🧬 Aging Wiki

rosacea

Properties1
aliasesacne rosacea, facial rosacea, rosacea vulgaris

21 min read

Rosacea

A chronic, relapsing, centrofacial inflammatory skin condition characterised by persistent erythema, flushing, papulopustular eruptions, telangiectasia, and in a subset of patients, ocular involvement and phymatous skin thickening. Rosacea is relevant to the aging wiki as a major cause of fixed facial redness that worsens with cumulative UV exposure and vascular aging, and whose innate-immune underpinning — cathelicidin LL-37 overproduction driven by elevated serine protease activity — intersects directly with the chronic-inflammation hallmark and with the cathelicidin biology documented on camp. Rhinophyma (the nasal form of phymatous rosacea) is covered mechanistically under ear-nose-enlargement.

ICD-10 note: L71 = Rosacea (primary code). Subtypes: L71.1 = Rhinophyma; L71.8 = Other rosacea (used for ocular manifestations); L71.9 = Rosacea, unspecified. L71.0 = Perioral dermatitis — not ocular rosacea despite common assumption; perioral dermatitis is a distinct entity. Ocular rosacea is coded under relevant ophthalmological ICD codes (e.g. H10.x conjunctivitis).

Classification — from subtypes to phenotypes

Old 4-subtype system (NRS, pre-2017)

The National Rosacea Society previously classified rosacea into four subtypes:

SubtypeNameCardinal features
1Erythematotelangiectatic (ETR)Persistent centrofacial erythema, flushing, telangiectasia
2Papulopustular (PPR)Central facial papules, pustules, ± erythema; resembles acne but comedones absent
3PhymatousSkin thickening, rhinophyma, sebaceous gland hypertrophy
4OcularBlepharitis, conjunctivitis, iritis, stye

The subtype system fell out of favour because patients frequently manifest features across categories simultaneously (e.g. erythema + papules + ocular symptoms), and treatment decisions should be phenotype-led.

Modern ROSCO phenotype-based approach (2017–present)

The Global ROSacea COnsensus (ROSCO) panel, in 2017 and updated in 2019, moved to a phenotype-based diagnostic framework 12:

Diagnostic features (presence of one is sufficient for diagnosis):

  • Fixed centrofacial erythema with or without telangiectasia
  • Phymatous changes

Major features (two or more = diagnosis in the absence of a diagnostic feature):

  • Flushing/transient erythema
  • Papules and pustules (central facial)
  • Telangiectasia (see telangiectasia — being seeded in parallel)
  • Ocular manifestations (lid margin telangiectasia, blepharitis, keratitis, conjunctivitis, anterior uveitis) 2

Minor features (supportive, not independently diagnostic):

  • Burning or stinging sensation, facial edema, periocular manifestations, dry appearance

This approach allows description of individual patient phenotypic burden, matching treatment to the dominant feature(s) rather than a rigid subtype assignment.

Pathophysiology — multi-hit model

Rosacea results from the convergence of at least four partially independent pathophysiological axes; no single axis fully explains all phenotypes.

(a) Innate immune dysregulation — the cathelicidin/KLK5 axis

The dominant mechanistic model, established by Yamasaki et al. 2007 (Nature Medicine):

  1. Elevated KLK5 (kallikrein-5) activity — stratum corneum tryptic enzyme (SCTE/KLK5) is overexpressed in rosacea-affected skin, driving excessive serine protease activity in the stratum corneum 3.
  2. Cathelicidin overprocessing — elevated KLK5 cleaves the cathelicidin precursor hCAP-18 at unusual sites, generating pro-inflammatory LL-37 peptide fragments in excess and with abnormal cleavage products not seen in healthy skin 3.
  3. Sterile inflammation — overproduced LL-37 activates TLR2 on keratinocytes and immune cells, driving NF-κB-mediated cytokine release (IL-1β, IL-8, IL-6, CXCL1) and VEGF-stimulated angiogenesis/telangiectasia. This creates the fixed erythema characteristic of ETR-dominant rosacea.
  4. TLR2 sensitization amplifies the loop — TLR2 expression is upregulated in rosacea lesional skin, making keratinocytes hyper-responsive to microbial and danger signals and further amplifying KLK5-dependent serine protease induction 4.

