The Rosacea Research Digest from the National Rosacea Society keeps you up to date on recently published basic and clinical research on rosacea, as well as news, reviews, and presentations. It goes out on the last weekday of each month.

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Research

Mites, microbes, and neurodegeneration: A unified environmental hypothesis for Parkinson's disease, Alzheimer's disease, and Lewy body dementia.

Thornton JM, Stevenson JL. J Alzheimers Dis. 2026 Jan 13:13872877251412923. Epub ahead of print. DOI: 10.1177/13872877251412923. PMID: 41530979.

Emerging evidence suggests that various microbes and mites may play a significant role in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease (AD), Lewy body dementia (LBD), and Parkinson's disease (PD). The association between microbial exposure and these conditions raises the possibility that mites, as vectors or direct agents, could contribute to disease onset and progression. PD, with 15% or less of cases linked to genetics, highlights the importance of environmental factors in the remaining sporadic cases. Mites, known to harbor prions, suggest a potential mechanism for horizontal transmission. Mites can inject neurotoxins that may disrupt neurological systems, potentially leading to movement disorders, memory loss, and cognitive decline. Conditions like seborrheic dermatitis and rosacea, linked to mites such as Demodex, are highly prevalent in patients with PD and AD, and mite-induced inflammation may exacerbate disease symptoms. Mite infestations can cause systemic illness, including respiratory, gastrointestinal, and neurological disturbances. Due to their microscopic size, they are often undetected and potentially can swap DNA with humans. This article summarizes observations linking mite exposure to neurodegenerative diseases. In one family, a member was diagnosed with LBD following chronic skin issues and mite exposure, while another developed symptoms associated with PD. Mites may contribute through prion transmission, neurotoxin injection, or by triggering inflammation. A nationwide study found that scabies patients treated with lindane, a neurotoxic pesticide, had a significantly reduced PD risk, suggesting a protective effect. These findings underscore the urgent need for further research into mites and environmental triggers.

From skin to brain: key genetic mediators associating cutaneous inflammation and neurodegenerative diseases.

Grech VS, Lotsaris K, Kefala V, Rallis E. Genes (Basel). 2025 Dec 8;16(12):1463. DOI: 10.3390/genes16121463. PMID: 41465136; PMCID: PMC12733139.

Chronic inflammatory skin diseases and neurodegenerative disorders share overlapping genetic, immunologic, and metabolic pathways that may predispose individuals to cognitive decline. This review synthesizes current human genomic, transcriptomic, and bioinformatic evidence linking psoriasis, rosacea, atopic dermatitis, and bullous pemphigoid with Alzheimer's and Parkinson's disease. Literature from PubMed, IEEE Xplore, and Google Scholar was examined, prioritizing studies integrating genomic, transcriptomic, and proteomic analyses. Among inflammatory dermatoses, psoriasis exhibits the strongest overlap with dementia genetics, with shared susceptibility loci including APOE, IL12B, and HLA-DRB5, and transcriptional regulators such as ZNF384 that converge on IL-17/TNF signaling. Rare-variant and pleiotropy analyses further implicate SETD1A and BC070367 in psoriasis-Parkinson's comorbidity. Rosacea demonstrates upregulation of neurodegeneration-related proteins SNCA, GSK3B, and HSPA8, together with shared regulatory hubs (PPARG, STAT4, RORA) driving NF-κB/IL-17/TNF-dependent inflammation. In atopic dermatitis, rare FLG variants interacting with BACE1 suggest a mechanistic bridge between barrier dysfunction and amyloidogenic processing. Bullous pemphigoid reveals an HLA-DQB1*03:01-mediated immunogenetic link hypothesis and cross-reactive autoantibodies targeting BP180 (collagen XVII) and BP230, highlighting an autoimmune route of neurocutaneous interaction. Other inflammatory and neurodegenerative diseases with currently weak or limited genetic evidence are also discussed, as they may represent emerging biological pathways or potential therapeutic targets within the skin-brain connection in the future. The aim of this work is to help clarify these genetic links and to advocate for the routine cognitive assessment of affected patients, enabling early detection, improved long-term quality of life, and the potential for timely therapeutic intervention.

Comprehensive facial skin rejuvenation with long-term regular intense pulsed light therapy: a real-world study.

Fan B, Yu R. J Cosmet Dermatol. 2026 Feb;25(2):e70691. DOI: 10.1111/jocd.70691. PMID: 41582594; PMCID: PMC12833585.

