Hypertrophic scars (HSs) are a prevalent skin condition that imposes substantial functional, financial, and aesthetic burdens, with existing treatments often leading to recurrence, pain, and adverse effects. To address these issues, we propose a first-in-class fast-dissolving sodium alginate-based microneedle patch (sMN) that achieves sequential, dual-release kinetics by integrating tranilast (TS) and glabridin (GL)-loaded nanoparticles (GLNPs), termed TS+GLNPs@sMN. Our system uniquely integrates rapid TS release for immediate "OFF" switching, suppression of fibroblast activation, stabilization of mast cells, and relief of pruritus, with sustained GL release from GLNPs for prolonged "ON" switching, which promotes fibroblast apoptosis and modulates scar matrix deposition. This sequential "OFF-to-ON" paradigm mirrors the temporal progression of HS pathophysiology, with early inflammatory events preceding fibrotic remodeling. The cone-shaped microneedle patch (~565 μm) demonstrated efficient skin penetration/recovery, even drug distribution, fast dissolution (180 ± 20 s), high loading capacity, and desirable release kinetics. In vitro evaluations confirmed promising anti-proliferative, anti-migratory, and anti-angiogenic effects. Preliminary in vivo biocompatibility in mice was satisfactory, with no skin irritation and normal complete blood count, renal, and hepatic function. In vivo studies in a rabbit ear HS model demonstrate accelerated HS healing, reduced HS thickness, epidermal thickness index (ETI), scar elevation index (SEI), and collagen deposition, along with decreased profibrotic markers, inflammatory cytokines, and angiogenic factors. Overall, the TS+GLNPs@sMN patch offers a minimally invasive, self-administrable, dual-action therapeutic strategy for enhanced HS management, with safety and efficacy in preclinical models.

Ceramide deficiency in the stratum corneum (SC) is a key etiological factor in atopic dermatitis (AD). To clarify the direct role of SC ceramide depletion in impairing SC barrier and water-holding functions and in initiating AD-like skin symptoms and disease-specific molecular alterations, we generated Tg mice overexpressing a mutant form of acid ceramidase (aCDase) under the control of the involucrin promoter, resulting in targeted expression in the upper epidermis. By 3 weeks of age, Tg mice developed noninflammatory, scaly skin characterized by severely compromised barrier integrity and water-holding capacity, along with significantly elevated epidermal aCDase activity and markedly reduced ceramide levels in the SC. Compared to WT controls, Tg mice also exhibited increased epidermal innervation and reduced intraepidermal semaphorin 3a protein levels. Additionally, Tg skin showed substantial changes in the expression of AD-associated biomarkers involved in barrier impairment, pruritus, and Th2 polarization. These included increased levels of Il10, Il17a, S100a7, S100a8, and S100a9 and decreased levels of Cxcl10, Ifng, Il2, Il13, Il33, Sema3a, and Tlr9. Repeated topical application of mite antigens induced allergic responses in Tg mice, but not in WT mice. These responses were characterized by prominent eosinophil infiltration in the dermis and significantly elevated serum IgE levels. Allergen-challenged ear skin from Tg mice also demonstrated significantly increased expression of inflammatory mediators related to AD, including Ccl17, Ccl22, Ccl26, Ccl27, Il3, Il13, Il22, and Il33. These findings establish Tg mice as a pathophysiologically relevant model of AD, presenting key features such as xerotic, pruritic skin, impaired barrier and water-retention functions, and Th2-dominant allergic inflammation. This model provides important insights into ceramide-dependent mechanisms in AD pathogenesis and offers a useful platform for therapeutic development. © 2026 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Although increasingly studied feline otitis externa (OE) prevalence is not yet well defined. The aim of this study was to assess the prevalence of OE in a population of privately owned cats in Northern Italy. Cats were clinically, otoscopically and cytologically evaluated. Diagnosis of OE was based on clinical findings along with abnormal ear cytology. The influence of the main demographic variables was examined. The prevalence of OE was 17% with a positive correlation to being European, and having short hair, a dermatological history, pruritus and multiple clinical signs. Ear cytology was abnormal in 19% of cats. Mites were found in 6% of the cats, about half of which were exclusively indoor cats and completely asymptomatic. Pathological numbers of bacteria and/or yeasts were found on cytology in 15% of cats and, of these, 29% had only Malassezia spp., 65% only cocci, and 6% a mixed population of these microorganisms. The prevalence of OE in owned cats in Northern Italy is relatively high. The identification of parasitic OE in asymptomatic and exclusively indoor cats, and a correlation between OE and dermatological history highlights the importance of systematic ear evaluation as part of routine feline health assessments.

