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

Current perspectives on the human skin microbiome: functional insights and strategies for therapeutic modulation.

Suri H, Suri H, Nagda N, et al. Biomed Pharmacother. 2025 Oct 30;193:118655. DOI: 10.1016/j.biopha.2025.118655. Epub ahead of print. PMID: 41172954.

Human skin is inhabited by commensal microbiota comprising bacteria, fungi, viruses, and Demodex mites. The skin microbiome is associated with several vital functions for the host, such as maintaining barrier integrity, modulating lipid homeostasis, eliminating pathogens, and stimulating the immune reactions. However, alterations in the composition of the skin microbiome are often found to be linked with inflammatory dermatological conditions like atopic dermatitis, psoriasis, acne vulgaris, rosacea, and wound-associated infections. These conditions can be diagnosed using culture-dependent and advanced culture-independent analyses, including multi-omics platforms and high-throughput sequencing technologies. Developments in microbiome research and biotechnology have catalysed initiatives to modify the skin microbiota as a therapeutic intervention. Current strategies encompass precision medicine utilising biomarkers, transplantation of complete microbial consortia, application of specific commensal microbes, bacteriophage therapy, use of pre- and probiotic metabolites, as well as sanitizers and antibiotics. This study consolidates existing knowledge regarding the composition and functional roles of the skin microbiome, investigates dysbiosis in skin pathologies, and examines potential microbiome-targeted therapeutic interventions. The study intends to address the challenges and future directions related to the clinical implementation of microbiome-targeted approaches, encompassing the regulatory aspects necessary to guarantee the efficacy and safety of innovative diagnostic and therapeutic applications.

Hormonal versus copper intrauterine devices: a retrospective analysis of association with androgen-related dermatologic disorders using the TriNetX database.

Lampert S, Sandhu A, Ilyas EN. J Am Acad Dermatol. 2025 Oct 27:S0190-9622(25)03086-5. DOI: 10.1016/j.jaad.2025.10.088. Epub ahead of print. PMID: 41161598.

Hormonal intrauterine devices (hIUDs) are levonorgestrel (synthetic progesterone) based implanted contraceptives with minimal systemic absorption. Recent studies, however, have noted a potential increased risk of rosacea and adverse androgenic dermatologic outcomes such as acne, hair loss, and hirsutism. While smaller scale reviews have studied these outcomes with variable results, more comprehensive analyses using larger datasets over longer durations have been limited. This study investigates rosacea and specific androgenic dermatologic outcomes over time in relation to hIUDs and copper IUDs.

Microbe-host interaction in rosacea and its modulation through topical ivermectin.

Olah P, Reuvers N, Radai Z, et al. J Invest Dermatol. 2025 Oct;145(10):2576-2587.e8. DOI: 10.1016/j.jid.2025.03.031. Epub 2025 Apr 11. PMID: 40220854.

Rosacea is characterized by inflammatory lesions, often accompanied by an increased density of the common skin mite Demodex folliculorum. Although rosacea shows a high prevalence and significantly affects the QOL of patients, the underlying mechanisms, especially the role of cutaneous dysbiosis, are largely unknown. Hence, we aimed to systematically characterize disease severity of patients with rosacea in the context of mite density, the cutaneous microbiome, and the host's transcriptome before and after 30 days of topical 1% ivermectin cream treatment. At day 30, a marked decrease in mite density was observed in 87.5% of patients. At day 0, distinct microbial community changes included the decrease in Cutibacterium acnes abundance, whereas Staphylococcus epidermidis colonization increased compared with that in healthy volunteers. Interestingly, the insect symbiont Snodgrassella alvi was recovered from a highly Demodex-colonized patient and eradicated by treatment on day 30. Although topical ivermectin did not affect bacterial dysbiosis, the host's transcriptome significantly normalized, and an "ivermectin transcriptomic signature" was defined. Findings of this study support that rosacea lesions are associated with dysbiosis. However, improvement of clinical signs during topical ivermectin is not associated with normalization of the bacterial microbiome but rather a decrease of transcriptomic dysregulation and mite density.

Corneal confocal microscopy identifies neurodegeneration in relation to disease severity and neuropathic symptoms in rosacea.

Petropoulos IN, Buddenkotte J, Joy F, et al. J Invest Dermatol. 2025 Oct;145(10):2609-2612. DOI: 10.1016/j.jid.2025.03.047. Epub 2025 May 14. PMID: 40378948.