Background: Intense pulsed light (IPL) therapy is widely used for facial rejuvenation, targeting vascular, pigmentary, and textural changes. However, comprehensive, real-world evidence evaluating long-term, regular IPL treatment across multiple dimensions of skin improvement remains limited. Objectives: This study aimed to assess the efficacy and safety of long-term, regular IPL therapy in improving facial erythema, pigmentation, and wrinkles, and to identify predictors of favorable response. Methods: This retrospective real-world study included 236 patients who underwent six or more IPL sessions between 2020 and 2025. Patients were categorized as acne, rosacea, or cosmetic subjects. VISIA imaging quantified erythema, pigmentation, and wrinkle indices, while the Global Aesthetic Improvement Scale (GAIS) was used to assess aesthetic outcomes. Logistic regression identified predictors of good response. Results: Significant improvements were observed in erythema, pigmentation, and wrinkle indices after treatment (all p < 0.05). Regular treatment intervals and total number of sessions were independently associated with better outcomes (OR = 13.62 and 3.80, respectively, both p < 0.05). Patients with Fitzpatrick Type IV skin showed lower response rates (OR = 0.12, p = 0.001). VISIA analyses demonstrated quantifiable reductions in erythema and pigmentation areas, while wrinkles showed notable textural improvement. No severe adverse events occurred. Conclusions: Long-term, regular IPL therapy effectively improves facial erythema, pigmentation, and wrinkles, confirming its value as a comprehensive rejuvenation strategy. Regular treatment intervals optimize cumulative effects, while objective imaging enhances precision in outcome evaluation. These findings support IPL as a safe, evidence-based, and multidimensional approach to long-term facial rejuvenation.

Assessment of the degree of erythema reduction in rosacea after polychromatic light treatments.

Deda A, Lipka-Trawińska A, Wcisło-Dziadecka D, et al. J Clin Med. 2025 Dec 31;15(1):302. DOI: 10.3390/jcm15010302. PMID: 41517551; PMCID: PMC12786888.

Background: Rosacea is a chronic facial skin disease in which persistent erythema is a significant clinical problem, often resistant to standard therapies. Intensive pulsating light (IPL) has become a recognised and effective method of treating erythema and telangiectasia. The latest recommendations emphasise the advantage of combining subjective clinical assessments with objective imaging analyses in monitoring therapy effects. Methods: A total of 20 patients with rosacea qualified for this study. They were subjected to three polychromatic light procedures (Lumecca, Inmode; wavelength of 515-1200 nm) at 21-day intervals. The skin condition was documented photographically, and the degree of erythema was assessed on the basis of the Clinician Erythema Assessment (CEA) scale and objective analysis of the skin texture, using the parameters of contrast and homogeneity of the grey level co-occurrence matrix (GLCM). Results: A series of three polychromatic light treatments yielded a significant clinical improvement in all patients. The mean CEA value decreased by 61.11%, whereas the GLCM contrast in all the analysed facial areas dropped by about 17%, and homogeneity increased by 4-5%. The effects persisted for at least three months after the treatments. A high correlation of CEA scale results with GLCM parameters (R = 0.81-0.94 for contrast; R = -0.77 to -0.83 for homogeneity) was observed. Conclusions: Three polychromatic light treatments proved to be a very effective method of reducing erythema in rosacea, confirmed by both clinical evaluation and objective imaging analysis. The effects of therapy were durable and clear. Integration of the subjective method (CEA) with GLCM analysis can be a path for future research and clinical practice in the assessment of erythematous skin lesions.

Rosacea prevalence, severity, and phenotype by race, ethnicity, and gender: a cross-sectional study of a diverse patient cohort within a primary care population.

Gomez-Lara AR, Zakaria A, Sanchez-Anguiano ME, Amerson EH. JAAD Int. 2025 Nov 27;24:338-341. DOI: 10.1016/j.jdin.2025.11.016. PMID: 41561198; PMCID: PMC12814669.

To the Editor: Rosacea presents with several distinct clinical phenotypes, as described in the updated 2019 Global ROSacea Consensus Panel criteria. Rosacea prevalence and rosacea phenotype prevalence have primarily been studied among White European populations and vary by region and diagnostic method. A systematic review and meta-analysis estimated subtype prevalence among rosacea patients as 72% to 80% erythematotelangiectatic and 18% to 28% papulopustular, with higher prevalence among women compared to men. Given limited data describing rosacea prevalence, severity, and phenotypes among US racial/ethnic minorities, we analyzed these characteristics among a cohort of patients within a large, racially/ethnically diverse primary care population.

