The Redness That Wouldn't Go Away

📅 April 27, 2026👤 Restorative and Medical Skincare Researcher Simon Finch⏱ 14 min read

The Redness That Wouldn't Go Away

If you are a woman over 60, you may have noticed a change in your skin that goes beyond wrinkles and sagging. Your face, particularly around the cheeks, nose, and chin, may have become persistently pink or red. The sensation of warmth or flushing may come and go unpredictably. Products that once felt soothing now sting. This constellation of symptoms is not your imagination, and it is not a skincare failure. It may be rosacea — a chronic inflammatory condition that becomes more common, and more challenging to treat, after menopause.

Rosacea affects an estimated 16 million people in Europe alone, and its prevalence peaks in women aged 50–70. The condition is characterised by persistent facial erythema (redness), telangiectasia (visible blood vessels), inflammatory papules and pustules, and a subjective sensation of stinging, burning, or tingling. For many postmenopausal women, rosacea represents not a sudden onset but a gradual shift in skin reactivity that makes previously tolerable products and environmental exposures suddenly problematic.

Conventional rosacea treatment relies on topical antibiotics (metronidazole, ivermectin, azelaic acid) and oral tetracyclines. These are effective but carry significant limitations. Antibiotics disrupt the skin microbiome, which may paradoxically worsen long-term skin health. Oral tetracyclines cause photosensitivity and gastrointestinal side effects, and their long-term use raises concerns about antibiotic resistance. Topical ivermectin is effective for papulopustular rosacea but does little for the persistent erythema that bothers many patients. And none of these treatments address the underlying problem: the skin's reduced capacity for repair and its heightened sensitivity to inflammatory triggers.

PDRN offers a fundamentally different approach. Its anti-inflammatory mechanism operates through the A2A adenosine receptor, which suppresses NF-κB activation and reduces the production of pro-inflammatory cytokines (TNF-α, IL-6, IL-1β). This is not a bactericidal effect — PDRN does not kill bacteria. It does not suppress the immune system in a broad, indiscriminate way. Instead, it changes the inflammatory environment in which the disease operates, restoring the skin's natural capacity to respond to triggers without excessive inflammation.

Understanding Rosacea: More Than Just Redness

Rosacea is a complex, multifactorial disorder that involves four interrelated pathological processes: dysregulation of the innate immune system, abnormal neurovascular signalling, disruption of the skin barrier, and proliferation of Demodex mites. No single cause explains all cases, and the relative contribution of each factor varies from person to person.

In postmenopausal women, the loss of oestrogen adds another layer of complexity. Oestrogen has well-documented anti-inflammatory and barrier-supporting effects in the skin. It promotes the production of ceramides — the lipid molecules that form the skin's permeability barrier — and supports the synthesis of hyaluronic acid, which maintains hydration. When oestrogen levels decline after menopause, the skin barrier becomes thinner and more permeable. This allows irritants to penetrate more easily and triggers inflammatory responses that would not occur in younger skin.

The innate immune system plays a central role in rosacea pathogenesis. In affected skin, keratinocytes produce abnormally high levels of cathelicidin antimicrobial peptides, particularly LL-37. These peptides, while normally part of the skin's defence against infection, become dysregulated in rosacea and directly contribute to the inflammatory response. Their production is controlled by kallikrein 5 (KLK5), a serine protease that processes cathelicidin into its active form. In rosacea, KLK5 activity is elevated, leading to excessive LL-37 production.

This is where PDRN's mechanism becomes relevant. The A2A adenosine receptor, when activated, triggers a signalling cascade that can suppress the production of pro-inflammatory mediators, including those involved in the cathelicidin pathway. By dampening the inflammatory response at its source, PDRN may reduce the activity of the innate immune dysregulation that drives rosacea.

The A2A Adenosine Receptor: A Master Regulator of Inflammation

To understand how PDRN works in rosacea, you need to understand the A2A adenosine receptor. It is one of four adenosine receptor subtypes (A1, A2A, A2B, A3) expressed on the surface of cells throughout the body. These receptors are part of the G protein-coupled receptor (GPCR) family — the largest and most druggable family of cell surface receptors in the human genome.

