: VectorLift was associated with lower reported intraoperative pain, shorter recovery time and lower rates of early postoperative complications compared with the other techniques, while patient satisfaction scores were comparable among groups. Immediate photographic assessment confirmed visible aesthetic improvement without overcorrection. Conclusion: VectorLift is an anatomically guided thread-lifting technique that, in this real-world non-randomized comparative study, was associated with improved procedural tolerance and shorter postoperative downtime while maintaining high patient satisfaction and effective aesthetic outcomes. Further controlled studies with larger patient populations and longer follow-up periods are warranted to confirm these findings.

Chronic pruritus (or itch) is a common condition associated with aging; however, the neural mechanisms driving age‐related itch hypersensitivity remain largely unknown. Here, we investigated the role of serotonergic signaling in modulating itch sensitivity during aging. Aged mice exhibited enhanced mechanical alloknesis without changes in spontaneous scratching behavior, indicating that aging selectively affects mechanically evoked itch. Consistent with this phenotype, aged mice showed elevated urinary serotonin levels and increased expression of the serotonin receptor 5‐HT ₇ in dorsal root ganglion neurons and the spinal dorsal horn. Pharmacological blockade of 5‐HT ₇ receptors attenuated itch‐related behaviors, particularly mechanical alloknesis, indicating that serotonergic remodeling contributes to age‐related itch hypersensitivity. These findings identify spinal 5‐HT ₇ signaling as a potential therapeutic target for chronic pruritus in older individuals.

Purpose: Laser-assisted skin regeneration is a cornerstone of modern dermatologic practice; however, post-inflammatory hyperpigmentation (PIH) remains a major limiting complication of CO₂ laser treatments. Risk has traditionally been attributed to darker phototypes, particularly in high ultraviolet (UV) exposure settings. Emerging evidence suggests that metabolic factors, especially insulin resistance measured by HOMA-IR, may influence pigmentary responses. This study evaluated a Dual Technique CO₂ laser protocol designed to enhance skin regeneration while reducing the number of treatment sessions and explored the association between PIH and metabolic status. Patients and Methods: A prospective, non-randomized, real-world study included 45 patients treated in a private practice in the Maghreb region, characterized by high UV exposure and predominantly medium-to-high phototypes. The Dual Technique combined ablative fractional vaporization with subablative thermal stimulation. Skin quality was assessed using the Vancouver Scar Scale (VSS), and PIH severity using the Dermal Pigmentation Area and Severity Index (DPASI). Outcomes were analyzed in relation to phototype, HOMA-IR, and polycystic ovary syndrome (PCOS). Results: Significant clinical improvement was observed across indications following treatment, typically within two sessions. PIH occurred in 15/20 (75%) patients with Fitzpatrick phototypes I–III compared with 9/25 (36%) patients with phototypes IV–VI (p = 0.0092). PIH severity showed a strong positive correlation with HOMA-IR (Spearman ρ = 0.8624, p < 0.0001). PCOS prevalence did not differ significantly between phototype groups (p = 0.8). PIH improved significantly following standardized management. Conclusion: The Dual Technique CO₂ laser protocol was associated with favorable clinical outcomes using relatively few treatment sessions. In this cohort, higher HOMA-IR was strongly associated with greater PIH severity, suggesting that insulin resistance may represent an additional factor associated with individual PIH susceptibility. These findings are hypothesis-generating and require confirmation in larger, controlled studies before metabolic assessment can be recommended for routine laser-treatment risk stratification.