Systemic inflammatory and oxidative-metabolic alterations in rosacea: a cross-sectional case-control study.

Esen M, Demirbaş A, Diremsizoglu E, Canpolat Erkan RE. Diagnostics (Basel). 2026 Jan 12;16(2):246. DOI: 10.3390/diagnostics16020246. PMID: 41594223.

Background/Objectives: Rosacea increasingly appears to involve systemic immune and metabolic disturbances rather than isolated cutaneous inflammation. To evaluate inflammatory, platelet, and oxidative-metabolic biomarkers in rosacea and explore their interrelations. Methods: 90 patients with rosacea and 90 healthy controls were evaluated for hematologic inflammatory indices-neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), pan-immune-inflammation value (PIV), mean platelet volume (MPV), and C-reactive protein (CRP)-along with oxidative-metabolic regulators including sirtuin 1 (SIRT1), sirtuin 3 (SIRT3), visfatin, and irisin. Logistic regression and receiver operating characteristic (ROC) analyses were used to identify independent predictors of rosacea, while inter-marker associations were evaluated using Spearman's rank correlation. Results: Rosacea patients showed higher NLR, PLR, SII, PIV, MPV, CRP, and LDL cholesterol (p < 0.05) and lower SIRT1, SIRT3, visfatin, and irisin (p < 0.01). MPV independently predicted rosacea (OR = 7.24; AUC = 0.827), whereas SIRT1 inversely correlated with disease risk. SIRT1, SIRT3, and visfatin showed inverse correlations with HbA1c and waist-to-height ratio, while fasting glucose and HOMA-IR remained within normal ranges. Conclusions: Rosacea exhibits dual systemic activation, an inflammatory-platelet and an oxidative-metabolic axis bridging immune dysregulation, mitochondrial stress, and vascular dysfunction. Recognition of these pathways highlights the potential of redox-targeted and metabolic interventions beyond symptomatic treatment.

A ROS-responsive hydrogel microneedle system co-delivering tofacitinib and azelaic acid for enhanced targeted therapy of rosacea.

Yu Y, Ding X, Fan Y, et al. J Biomed Mater Res A. 2026 Feb;114(2):e70035. DOI: 10.1002/jbma.70035. PMID: 41586451.

Rosacea is a chronic inflammatory skin condition primarily affecting the face, characterized by symptoms such as persistent redness, visible blood vessels, papules, and pustules. Current treatments, including topical agents and systemic antibiotics, are often limited by poor skin penetration, local irritation, or the risk of systemic adverse effects and antibiotic resistance. This study designed, fabricated, and evaluated a novel ROS-responsive hydrogel microneedle (MN) system for the co-delivery of tofacitinib (a JAK inhibitor) and azelaic acid (A ZA) to treat rosacea. The hypothesis was that this Tofa/AZA@HPA-MN platform would enable triggered drug release in the high-ROS environment of inflamed skin, enhancing therapeutic efficacy and safety compared to conventional topical delivery. Topical tofacitinib and AZA were found to ameliorate LL37-induced murine rosacea-like inflammation, partly via JAK/STAT inhibition. A ROS-responsive hydrogel (HPA) was synthesized and fabricated into robust MNs, demonstrating effective skin penetration and retention. In vitro, these MNs displayed accelerated drug release under oxidative conditions and protected keratinocytes from H2O2-induced stress. In vivo, the Tofa/AZA@HPA-MNs proved superior to conventional topical Tofa + AZA and empty MNs, significantly reducing inflammation, tissue ROS levels, and JAK/STAT activation in a rosacea model. Crucially, safety assessments revealed no significant systemic toxicity, addressing the major translational concern regarding the systemic risks of JAK inhibitors. The developed system offers a promising, safe, and more effective targeted therapeutic strategy for rosacea by enabling triggered drug release directly within the inflamed skin.

Increased expression of Angiopoietin 2 and Tie2 in rosacea.

Kaya A, Saurat JH, Satta N, Kaya G. Dermatopathology (Basel). 2025 Dec 25;13(1):2. DOI: 10.3390/dermatopathology13010002. PMID: 41562711; PMCID: PMC12821430.