The A2A receptor is expressed on a wide range of cell types relevant to rosacea: keratinocytes, fibroblasts, endothelial cells, mast cells, macrophages, and T lymphocytes. Its natural ligand is adenosine, a molecule that is produced when ATP is broken down in the extracellular space. Adenosine levels rise in damaged or inflamed tissues, serving as a natural signal that activates anti-inflammatory and tissue-protective responses.

The Signalling Cascade: From Receptor to Anti-Inflammatory Effect

When adenosine binds to the A2A receptor, it triggers a change in the receptor's shape that activates an associated G protein (Gs). This G protein, in turn, activates adenylyl cyclase, an enzyme that converts ATP into cyclic AMP (cAMP). The increase in intracellular cAMP activates protein kinase A (PKA), which phosphorylates a variety of downstream targets.

One of the most important targets of PKA is the transcription factor CREB (cAMP response element-binding protein). When phosphorylated by PKA, CREB translocates to the nucleus and drives the expression of anti-inflammatory genes, including IL-10 and the suppressor of cytokine signalling (SOCS) family.

But the anti-inflammatory effects of A2A signalling go beyond CREB activation. PKA also phosphorylates and inhibits the transcription factor NF-κB — the master regulator of the inflammatory response. NF-κB controls the expression of hundreds of pro-inflammatory genes, including TNF-α, IL-1β, IL-6, IL-8, and cyclooxygenase-2 (COX-2). When PKA inhibits NF-κB, the expression of all these genes is reduced, producing a broad-spectrum anti-inflammatory effect.

This mechanism is fundamentally different from how topical antibiotics or corticosteroids work. Antibiotics kill bacteria, which reduces the antigenic stimulus for inflammation. Corticosteroids bind to glucocorticoid receptors and broadly suppress immune function through genomic and non-genomic mechanisms. The A2A pathway, by contrast, restores the natural balance of inflammatory signalling without suppressing the immune system's ability to respond to genuine threats.

How PDRN Activates the A2A Pathway

PDRN is a mixture of long-chain deoxyribonucleotides. When applied topically to the skin, it is broken down by cellular enzymes into individual deoxyribonucleosides — molecules composed of a nitrogenous base (adenine, guanine, cytosine, or thymine) attached to a deoxyribose sugar. Among these, deoxyadenosine is of particular interest for inflammation.

Deoxyadenosine is converted to adenosine through the action of adenosine deaminase and other metabolic enzymes. The adenosine thus generated is released into the extracellular space, where it can bind to the A2A receptor on the surface of skin cells. The concentration of adenosine achieved through this pathway depends on the amount of PDRN applied and the activity of the metabolic enzymes in the skin.

Critically, the adenosine generated from PDRN is produced locally, within the skin tissue itself. This means that the anti-inflammatory effect is concentrated at the site of application, without the systemic effects that would accompany oral adenosine-like drugs. This localised action makes topical PDRN particularly well-suited for the treatment of inflammatory skin conditions like rosacea.

The Menopause Connection: Why Rosacea Changes at 60+

The relationship between menopause and rosacea is not coincidental. Both conditions involve changes in vascular reactivity, immune function, and skin barrier integrity. Understanding this connection is essential for choosing the right treatment approach.

Vascular Reactivity and Hot Flushes

Menopause is characterised by a loss of oestrogen, which affects vascular tone through multiple mechanisms. Oestrogen promotes the production of nitric oxide (NO), a potent vasodilator that helps maintain healthy blood flow. When oestrogen declines, NO production decreases, and the vascular system becomes less adaptable. This contributes to the hot flushes and night sweats that affect up to 80% of postmenopausal women.

In the skin, this vascular dysregulation contributes to the flushing and persistent erythema of rosacea. The blood vessels of the face dilate more easily in response to triggers such as temperature changes, spicy foods, or emotional stress. When this flushing becomes chronic, the vessels themselves become permanently dilated — the telangiectasia that characterises advanced rosacea.

PDRN's effects on the A2A adenosine receptor may help modulate this vascular response. Adenosine signalling through the A2A receptor can reduce the sensitivity of blood vessels to vasodilatory stimuli, potentially reducing the frequency and severity of flushing episodes.