See camp (the CAMP/hCAP-18 protein page) which documents the cathelicidin biology in detail including its aging context; the rosacea axis is noted there as a case of pathological cathelicidin overactivation (contrast with the more common aged-skin problem of cathelicidin insufficiency).

Mechanism conservation:

DimensionStatus
Pathway characterised in humans?yes — Yamasaki 2007 directly in human biopsy tissue + mouse model
Phenotype reproduced in mouse model?yes — superficial subcutaneous injection of LL-37 or rosacea-derived cathelicidin peptides (FA-29) produces erythema, vascular dilatation, and neutrophilic infiltrate in BALB/c and C57BL/6 mice 3
Replicated independently?yes — KLK5 elevation confirmed in multiple biopsy cohorts; targeted by azelaic acid and ivermectin mechanisms 56

(b) Neurovascular dysregulation

Rosacea skin is characterised by neurovascular hyperreactivity that explains the flushing phenotype 7:

  • TRPV1 and TRPA1 channel sensitisation — thermosensitive transient receptor potential channels on cutaneous sensory neurons are sensitised in rosacea skin; common triggers (heat, spicy food, alcohol, sun) activate TRPV1/TRPA1 → neuropeptide release (substance P, CGRP, VIP) → mast cell degranulation → vasodilation → flushing.
  • Cutaneous vascular hyperreactivity — independent of neural input, rosacea-affected dermal vasculature has reduced vasoconstrictor tone; persistent dilation contributes to fixed erythema.
  • Neurogenic inflammation loop — neuropeptides from sensitised C-fibers amplify mast cell and dendritic cell activation, feeding back into the innate immune dysregulation axis above.

The neurovascular axis explains trigger-dependent flushing (major feature) more directly than the cathelicidin axis does.

(c) Demodex folliculorum density and skin microbiome

Demodex folliculorum mite density is consistently elevated in rosacea-affected skin (up to 10–18 mites/cm² vs <5/cm² in controls) 7, likely through two mechanisms:

  1. Direct microbial trigger — Demodex carries Bacillus oleronius bacteria in its gut; when Demodex dies within follicles, bacterial antigens are released, activating TLR2 on local keratinocytes and macrophages → LL-37 induction → cathelicidin axis amplification. This mechanistically links the Demodex-burden and innate-immune axes.
  2. Physical follicular obstruction — excess Demodex density may mechanically obstruct sebaceous follicles, contributing to papulopustular morphology.

A 2023 systematic review and meta-analysis of anti-Demodex strategies (Li et al., n=21 studies covering rosacea and blepharitis) found that topical ivermectin showed the largest Demodex mite-density reduction at 1–3 months among the strategies evaluated; permethrin and tea tree oil were also effective; intense pulsed light was competitive beyond 3 months 8. Ivermectin additionally suppresses cathelicidin, KLK5, and pro-inflammatory gene expression in keratinocytes — both anti-Demodex and anti-cathelicidin mechanisms contribute to its efficacy 6.

The dysbiotic skin microbiome angle — including sebum-mediated changes in malassezia and bacterial community composition — is covered in skin-microbiome-aging-shifts. As sebum declines with age, the Demodex substrate changes and the relationship between mite density and inflammatory response may shift; this has not been fully characterised in older adults. gap/no-mechanism

(d) UV and reactive oxygen contribution

Ultraviolet radiation is one of the strongest and most consistent environmental triggers of rosacea flares 9. The UV–rosacea relationship operates on two timescales:

  • Acute (minutes-to-hours) — UVA/UVB activates cathelicidin promoters in keratinocytes, directly inducing LL-37 overproduction, and triggers TRPV1/TRPA1 thermoreceptors → flushing.
  • Chronic (years-to-decades) — cumulative photodamage drives vascular ectasia (persistent telangiectasia) and progressive dysregulation of the dermal innate immune tone. UV-generated reactive oxygen species (ROS) activate matrix metalloproteinases (MMPs) that remodel the perivascular extracellular matrix, impairing vessel wall integrity and reducing the mechanical resistance against dilation. This is the primary mechanism by which aging-associated cumulative UV exposure worsens the vascular phenotype (fixed telangiectasia, diffuse erythema) of rosacea.