In this study we evaluated the expression of Angiopoietin 1, Angiopoietin 2, and Tie2 by immunohistochemistry in the skin of 10 patients with erythemato telangiectatic and papulopustular rosacea. Significantly increased expression of Tie2 and Angiopoietin 2 in the endothelial cells of the dermal vessels in rosacea skin vs. non-lesional skin (100% and 33.3% for Tie2, and 100% and 50% for Angiopoietin 2) was observed. There was no difference in the expression of Angiopoietin 1 and phosphorylated Tie2 (pTie2) between the lesional skin of rosacea and non-lesional skin.

From signal to strategy: a disproportionality analysis of dupilumab-associated rosacea in FAERS with a summary of reported clinical cases.

Li S, Lin J, Yang X, et al. J Dermatolog Treat. 2026 Dec;37(1):2605426. DOI: 10.1080/09546634.2025.2605426. Epub 2026 Jan 5. PMID: 41486954.

Purpose: Emerging evidence suggests rosacea as a recognizable adverse event during dupilumab therapy. This study aimed to investigate the potential association between dupilumab and rosacea using pharmacovigilance data and to characterize the clinical features of dupilumab-associated rosacea (DAR) through a review of reported cases. Materials and methods: We utilized the FDA Adverse Event Reporting System (FAERS) database (2017-2024) to identify disproportionality signals using four methods: Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Information Component (IC), and Empirical Bayesian Geometric Mean (EBGM). To contextualize these findings, we performed a focused narrative review of 8 publications comprising 10 DAR cases with extractable individual data. Results: A significant disproportionality signal was identified across all four methods (ROR 3.873; PRR 3.872; IC 1.865 with IC025 1.653; EBGM 3.642), with reports predominantly in adults and females. In the case review, a consistent phenotype emerged: papulopustules on persistent centrofacial erythema with frequent burning; facial predominance with occasional extension to neck, scalp, or upper trunk; frequent Demodex detection by scraping, KOH, or in vivo imaging; and occasional granulomatous histology. Onset ranged from approximately 2 weeks to 21 months, including one post-discontinuation case. Most patients improved with rosacea-directed therapy (topical ivermectin or metronidazole; anti-inflammatory-dose doxycycline). However, dechallenge or rechallenge patterns and the need for dose-interval extension, temporary interruption, or switching biologic (e.g., lebrikizumab, upadacitinib) in a subset support a drug-related pattern at the reporting level. Conclusions: DAR represents a distinct clinical entity from dupilumab-associated head and neck dermatitis, which is eczematous and typically responds to antifungals or calcineurin inhibitors. While disproportionality signals indicate association rather than incidence or causality and are subject to reporting bias, clinicians should be aware of this potential adverse event to ensure appropriate management.

A novel rat model for human meibomian gland dysfunction and ocular rosacea.

Zhu L, Rodrigues-Braz D, Gélizé E, et al. Invest Ophthalmol Vis Sci. 2026 Jan 5;67(1):14. DOI: 10.1167/iovs.67.1.14. PMID: 41533908; PMCID: PMC12798751.

Purpose: Ocular rosacea (OR) is a chronic inflammatory and vision-threatening disease of the ocular surface often associated with Meibomian gland dysfunction (MGD). Despite its clinical impact, OR remains underdiagnosed and incurable. The pathogenesis of OR and MGD is poorly understood, partly due to a lack of reliable models. This study aimed to develop a rat model of MGD and OR, and validate its relevance by comparing with the human pathology. Methods: Rat upper eyelids were exposed to UVB (300 mJ/cm2/day) for 5 days. Clinical signs, Meibomian gland (MG) morphology, and function were assessed and compared with human OR samples. Transcriptomics and lipidomics were performed to investigate UVB-induced changes. Results: UVB caused acute damage to eyelid skin and MGs with increased oxidative stress, mitochondrial dysfunction, apoptosis, inflammation, and elevated lipid production. Whereas inflammation and lipid hyperproduction decreased during the 2-week healing process, MG duct hyperkeratinization and meibocyte stem cell depletion persisted, leading to MGD and corneal epithelial defects. Progressive fibrosis in rat MGs was similar to that observed in human patients with OR, suggesting chronic and irreversible damage to MGs. Transcriptomic analysis showed shared gene regulation patterns between UVB-induced rat MGs and human rosacea and MGD. Lipidomic analysis revealed UVB-induced changes in MG lipid composition. Conclusions: This model is a valuable tool for studying the pathophysiology of MGD in OR and evaluating new treatments. The transcriptomic and lipidomic similarities between rat model and human disease provide insights into shared molecular pathways and lipid composition, offering potential biomarkers for diagnosis and therapeutic targets.