Corneal confocal microscopy (CCM) is a noninvasive ophthalmic imaging technique that has been used to identify neurodegeneration in diabetic and other peripheral and central neurodegenerative diseases and to identify corneal conjuctivalization and meibomian and skin gland alterations in patients with rosacea. We now seek to demonstrate the utility of CCM to assess neurodegeneration in relation to disease onset and progression, subtypes, and treatment efficacy in patients with rosacea.

Rosacea as a neurocutaneous disorder: in vivo corneal confocal microscopy reveals neurologic alterations.

Liao K, Buhl T. J Invest Dermatol. 2025 Oct;145(10):2382-2385. DOI: 10.1016/j.jid.2025.04.003. Epub 2025 May 27. PMID: 40423603.

Although rosacea has traditionally been defined by its visible cutaneous manifestations such as erythema, telangiectasia, papules, and pustules, increasing evidence suggests that its pathophysiology involves deeper neuroimmune and inflammatory mechanisms. Patients with erythematotelangiectatic and papulopustular subtypes frequently report neuropathic symptoms such as burning, stinging, and hypersensitivity, which may suggest small-fiber neuropathy and are indicative of underlying neural involvement. This knowledge gap is especially evident in ocular rosacea, where diagnostic ambiguity persists owing to the absence of standardized criteria; neither dermatologists nor ophthalmologists are typically able to diagnose it independently. Therefore, ocular rosacea is frequently unrecognized or misdiagnosed, especially in the absence of concurrent cutaneous manifestations. The recent study by Petropoulos et al is the first to apply corneal confocal microscopy (CCM) to assess corneal nerve structure in patients with rosacea, which demonstrates a significant reduction in corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), and corneal nerve fiber length (CNFL), compared with that in healthy controls. These neuroanatomic changes were particularly pronounced in individuals reporting neuropathic symptoms such as facial burning, suggesting that CCM may serve as a potential diagnostic tool of neural involvement in rosacea. Moreover, this approach may provide a novel framework for distinguishing disease subtypes, quantifying disease severity, and objectively monitoring treatment response in a reproducible manner.

Dermoscopy of rosacea: A cross-sectional study comparing dark and light phototypes.

Khachani K, Asermouh M, Moumna R, et al. JAAD Int. 2025 Aug 28;23:80-83. DOI: 10.1016/j.jdin.2025.05.022. PMID: 41209649; PMCID: PMC12595383.

To the Editor: Rosacea is a chronic inflammatory skin condition that is well-documented in light phototypes and less frequently reported in individuals with darker skin. Dermoscopy can be useful for the detection of the early features of rosacea that may not be visible clinically in dark phototypes. Our study aimed to describe dermoscopic features of rosacea in dark phototypes and compared them with those in light phototypes.

Rosacea and seborrheic dermatitis: a retrospective cohort study.

Koch RS, Nguyen KT, Karnati AA, et al. Proc (Bayl Univ Med Cent). 2025 Jul 30;38(6):996-997. DOI: 10.1080/08998280.2025.2537558. PMID: 41210570; PMCID: PMC12591579.

Rosacea and seborrheic dermatitis are both chronic inflammatory skin conditions with facial distributions. Using the TriNetX database, we investigated the concomitance of rosacea and seborrheic dermatitis. After propensity score matching, rosacea patients had an increased risk of seborrheic dermatitis (odds ratio 6.456; 95% confidence interval, 6.155-6.772; P <0.0001). This significant correlation emphasizes the importance of clinicians remaining observant for signs of both conditions when diagnosing and managing patients with either disease.

LAPTM5 exacerbates STING-mediated inflammation induced by LL-37 through stabilizing STING in rosacea.

Huang W, He H, Wu H, et al. Commun Biol. 2025 Oct 14;8(1):1470. DOI: 10.1038/s42003-025-08861-8. PMID: 41087666; PMCID: PMC12521404.