This UV–vascular interaction makes photoprotection (uv-protection) the single most important geroprotective measure for preventing progression of the erythematotelangiectatic phenotype.

(e) Alcohol: trigger, incidence risk, and the rhinophyma question

Acute trigger and epidemiological incidence risk. Alcohol is one of the most consistently reported rosacea triggers (alongside heat, sun, spicy food, and exercise). Mechanistically, ethanol and its metabolite acetaldehyde activate TRPV1/TRPA1 channels on cutaneous sensory neurons, release substance P and CGRP, and degranulate mast cells — producing vasodilation and the rosacea flush 7. Beyond acute triggering, prospective cohort evidence from the Nurses’ Health Study II (82,737 US women, 14-year follow-up, 4,945 incident rosacea cases) demonstrates a dose-dependent relationship between habitual alcohol intake and incident rosacea 10:

  • 1–4 g/day: HR 1.12 (95% CI 1.05–1.20) vs non-drinkers
  • ≥30 g/day: HR 1.53 (95% CI 1.26–1.84)

White wine and liquor showed the strongest beverage-specific associations (p<0.001 and p=0.0006 respectively), adjusted for sun exposure, smoking, and other confounders. A 2022 systematic review and meta-analysis of 14 studies confirms this direction and finds the association is strongest for the phymatous rosacea subtype specifically (OR 4.17; 95% CI 1.76–9.91) 11.

The rhinophyma-alcohol question: evidence in tension. The cultural link between heavy drinking and “whiskey nose” / “rum blossom” (rhinophyma) is one of the most contested associations in clinical dermatology.

  • The traditional clinical teaching holds that rhinophyma — phymatous rosacea of the nose, characterised by fibrous-stroma expansion, sebaceous gland hypertrophy, and dilated follicles — occurs in lifelong non-drinkers and has been documented in teetotallers in the literature. The histological mechanism (rosacea-driven chronic inflammation → sebaceous hyperplasia → fibrous matrix remodelling) is not specific to alcohol-related vascular injury. Augustynowicz et al. (2016, JAMA Dermatology) specifically characterised the alcohol-rhinophyma link as an entrenched cultural myth — “The Bard’s Blunder” — rooted in literary and artistic portraiture of red-nosed drinkers rather than causal pathology 12.
  • The recent epidemiological view offers nuance: Second et al. (2019, JAAD, brief report) document an association between rhinophyma and alcohol intake in a clinical cohort 13, and the Liu et al. (2022) meta-analysis finds OR 4.17 specifically for phymatous rosacea with alcohol — the strongest subtype-specific signal in the dataset 11.

Framing the discordance. The most parsimonious reconciliation is that alcohol does not cause rhinophyma de novo in individuals without rosacea (rhinophyma occurs in non-drinkers; its histological drivers are rosacea-specific), but heavy alcohol use may accelerate phymatous progression in individuals already predisposed to rosacea by amplifying trigger frequency and inflammatory burden. The epidemiological association signal likely captures this facilitation pathway rather than an independent causal mechanism. gap/contradictory-evidence for a study comparing rhinophyma incidence in heavy drinkers without rosacea vs matched non-drinkers without rosacea.

Rhinophyma is structurally permanent and requires surgical management. Regardless of aetiology, phymatous thickening — once established — does not reverse with topical/systemic therapy or with alcohol abstinence. Rhinophyma requires surgical or laser debulking: CO₂ laser resurfacing, Er:YAG ablation, dermabrasion, electrosurgery, or cold-steel excision. This permanent-structural-damage angle is analogous to the fixed telangiectasia covered throughout this page: once a structural change has occurred, removal of the functional trigger (alcohol, UV, or rosacea inflammation) does not reverse it. See ear-nose-enlargement for rhinophyma mechanism and management. See erythema for the parallel discussion of chronic-alcohol persistent facial redness.

Aging relevance

Rosacea is relevant to the aging wiki for three distinct reasons:

  1. Cumulative UV exposure amplifies the vascular phenotype. Fixed telangiectasia (the hallmark of ETR) accumulates via chronic UV-driven perivascular MMP remodelling and loss of vessel-wall tone — the same process that underlies solar elastosis and solar purpura more broadly. Photoprotection from the third decade onward is a primary prevention strategy for the vascular component. See telangiectasia for the vascular biology.