Barrier Dysfunction and Sensitivity

The skin barrier — the outermost layer of the epidermis, known as the stratum corneum — is composed of corneocytes (flattened, dead skin cells) embedded in a lipid matrix of ceramides, cholesterol, and free fatty acids. This structure provides both a physical barrier against environmental irritants and a permeability barrier that prevents excessive water loss.

Oestrogen plays a critical role in maintaining the skin barrier. It stimulates the production of ceramides by keratinocytes and promotes the synthesis of filaggrin, a protein that is broken down into natural moisturising factors. After menopause, ceramide levels in the stratum corneum decline by up to 30%, and skin barrier function deteriorates accordingly.

A compromised barrier allows irritants — including bacteria, allergens, and environmental pollutants — to penetrate the skin more easily. Once inside, these irritants trigger inflammatory responses that further damage the barrier, creating a vicious cycle. This is why postmenopausal women with rosacea often report that their skin has become sensitive to products they have used for years.

PDRN can help break this cycle. By reducing inflammation through the A2A pathway, PDRN may allow the skin barrier to repair itself more effectively. Sohn and colleagues (2023) demonstrated that topical PDRN significantly accelerated skin barrier recovery after controlled disruption, with treated skin showing improved transepidermal water loss (TEWL) values and re-epithelialisation rates compared with untreated controls. This barrier-supporting effect may be particularly valuable for postmenopausal women whose skin's natural repair capacity is compromised.

Immune Senescence and Inflammaging

The aging immune system undergoes profound changes, collectively known as immunosenescence. The adaptive immune system — the T and B cells that provide targeted, memory-based immunity — becomes less effective with age. But the innate immune system, which provides immediate, non-specific defence, becomes chronically activated.

This shift toward innate immune activation contributes to inflammaging — the chronic, low-grade inflammation that characterises aging tissues. In the skin, inflammaging manifests as elevated levels of pro-inflammatory cytokines, increased MMP activity, and a reduced capacity for wound healing. For women with rosacea, inflammaging means that the baseline level of skin inflammation is higher, making flare-ups more likely and more severe.

PDRN's anti-inflammatory mechanism is particularly relevant in the context of inflammaging. By activating the A2A receptor and suppressing NF-κB, PDRN can reduce the elevated baseline inflammatory tone of aged skin, potentially preventing the kind of exaggerated inflammatory responses that characterise rosacea flare-ups.

PDRN vs. Conventional Rosacea Treatments: A Mechanistic Comparison

The Clinical Evidence for PDRN in Inflammatory Skin Conditions

While large-scale clinical trials specifically examining PDRN in rosacea have not yet been published, the existing evidence supports its potential. Several lines of evidence converge to suggest that topical PDRN is a promising option for the management of inflammatory skin conditions in older women.

Chung and colleagues (2022) conducted a randomised controlled trial of topical PDRN in 76 postmenopausal women. While the primary endpoints were skin elasticity and hydration — not inflammatory markers — the study observed that PDRN-treated skin showed reduced erythema compared with placebo. In participants who reported baseline facial redness or sensitivity, PDRN application was associated with a noticeable reduction in these symptoms by week 8 of the 12-week study.

Kim and colleagues (2023) compared once-daily versus twice-daily PDRN application in a similar population. The twice-daily group showed significantly greater improvement in skin barrier function, as measured by TEWL, and a more pronounced reduction in visible redness. This dose-response relationship supports the mechanistic model: more frequent PDRN application leads to more sustained A2A receptor activation and greater anti-inflammatory benefit.

Importantly, no study has reported significant adverse effects from topical PDRN. The ingredient is well-tolerated even on sensitive skin, with no reported cases of contact dermatitis, stinging, or burning. This tolerability profile is particularly important for postmenopausal women with rosacea, whose skin is often too sensitive to tolerate standard prescription treatments.

PDRN and the Skin Microbiome

One of the most interesting aspects of PDRN's anti-inflammatory mechanism is its compatibility with the skin microbiome. Unlike topical antibiotics, which kill both pathogenic and commensal bacteria, PDRN has no antimicrobial activity. It does not disrupt the delicate ecosystem of microorganisms that live on the skin's surface.

This is significant for several reasons. First, the skin microbiome plays an important role in maintaining barrier function and regulating immune responses. Disruption of the microbiome by antibiotics can lead to dysbiosis, which may worsen inflammatory skin conditions in the long term.