Rosacea is a chronic inflammatory skin disorder linked to the antimicrobial peptide LL-37 and immune cells. STING, a key DNA-sensing adaptor, initiates innate immune responses, with excessive activation contributing to inflammation. This study investigates LAPTM5, a STING-interacting protein, and its role in rosacea. We observe elevated nuclear DNA fragmentation within the dermal lesions of rosacea patients and LL-37-induced rosacea-like mice. LAPTM5 and STING levels are upregulated in macrophages within rosacea lesions and LL-37-induced models, along with STING hyperactivation. LAPTM5 knockdown in macrophages reduces STING protein levels, signaling, and inflammatory responses under DMXAA and HT-DNA stimulation. LAPTM5 associates with STING and represses its K48- and K63-linked polyubiquitination, preventing proteasomal and lysosomal degradation, thereby maintaining STING stability at homeostasis and after activation. Both STING antagonist H-151 and LAPTM5 knockdown alleviate LL-37-induced rosacea-like phenotypes. These findings highlight LAPTM5 as a STING stabilizer, aggravating STING-driven inflammation in rosacea, offering insights for potential treatments.

Healthy plant-based dietary pattern is associated with a lower risk of rosacea.

Zhang Y, Yang F, Zheng WR, et al. J Eur Acad Dermatol Venereol. 2025 Nov 18. DOI: 10.1111/jdv.70163. Epub ahead of print. PMID: 41255052.

Background: Several plant-based dietary foods are associated with the rosacea risk, but the associations between plant-based dietary patterns and the risk of rosacea remain unclear. Objectives: We aimed to examine the associations of plant-based dietary patterns, represented by three plant-based diet indices (PDIs), with the risk of rosacea. Methods: This prospective cohort study included 198,557 participants free of rosacea at baseline from the UK Biobank. Three PDIs (the overall plant-based diet index, PDI; the healthful plant-based diet index, hPDI; and the unhealthful plant-based diet index, uPDI) were calculated from 24-h dietary recalls based on 17 food groups. The primary outcome was the risk of rosacea. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Results: During a median follow-up of 13.46 years, 1075 new-onset rosacea cases were recorded. Each 10-point increase in the PDI and hPDI was associated with a 16% (95% CI: 0.76, 0.94) and 9% (95% CI: 0.82, 1.00) decrease in the risk of rosacea, respectively, whereas each 10-point increase in the uPDI was associated with a 12% (95% CI: 1.02, 1.24) increase in the risk. Compared with participants in the lowest PDI quintile, those in the highest PDI quintile had a lower risk of rosacea, with a HR of 0.78 (95% CI: 0.63, 0.95; p for trend = 0.004). In contrast, compared with participants in the lowest uPDI quintile, participants in the highest uPDI quintile had a higher risk of rosacea, with a HR of 1.23 (95% CI: 1.02, 1.48; p for trend = 0.046). Conclusions: A higher PDI or hPDI decreased the risk of rosacea, whereas a higher uPDI increased the rosacea risk. These findings suggest that adhering to an overall or a healthful plant-based pattern while avoiding an unhealthful plant-based pattern should be recommended as preventive strategies for rosacea.

Bidirectional associations between seborrheic dermatitis and epithelial barrier diseases: a retrospective cohort study.

Meng S, Berna R, Takeshita J, et al. Allergy. 2025 Oct 27. Epub ahead of print. DOI: 10.1111/all.70112. PMID: 41144761.

Background: Seborrheic dermatitis (SD) is a common skin disease characterized by epithelial barrier breakdown. The epithelial barrier theory (EBT) implicates epithelial barrier disruption in the development of epithelial barrier diseases (EBDs). We hypothesized that SD is associated with an increased risk of EBDs and investigated the bidirectional association between SD and EBDs. Methods: Retrospective cohort study of 5,083,689 patients using a large US administrative claims database from January 1, 2016, to June 30, 2022. The mean (standard deviation) follow-up was 3.25 (1.75) years with a total follow-up of over 16 million person-years. The outcomes were a diagnosis of (i) SD after an EBD and (ii) EBD after SD, analyzed using a multivariable Cox proportional hazards model (hazard ratio [95% confidence interval]). Results: The risk of SD was increased after EBD diagnosis for multiple diseases, including atopic dermatitis [2.46 (2.40, 2.53)], alopecia areata [3.47 (3.24, 3.71)], contact dermatitis [1.92 (1.88, 1.96)], psoriasis [2.62 (2.54, 2.69)], rosacea [2.84 (2.78, 2.90)], hidradenitis suppurativa [1.79 (1.63, 1.97)], rhinosinusitis [1.34 (1.32, 1.35)], food allergy [1.47 (1.42, 1.54)], celiac disease [1.55 (1.43, 1.68)], ocular allergy [1.55 (1.49, 1.61)], and dry eye [1.54 (1.52, 1.56)]. The risk of EBD after SD diagnosis followed similar trends, with the largest effect estimates being psoriasis [3.52 (3.42, 3.61)], rosacea [2.85 (2.79, 2.92)], and alopecia areata [2.81 (2.61, 3.03)]. Conclusions: Our results support the EBT as a shared driver of EBD pathogenesis at not only local (e.g., skin) barriers but also at non-local sites, including the respiratory, gastrointestinal, and ocular epithelial barriers.