  2. The cathelicidin axis intersects with aged-skin immunity. While the cathelicidin problem in aging more broadly is insufficiency (fewer adipogenic dermal fibroblasts, vitamin D decline — see camp), rosacea skin presents the opposite: pathological LL-37 overproduction. This phenotypic polarity is mechanistically informative — it demonstrates that both too little and too much LL-37 signalling are pathological states, and that the LL-37 “set point” is finely regulated. As the dermis ages (senescent fibroblasts, reduced ECM homeostasis), the regulatory mechanisms that normally buffer LL-37 production become less reliable.

  3. Cellular senescence in the dermis amplifies rosacea severity. Senescent dermal fibroblasts and endothelial cells expressing the SASP generate IL-1β, IL-6, and VEGF locally. This amplifies vasodilation, promotes telangiectasia, and may lower the threshold for mast cell degranulation. The interaction between rosacea’s intrinsic inflammatory state and age-accumulated SASP has not been directly studied, but is mechanistically plausible and represents an important gap. cellular-senescence is therefore listed as a contributing hallmark. gap/no-mechanism

Therapeutic landscape

The modern evidence base for rosacea treatment is phenotype-led: match the therapy to the dominant clinical feature(s).

Anti-inflammatory topicals (papulopustular phenotype)

AgentMechanismEvidence
Topical metronidazole 0.75–1%Anti-inflammatory (inhibits ROS, neutrophil activation); weak anti-Demodex activityCochrane-reviewed; reduces lesion counts vs. placebo; GRADE moderate quality 14 — no wiki page yet gap/stub
[[azelaic-acidAzelaic acid]] 15% gelInhibits KLK5 and reduces cathelicidin LL-37 at the protein level; anti-inflammatory via NF-κB inhibition
Ivermectin 1% cream (topical)Kills Demodex mites (anti-parasitic); additionally inhibits cathelicidin, KLK5, and CXCL1 in keratinocytes 6; dual mechanismMeta-analysis: superior to topical metronidazole for papulopustular lesion reduction 8; well-tolerated; two phase III RCTs (PMID 29944217) — no wiki page yet gap/stub

Vasoactive topicals (erythema phenotype)

AgentMechanismEvidence
[[brimonidineBrimonidine]] 0.33% gelSelective α₂-adrenoceptor agonist; topical vasoconstriction; effect onset ~30 min, duration ~12 h
[[oxymetazolineOxymetazoline]] 1% creamα₁-adrenoceptor agonist; topical vasoconstriction; FDA-approved for persistent facial erythema of rosacea (2017)

Both vasoconstriction agents address erythema symptomatically (hours-long windows) rather than mechanistically modifying the underlying disease; they do not reduce telangiectasia.

Sub-antimicrobial oral doxycycline (papulopustular phenotype)

Oral doxycycline 40 mg modified-release (30 mg immediate-release + 10 mg delayed-release) exploits doxycycline’s anti-inflammatory properties at concentrations insufficient to exert meaningful antibiotic selection pressure 15:

  • At 40 mg/day, plasma doxycycline levels are below the minimum inhibitory concentration for most Gram-negative organisms — resistance risk is negligible vs. standard antibiotic doses.
  • Anti-inflammatory mechanisms include MMP inhibition, neutrophil migration suppression, and cytokine downregulation.
  • Two phase III RCTs (Del Rosso 2007, combined n=537: 269 doxycycline, 268 placebo) showed significantly greater reduction in papulopustular lesion count vs. placebo (p<0.001 for both studies) with sustained effect at 16 weeks 15.
  • This is not an antibiotic course — the FDA-approved indication is specifically anti-inflammatory for rosacea; prolonged use does not generate antimicrobial resistance at this dose.