Cerumen, or ear wax, is a naturally occurring substance that is produced at the lateral one-third of the external auditory canal (EAC). Anatomically, this region houses a collection of pilosebaceous glands that includes ceruminous glands, hair follicles, and sebaceous glands. The modified sweat produced by the ceruminous glands has bacteriocidal and fungicidal properties, functioning to lubricate and clean the EAC. As dead skin cells slough off and move out of the ear canal, they combine with the oily secretions of sebaceous glands as well as the modified sweat of the ceruminous glands. The combination of these substances is what makes up cerumen, consisting primarily of dead keratin cells . Cerumen serves as a protective barrier to trap foreign particles. There are a number of pathologies that may present in the EAC including sebaceous cysts, furuncles, and even glandular tumors, but what most commonly plagues patients is the buildup and impaction of cerumen. The American Academy of Otolaryngology defines cerumen impaction as "an accumulation of cerumen that is associated with symptoms, prevents the necessary assessment of the ear, or both" . While cerumen is typically expelled from the EAC spontaneously with the aid of jaw movement, this mechanism may fail some patients and lead to impaction. Impaction is more likely to occur when this normal extrusion of cerumen is prevented in some way; whether that be with the use of hearing aids, persistent use of earplugs/earbuds for noise reduction or music, or by the simply attempting to clean the ears with Q-tips or cotton swabs . Common symptoms include a feeling of fullness in the ear, ear pain or otalgia, itchy ear, the sensation of imbalance, cough, and of course decreased hearing . Roughly 5% of healthy adults, 10% of children, 57% of older persons, and 33% of patients with mental retardation suffer from impaction of cerumen .  Irrigation of the external auditory canal is one of the many options in treating cerumen impaction and a method that is readily available to the likes of general practitioners and emergency rooms. Irrigation may be performed by non-clinicians; resulting in its own advantages/disadvantages and can be attempted alone or with the pre-treatment of a cerumenolytic agent, such as acetic acid, mineral oil, or hydrogen peroxide. It is important to note, however, that a thorough history and physical exam through the use of otoscopy should be obtained to ensure the tympanic membrane (TM) is intact, without perforation or tympanostomy tubes, and to assess for any anatomic abnormalities prior to any irrigation attempts. If multiple attempts to remove impacted cerumen—including a combination of treatments—are ineffective, clinicians should refer the patient to an otolaryngologist.

Respiratory epithelial adenomatoid hamartoma (REAH) represents a category of tumor-like lesion arising from congenital developmental anomalies, characterized by aberrant differentiation or maturational arrest of multiple tissue lineages during embryogenesis. The predominant anatomical site involves the nasal cavity, specifically the nasal septum, with additional potential locations including the middle meatus and ethmoidal sinuses. Definitive diagnosis generally requires histopathological examination. These uncommon nasal neoplasms are amenable to complete excision through endoscopic surgical approaches performed under general anesthesia. A 55-year-old patient with nasal vestibular REAH presented with nasal obstruction, intermittent nasal pruritus, and diminished olfactory function. Clinical examination detected an ovoid mass in the right nasal vestibule, while radiological imaging demonstrated soft tissue density in the corresponding area. The diagnosis of REAH was confirmed through histopathological assessment after complete surgical excision. The patient fortunately experienced no procedure-related complications throughout the perioperative course and follow-up period. Postoperative surveillance through scheduled follow-up examinations is essential to prevent local recurrence.

Prolonged mask use during the COVID-19 pandemic has been associated with an increase in dermatologic conditions, particularly irritant and allergic contact dermatitis. Mechanical friction, occlusion, and humidity contribute to skin barrier disruption and inflammation. Although most cases are self-limiting, a subset may evolve into chronic or steroid-dependent dermatoses. We report a case of a 23-year-old male healthcare professional who developed erythematous plaques behind the ear following continuous mask use. The lesions initially responded to topical betamethasone 0.05% cream but relapsed after tapering, evolving into chronic seborrheic inflammation with pruritus and scaling extending into the scalp and external auditory canal. Application of tacrolimus 0.1% ointment and fusidic acid cream aggravated the condition, reflecting persistent inflammation and barrier dysfunction. Clinical findings indicated steroid dependence and chronic seborrheic-type inflammation. Barrier-restoring measures and cautious corticosteroid withdrawal led to gradual improvement. This case highlights the multifactorial pathogenesis of chronic mask-related dermatitis and underscores the importance of barrier repair, prudent corticosteroid use, and interdisciplinary collaboration in managing persistent cases.

Otitis externa (OE), an inflammation of the external ear canal, is common in both humans and companion animals and often requires prolonged antimicrobial therapy. Ozone has gained attention for its antimicrobial, antiviral, and antioxidant properties in dermatologic disorders, although its optimal dose and route of administration remain unclear. This study aimed to evaluate the efficacy of topical ozone therapy for managing OE compared with conventional antimicrobial treatments. Twenty-seven client-owned dogs with OE were enrolled in an open-label, prospective, controlled clinical trial and assigned to three groups: ozone (Group I), ciprofloxacin drops (Group II), and a veterinary otic solution with florfenicol, terbinafine, and mometasone furoate (Group III). Clinical assessments (OTIS-3, otoscopy, pain, pruritus, cytology) were performed on days 0, 7, 14, and 21, with bacteriological evaluations on days 0 and 21. Based on OTIS-3, treatment success rates were 100 % in Group I, 33.33 % in Group II, and 66.66 % in Group III. Significant improvements in OTIS-3, otoscopy, pain, and pruritus scores were observed in Group I compared to Group II (p < 0.05). Cytological improvement was significant in Groups I (p < 0.001) and III (p = 0.003). Microbiological analysis confirmed the complete absence of bacterial growth in Group I, effectively eliminating Staphylococcus pseudointermedius, Proteus mirabilis, Bacillus spp., Citrobacter braakii, Coagulase-Negative Staphylococci, Escherichia coli, Dermacoccus nishiomiyaensis, and multidrug-resistant Acinetobacter baumannii. These findings highlight the potential of topical ozone therapy as a safe and effective option for the management of otitis externa, with important implications for reducing antimicrobial use and mitigating antimicrobial resistance.