Case Reports

Cutaneous and ocular rosacea associated with elexacaftor, tezacaftor and ivacaftor, a treatment for cystic fibrosis: a case report.

Piednoir A, Troussier F, Descamps M, et al. J Pediatr Clin Pract. 2025 Oct 10;18:200187. doi: 10.1016/j.jpedcp.2025.200187. PMID: 41209022; PMCID: PMC12593642.

A 6-year-old girl with cystic fibrosis developed ocular and cutaneous rosacea after the initiation of elexacaftor-tezacaftor-ivacaftor therapy. Her symptoms improved upon discontinuation and recurred with reintroduction, suggesting a drug-induced reaction. This case suggests a potential, previously unreported association between elexacaftor-tezacaftor-ivacaftor and rosacea, possibly mediated by microbiome alterations and inflammation.

Granulomatous rosacea treated with tapinarof.

Brady M, Wang V, Kartono F, Sikorski L. JAAD Case Rep. 2025 Jul 11;64:1-2. DOI: 10.1016/j.jdcr.2025.06.038. PMID: 40918550; PMCID: PMC12410136.

Granulomatous rosacea (GR) is a rare variant of rosacea marked by granulomatous inflammation. Clinically, it manifests as persistent erythema, papules, and yellowish brown hard nodules, most commonly affecting the forehead. It can also affect the periocular and perioral areas, and is typically seen in middle-aged women. Histologically, GR is defined by granulomatous infiltrates consisting primarily of lymphocytes, histiocytes, and multinucleated giant cells. The exact pathogenesis of GR remains unclear, though it is believed to involve immune dysregulation and antigenic triggers leading to granuloma formation.2 Treatment of GR is difficult and often involves a combination of topical and systemic therapies. Tetracyclines are often used for their anti-inflammatory properties; however, there is no standard treatment. Tapinarof is a topical, nonsteroidal, aryl hydrocarbon receptor agonist typically used to treat plaque psoriasis. It has been approved by the US Food and Drug Administration for the treatment of plaque psoriasis in adults and is under investigation for atopic dermatitis. We report a case of a patient with GR refractory to initial treatments that later resolved with tapinarof.

News

Ocular Rosacea Underappreciated in Dermatology and Beyond

Medscape

Although ocular disease commonly occurs in people with rosacea, ocular rosacea remains underrecognized by dermatologists and even eye specialists, according to experts. Fortunately, an ophthalmologist told Medscape Medical News that ocular rosacea responds to largely the same treatments as other rosacea types, and research continues to produce therapeutic advances for ocular symptoms.

Do Fungi Play a Role in Rosacea?

Rosacea.org

It is well established that differences in the microbiome — the ecological community of microorganisms that live within and on the human body — plays a role in the development of rosacea and affect the severity of signs and symptoms. Research shows that rosacea patients often suffer from an overgrowth of Demodex mites, a natural inhabitant of the skin of nearly every human, and mounting evidence points to an imbalance of bacteria in both the skin and gut microbiome as influencing the development and severity of rosacea signs and symptoms. However, a new study has focused on an overlooked portion of the microbiome that may also be involved in rosacea’s development: yeasts and other fungi.

Tips for Improving Rosacea Recognition in Patients With Skin of Color at Elevate-Derm

Dermatology Times

Addressing issues in recognizing rosacea in patients with skin of color continues to be an important topic, Hilary Baldwin, MD, told attendees of the 2025 Elevate-Derm Fall Conference. Baldwin, who runs the Acne Treatment and Research Center in Brooklyn, New York, emphasized the diagnostic and treatment considerations for this patient population in her talk. “This is a specific issue, not so much because treatment is different or because lesion morphology is different, but because we simply are not recognizing the entity,” Baldwin told Dermatology Times.

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