Vascular laser and intense pulsed light (ETR phenotype)

Fixed telangiectasia and diffuse erythema — the components that topical and oral therapies do not address well — respond to light-based vascular treatments (see vascular-laser for the canonical device-page detail):

  • Pulsed dye laser (PDL, 585/595 nm) and potassium-titanyl-phosphate (KTP) laser (532 nm): selectively target oxyhemoglobin in superficial dermal vessels; photocoagulate telangiectasia; established evidence in multiple open-label series and small RCTs (PMID 35630068, PMID 41778357).
  • Intense pulsed light (IPL, 515–1200 nm broadband): effective for diffuse erythema and small telangiectasia via similar oxyhemoglobin selectivity; reviewed in van Zuuren 2019 (GRADE low-to-moderate certainty) 14.
  • Neither laser/IPL modality modifies the underlying cathelicidin dysregulation — recurrence is expected without continued photoprotection and trigger avoidance; sessions typically repeated every 6–12 months for maintenance.

Skin barrier support and microbiome-targeted care

  • niacinamide (topical, 2–5%): barrier-strengthening via ceramide and free fatty acid induction; reduces transepidermal water loss; referenced for rosacea use in skin-microbiome-aging-shifts. Not directly anti-cathelicidin but reduces barrier vulnerability that permits KLK5 activity.
  • Gentle cleanser + non-irritating moisturiser: foundational; reduces trigger exposures. gap/stub — no wiki intervention page for this.

Hallmark mapping

HallmarkContribution
chronic-inflammationPrimary driver; cathelicidin/KLK5 overproduction drives NF-κB-mediated sterile inflammation; TLR2 sensitisation; mast cell and dendritic cell hyperactivation; SASP cytokines from senescent dermis amplify local milieu
cellular-senescenceSenescent dermal fibroblasts and endothelial cells (SASP: IL-1β, IL-6, VEGF) lower the threshold for vascular reactivity and inflammatory amplification; increases with cumulative photodamage and age

Rosacea sits primarily in the chronic-inflammation hallmark with a secondary contribution from cellular-senescence. It is a phenotypic output of innate immune dysregulation rather than a driver hallmark. Cumulative photodamage acts as an environmental amplifier of the vascular component via oxidative stress and perivascular MMP remodeling.

Epidemiology

The RISE study (Tan et al. 2016, n=6,065 total screened: Germany n=3,052, Russia n=3,013; aged 18–65) found an overall rosacea prevalence of 12.3% [95%CI 10.2–14.4] in Germany (dermatologist-assessed) and 5.0% [95%CI 2.8–7.2] in Russia, with a female predominance (74.8% of confirmed cases) and the erythematotelangiectatic phenotype being most common (67.2% of confirmed cases) 16. Fair skin (Fitzpatrick phototypes I–II) is the strongest demographic risk factor; rosacea is significantly less prevalent in darker skin types, though it is reported across all phototypes and may be underdiagnosed in darker skin 17. Family history represents an additional risk modifier (genetic epidemiology data are limited). The peak prevalence decade varies by study (30–60 range), with no strong evidence of marked prevalence increase beyond age 65.

Clinical context and differential diagnosis

Rosacea is commonly misdiagnosed or conflated with:

  • Acne vulgaris — rosacea papulopustular phenotype lacks comedones; acne has comedones and typically starts earlier
  • Seborrhoeic dermatitis — overlapping distribution; may co-exist (see malassezia); seborrheic dermatitis features flaking/scaling absent in rosacea
  • Perioral dermatitis (ICD-10 L71.0 — distinct from rosacea despite same ICD category): periorificial papulopustules without centrofacial erythema/flushing; strongly associated with topical or inhaled corticosteroid use
  • Lupus erythematosus — malar rash can mimic ETR; distinguished by systemic features, anti-dsDNA/ANA serology
  • Contact dermatitis — history of allergen/irritant exposure; patch testing differentiates

Limitations and gaps

  1. No validated 65+ prevalence figure — the RISE study and most epidemiological studies do not specifically characterise prevalence in adults aged 65+. Whether rosacea remits, persists, or transforms in phenotype in the oldest-old is unknown. gap/needs-replication

  2. Cellular-senescence mechanism hypothesis is untested — the hypothesis that SASP from aged dermal senescent cells amplifies rosacea severity is mechanistically plausible but not directly tested in any human cohort or animal model. gap/no-mechanism