Case Reports

Successful treatment of refractory dermatomyositis with deucravacitinib (Sotyktu): a case report.

Lapa T, Breslavets M. Case Rep Dermatol. 2025 Aug 29;17(1):444-449. DOI: 10.1159/000548207. PMID: 41064318; PMCID: PMC12503779.

Introduction: Clinically amyopathic dermatomyositis (CADM) is a subtype of dermatomyositis (DM) characterized by cutaneous findings without clinically apparent muscle involvement. While immunosuppressive therapies such as methotrexate, mycophenolate mofetil, and hydroxychloroquine are commonly used, treatment-resistant cases remain a challenge. We present a case of refractory CADM successfully treated with deucravacitinib, a selective TYK2 inhibitor. Case presentation: A 50-year-old woman with a 3-year history of CADM presented with persistent facial erythema, heliotrope rash, violaceous erythema on sun-exposed areas, and Gottron's sign. Despite multiple systemic treatments, including methotrexate, mycophenolate mofetil, hydroxychloroquine, and topical and oral roflumilast, she continued to experience skin involvement and associated pain. Deucravacitinib 6 mg daily was initiated, leading to near-complete resolution of cutaneous lesions and complete resolution of pain within 10 weeks. At 6 months, her response remained stable, and she continues treatment with ongoing monitoring. Conclusion: This case highlights deucravacitinib as a potential treatment option for refractory CADM. By selectively inhibiting TYK2, it targets key inflammatory pathways involved in DM pathogenesis while minimizing off-target effects. Further studies are needed to evaluate its long-term safety and efficacy in this patient population.

Multimodal management of morbihan disease: isotretinoin, intralesional triamcinolone, and ketotifen in a recalcitrant case.

Moreno BA, Rodriguez-Puerto J, Haushalter K. Cureus. 2025 Nov 20;17(11):e97314. DOI: 10.7759/cureus.97314. PMID: 41426892; PMCID: PMC12717782.

Morbihan disease, also known as rosacea-associated solid facial edema, is a rare and chronic condition that presents with persistent facial swelling and often proves difficult to treat. We describe the case of a 57-year-old man with a four-year history of right-sided facial edema who was diagnosed with Morbihan disease after extensive prior evaluations. Intralesional triamcinolone injections at a tertiary center produced his best response, and combination therapy with isotretinoin was recommended. At our clinic, isotretinoin was initiated at 20 mg daily and titrated over several months, with doses adjusted between 10 and 40 mg based on efficacy and tolerability. A reduction to 10 mg coincided with worsening edema, while escalation improved symptoms. Adjunctive therapies included topical roflumilast, oral ketotifen, and repeat intralesional triamcinolone. Serial laboratory monitoring revealed persistent hyperlipidemia, though liver and renal function remained normal, necessitating primary care referral for lipid management. The patient reported partial improvement, most notably with higher isotretinoin dosing and intralesional corticosteroid injections, though intermittent flares persisted. This case highlights the challenges of treating Morbihan disease, emphasizing the role of individualized isotretinoin dosing, intralesional triamcinolone as a useful adjunct, and the importance of close safety monitoring and patient-centered decision-making in managing this rare condition.

News

National Rosacea Society Awards Grant for Rosacea Research

Rosacea.org

The National Rosacea Society has awarded funding for one new study as part of its research grants program to increase scientific knowledge about this once-poorly understood disorder. The program is now in its 26th year.

My Face Gets Flushed and Red. Why Is It Worsening as I Age?

The New York Times

Q: My rosacea flare-ups have gotten more intense in my 40s. Why is that, and what can I do about it?

If you have rosacea, you might notice that by the time you reach your 40s or 50s, your symptoms have gotten worse, said Dr. Julie C. Harper, a dermatologist in Birmingham, Ala.

Dry, Gritty Eyes After 50? Doctors Say Ocular Rosacea Could Be the Hidden Cause

Woman’s World

If your eyes feel gritty, dry or irritated—especially if you’re over 50—you might assume it’s just aging or allergies. But there’s another culprit that often goes undiagnosed: ocular rosacea, an inflammatory eye condition closely linked to the hormonal shifts of menopause.

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