Second, there is emerging evidence that the gut-skin axis — the bidirectional communication between the gastrointestinal microbiome and the skin — influences the severity of rosacea. Oral antibiotics used for rosacea disrupt the gut microbiome as well as the skin microbiome, potentially affecting this gut-skin communication. PDRN, by avoiding any antibacterial effect, preserves both skin and gut microbiomes.

Third, the use of antibiotics for chronic conditions like rosacea raises legitimate concerns about antibiotic resistance. While topical antibiotics are less likely to induce resistance than oral antibiotics, they are not risk-free. PDRN's non-antibiotic mechanism offers an alternative that does not contribute to the growing problem of antimicrobial resistance.

Practical Application: Using PDRN for Rosacea and Sensitive Skin

If you are a woman over 60 with rosacea or sensitive skin, incorporating PDRN into your routine requires a thoughtful approach. Here are evidence-informed recommendations based on the mechanistic understanding we have discussed.

Start with a Simple Protocol

When introducing any new product to sensitive skin, less is more. Begin with a single PDRN product — a serum or toner — applied once daily to clean, dry skin. Apply to the entire face, focusing on areas of visible redness or sensitivity. If tolerated after one week, increase to twice-daily application.

The twice-daily protocol is supported by the comparative study by Kim and colleagues (2023), which found superior results with twice-daily application. The mechanistic rationale is straightforward: adenosine generated from PDRN is metabolised within minutes to hours, so maintaining effective tissue levels requires regular application.

Layer Carefully with Other Products

For sensitive skin, the order of product application matters. Apply PDRN serum immediately after cleansing, while the skin is still slightly damp. This allows the nucleotides to be absorbed before heavier products are applied. Wait at least 2–3 minutes before applying moisturiser, to allow the PDRN to penetrate.

Avoid layering PDRN with products containing high concentrations of acids (glycolic, salicylic, lactic) or strong retinoids on the same application. While PDRN can be used alongside these ingredients in a complete routine, applying them simultaneously may reduce PDRN's absorption or increase irritation. A practical approach is to use PDRN in the morning and retinoids or acids in the evening.

Be Patient

The anti-inflammatory effects of PDRN are not immediate. Unlike topical corticosteroids, which produce visible effects within days, PDRN works gradually by restoring the skin's own regulatory mechanisms. In the clinical trials showing the greatest anti-inflammatory benefit, significant improvements were observed after 8–12 weeks of consistent use.

This gradual onset of effect is actually a sign that the mechanism is working as intended. Rather than suppressing inflammation through pharmacological force, PDRN supports the skin's natural capacity to regulate its own inflammatory responses. The changes are slower but more sustainable.

Combine with Barrier-Supporting Ingredients

PDRN works synergistically with ingredients that support the skin barrier. Ceramide-containing moisturisers help restore the lipid matrix of the stratum corneum, complementing PDRN's effects on barrier repair. Niacinamide (vitamin B3) supports ceramide synthesis and has anti-inflammatory effects that may add to PDRN's benefits.

For daytime use, a mineral sunscreen (containing zinc oxide or titanium dioxide) is essential for rosacea-prone skin. UV radiation is a potent trigger for inflammation in rosacea, and physical sunscreens provide broad-spectrum protection without the chemical irritants that can trigger stinging and burning.

When PDRN May Not Be Enough

PDRN is a powerful anti-inflammatory ingredient, but it is not a cure for rosacea. For some individuals, particularly those with moderate to severe papulopustular rosacea, prescription medications may still be necessary. PDRN can be used alongside these treatments without interference, potentially allowing lower doses of prescription medications to be effective.

If you have been diagnosed with rosacea and your current treatment is not providing adequate control, adding PDRN to your routine may help. Always discuss any new skincare ingredients with your dermatologist, particularly if you are using prescription medications or have a complex medical history.

For the many postmenopausal women who cannot tolerate standard rosacea treatments — or whose symptoms are primarily erythema and sensitivity rather than papules and pustules — PDRN offers a well-tolerated, mechanistically grounded option that addresses the underlying inflammatory and barrier dysfunction at the root of their symptoms.

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