  3. Demodex density × aging interaction — whether aging alters the Demodex-rosacea relationship (through changes in sebum, immune surveillance, or follicular architecture) has not been studied. gap/needs-replication

  4. Laser/IPL evidence quality — most vascular treatment evidence comes from open-label series and small RCTs; large randomised head-to-head laser vs. IPL vs. control trials are absent. GRADE assessments in van Zuuren 2019 14 rate vascular evidence as low–moderate. gap/needs-replication

  5. Treatment response in older adults — all major RCTs for rosacea treatments (topical metronidazole, azelaic acid, ivermectin, doxycycline) enrolled predominantly 30–60-year-olds; treatment efficacy and safety in patients >65 are not separately reported. gap/long-term-unknown

  6. Missing compound pages — the microbial-targeting topicals metronidazole (antibiotic) and ivermectin (anti-Demodex) still lack dedicated wiki pages. gap/stub (The vasoconstrictors brimonidine / oxymetazoline, azelaic-acid, doxycycline, and the vascular laser/IPL device page have since been seeded.)

  7. No telangiectasia page yet — telangiectasia is listed as an implicit stub; the vascular biology cross-reference will gain substance when that page is seeded.

  8. ICD-11 subtype codes — the main code EA90 (Rosacea) is listed in frontmatter but subtype codes have not been confirmed against the WHO ICD-11 browser. gap/needs-canonical-id

Cross-references

  • camp — cathelicidin biology; note rosacea-specific overactivation vs. age-related insufficiency in normal aging skin
  • ear-nose-enlargement — rhinophyma (phymatous rosacea of nose); the aging-structural mechanism (AGE crosslinking, ptosis) overlaps; rosacea-driven sebaceous hypertrophy is a distinct additional layer
  • skin-microbiome-aging-shifts — Demodex / Malassezia / Cutibacterium community context; azelaic acid and niacinamide referenced there for rosacea
  • malassezia — fungal dysbiosis; sebum decline and rosacea share a sebaceous-niche disruption
  • telangiectasia — vascular biology underlying fixed telangiectasia; being seeded in parallel (implicit stub)
  • niacinamide — topical skin-barrier support in rosacea
  • uv-protection — primary prevention for the vascular/ETR component
  • skin-aging — broader aging skin context
  • chronic-inflammation — primary underlying hallmark

Footnotes

Footnotes

  1. doi:10.1111/bjd.15122 · PMID 27718519 · Tan J, Almeida LM, Bewley A, Cribier B, Dlova NC, et al. · British Journal of Dermatology 2017;176(2):431–438 · consensus statement · ROSCO (Global ROSacea COnsensus) panel; phenotype-based classification framework replacing 4-subtype system; diagnostic features (fixed erythema, phymatous change); major features (flushing, papules/pustules, telangiectasia, ocular signs) ↩

  2. doi:10.1111/bjd.18420 · PMID 31392722 · Schaller M, Almeida LMC, Bewley A, Cribier B, Del Rosso J, et al. · British Journal of Dermatology 2020;182(5):1269–1276 · consensus statement · ROSCO 2019 update; reaffirms phenotype-based approach; adds ocular rosacea diagnostic guidance; 213 citations ↩ ↩2

  3. doi:10.1038/nm1616 · PMID 17676051 · Yamasaki K, Di Nardo A, Bardan A, Murakami M, Ohtake T, Coda A, Dorschner RA, Bonnart C, Descargues P, Hovnanian A, Morhenn VB, Gallo RL · Nature Medicine 2007;13(8):975–980 · n=11 rosacea biopsies + 10 normal controls (human) + mouse injection model · in-vivo + in-vitro · model: human rosacea skin biopsies; BALB/c and C57BL/6 mice · SCTE/KLK5 highly expressed in rosacea epidermis; serine protease inhibitors aprotinin/AEBSF abolish activity; rosacea skin contains LL-37 plus unique cathelicidin fragments (FA-29, others) absent in normal skin; superficial subcutaneous injection of LL-37 (320 µM) or FA-29 induces erythema, vascular dilatation, and neutrophilic infiltrate in mice at 48 h; Camp−/− mice show significantly reduced inflammation; Spink5−/− mice (elevated serine protease) show altered cathelicidin processing mirroring rosacea ↩ ↩2 ↩3

  4. doi:10.1038/jid.2010.352 · PMID 21107351 · Yamasaki K, Kanada K, Macleod DT, Borkowski AW, Morizane S, Nakatsuji T, Cogen AL, Gallo RL · Journal of Investigative Dermatology 2011;131(3):688–697 · in-vitro + biopsy · model: human rosacea skin biopsies + keratinocyte culture · TLR2 mRNA and protein elevated in rosacea lesional skin; TLR2 stimulation induces serine protease upregulation; mechanistically links microbial activation to cathelicidin amplification · gap/no-fulltext-access: PDF could not be retrieved from local archive (DOI resolved to wrong content); claims consistent with known literature ↩

  5. doi:10.1016/j.jaad.2013.05.019 · PMID 23871720 · Coda AB, Hata T, Miller J, Audish D, Kotol P, Two A, Shafiq F, Yamasaki K, Harper JC, Del Rosso JQ, Gallo RL · Journal of the American Academy of Dermatology 2013;69(4):570–577 · in-vivo + in-vitro · multi-component: in-vitro human keratinocytes + 9-day mouse skin + 16-week open-label human (n=49 analyzed) · azelaic acid reduces CAMP (cathelicidin) mRNA and KLK5 mRNA; reduction in stratum-corneum serine protease activity was significant only in the high-baseline-SPA subgroup (n=21, p=0.0008), not the low-baseline subgroup; provides mechanistic rationale for a clinically established treatment; 127 citations [duration/measurement precision cross-checked 2026-06-27 against verified azelaic-acid page] ↩

  6. doi:10.1007/s13555-017-0167-6 · PMID 28243927 · Thibaut de Ménonville S, Rosignoli C, Soares E, Roquet M, Bertino B, Salabert I, Vocanson M, Chavagnat JJ, Cherdun R, Hillion M, Jouy N, Closs B, Aries MF · Dermatology and Therapy 2017;7(2):249–262 · in-vitro + ex-vivo · model: human keratinocytes; skin explants · topical ivermectin inhibits gene expression of cathelicidin (CAMP), KLK5, CXCL1, and TNF-α in keratinocytes; dual mechanism: anti-Demodex + anti-cathelicidin ↩ ↩2 ↩3

  7. doi:10.1016/j.jaad.2013.04.045 · PMID 24229632 · Steinhoff M, Schauber J, Leyden JJ · Journal of the American Academy of Dermatology 2013;69(6):S15–S26 · review · covers neurovascular dysregulation (TRPV1/TRPA1), CGRP/substance P neuropeptide role, cathelicidin axis integration; 371 citations ↩ ↩2 ↩3

  8. doi:10.1159/000526296 · PMID 36310014 · Li J, Wei E, Reisinger A, French LE, Clanner-Engelshofen BM, Reinholz M · Dermatology 2023;239(1):12–31 · systematic review and meta-analysis · n=21 studies (rosacea and blepharitis); topical ivermectin showed the largest Demodex mite-density reduction at 1–3 months; permethrin, TTO, IPL also effective; effect sizes vs Demodex density rather than rosacea lesion counts specifically; supports Demodex as tractable therapeutic target ↩ ↩2

  9. doi:10.12688/f1000research.16537.1 · Buddenkotte J, Steinhoff M · F1000Research 2018;7:1885 · review · UV as a direct cathelicidin inducer + TRPV1/TRPA1 activator; chronic UV drives vascular ectasia via ROS + MMP; gold OA; 202 citations ↩

  10. doi:10.1016/j.jaad.2017.02.040 · Li S, Cho E, Drucker AM, Qureshi AA, Li WQ · J Am Acad Dermatol 2017;76(6):1061–1067.e2 · PMID 28434611 · prospective cohort · n=82,737 women (Nurses’ Health Study II); 14-year follow-up; 4,945 incident rosacea cases · dose-response alcohol–rosacea incidence: HR 1.12 (1–4 g/day) to HR 1.53 (≥30 g/day) vs non-drinkers; white wine and liquor most strongly associated; adjusted for major confounders including sun exposure and smoking ↩

  11. doi:10.1111/jocd.14483 · Liu L, Xue Y, Chen Y et al. · J Cosmet Dermatol 2022;21(7):2954–2961 · PMID 34582097 · systematic review and meta-analysis · 14 eligible studies (PubMed, Embase, Cochrane; through February 2021) · overall alcohol not significantly associated with all-rosacea incidence; phymatous rosacea specifically: OR 4.17 (95% CI 1.76–9.91); authors note possible residual confounding through rosacea severity; calls for additional studies on beverage type and sex differences ↩ ↩2

  12. doi:10.1001/jamadermatol.2015.4240 · Augustynowicz A, Maranda EL, Zullo J, Cai L, Jimenez J · JAMA Dermatol 2016;152(4):379 · PMID 27074357 · commentary / historical analysis · characterises the alcohol-rhinophyma cultural association as “The Bard’s Blunder” — a myth rooted in literary/artistic portraiture rather than causal pathology; notes rhinophyma occurs in lifelong non-drinkers; Univ of Miami Miller School of Medicine · abstract only reviewed ↩

  13. doi:10.1016/j.jaad.2018.12.046 · Second J, Severac F, Paix A, Cribier B · J Am Acad Dermatol 2019;81(1):249–250 · PMID 30630023 · brief report / case-control · n=52 prevalent rhinophyma cases vs n=156 age- and sex-matched dermatologic controls (3:1 matching); Strasbourg Hospital; median age 69 years; male:female ratio 25:1; univariate OR 4.14 (95%CI 1.41–12.15; P=.010) for moderate drinkers; OR 17.33 (95%CI 3.96–75.1; P<.001) for excessive drinkers; multivariate analysis: family history of rhinophyma OR 160.7 (strongest predictor); Type 2 diabetes OR 6.45; authors note alcohol alone insufficient to cause rhinophyma — only a minority of rosacea patients develop phymatous changes ↩

  14. doi:10.1111/bjd.17590 · PMID 30585305 · van Zuuren EJ, Fedorowicz Z, Tan J, van der Linden MMD, Arents BWM, Carter B, Charland L · British Journal of Dermatology 2019;181(1):65–79 · systematic review with GRADE · 152 studies, 20,944 participants; phenotype-based review; GRADE: azelaic acid = high certainty; ivermectin = high certainty; metronidazole = moderate certainty; doxycycline 40 mg MR = moderate-to-high certainty; IPL/laser = low-to-moderate certainty; brimonidine (persistent erythema) = high certainty ↩ ↩2 ↩3

  15. doi:10.1016/j.jaad.2006.11.021 · PMID 17367893 · Del Rosso JQ, Webster GF, Jackson M, Rendon M, Rich P, Torok H, Bradshaw M · Journal of the American Academy of Dermatology 2007;56(5):791–802 · rct · n=537 combined (269 doxycycline 40 mg MR, 268 placebo) from two phase III trials (studies 301 and 302); 16-week treatment; mean lesion-count reduction −11.8 vs −5.9 (study 301) and −9.5 vs −4.3 (study 302); p<0.001 for both comparisons; sub-antimicrobial dose exerts anti-inflammatory effect without antibiotic resistance risk; 220 citations ↩ ↩2

  16. doi:10.1111/jdv.13556 · PMID 26915718 · Tan J, Schöfer H, Araviiskaia E, Audibert F, Kerrouche N, Berg M · Journal of the European Academy of Dermatology and Venereology 2016;30(3):428–434 · observational · n=6,065 total screened (Germany n=3,052, Russia n=3,013; aged 18–65); confirmed rosacea n=119 (Germany 82, Russia 37); adjusted prevalence Germany 12.3% [95%CI 10.2–14.4] vs Russia 5.0% [95%CI 2.8–7.2]; ETR most common subtype (67.2%); 74.8% female; mean age 41.8 years; 142 citations ↩

  17. doi:10.1111/ced.13107 · PMID 28639713 · Dlova NC, Mosam A · Clinical and Experimental Dermatology 2017;42(6):670–671 · observational case series · model: South African patients with skin phototypes V–VI · rosacea occurs in darker phototypes but is underdiagnosed due to difficulty assessing erythema on dark skin; clinical features present but erythema masked ↩

Graph View

Backlinks