Creative Touch Permanent Makeup and Aesthetics

Inflammageing is the chronic, low-grade, sterile inflammatory state that accumulates with age – not as a response to infection or injury, but as a consequence of the body’s own ageing biology. Driven by SASP-secreting senescent cells, mitochondrial damage signalling through the cGAS-STING pathway, NLRP3 inflammasome activation, and a progressively imbalanced immune system, it operates below the threshold of clinical illness whilst systematically impairing tissue repair, barrier function, and cellular regenerative capacity. In the skin, dermal fibroblasts are not passive victims of inflammageing but active orchestrators of it – sustaining a macrophage-T cell inflammatory circuit through NF-κB signalling that accelerates the structural changes visible as skin ageing. Inflammageing explains why skin ages faster in some clients than biological age predicts, why regenerative treatments produce variable results in the same client at different life stages, and why treating the inflammatory environment is a clinical priority rather than an optional precondition.

Inflammageing was coined by the gerontologist Claudio Franceschi in 2000 to describe a phenomenon that had been observed in ageing populations but not yet named: the progressive accumulation of a low-level, chronic inflammatory state that increases with age in the absence of infection, overt tissue damage, or identifiable autoimmune trigger. ^[5] The term combines inflammation and ageing deliberately – not merely as wordplay but to capture the bidirectional relationship between the two processes. Inflammation drives ageing; ageing drives inflammation. Once established, the cycle is self-perpetuating. ^[3]

(Note on spelling: the original term appears as both “inflammaging” and “inflammageing” in the literature. This knowledge base uses the British English form throughout, consistent with our language standard.)

What Inflammageing Is

Inflammation in the conventional sense is purposeful and self-limiting – initiated by a pathogen or injury, executed by the immune system, and resolved once the threat is cleared. It has a beginning, a middle, and an end. Inflammageing has none of these properties. It is not initiated by a pathogen; it produces no acute symptoms; and it does not resolve. It persists indefinitely at a subclinical level – below the threshold that would register as illness, above the threshold that allows tissue to function optimally.

The technical distinction that explains this behaviour is the difference between PAMPs and DAMPs. Conventional inflammation is triggered by pathogen-associated molecular patterns (PAMPs) – molecular signatures of bacteria, viruses, and fungi recognised by pattern recognition receptors as foreign. Inflammageing is triggered by damage-associated molecular patterns (DAMPs) – molecular signals released by the body’s own stressed, damaged, or dying cells. These include cytosolic DNA leaked from damaged mitochondria, oxidised lipids, fragmented extracellular matrix components, and HMGB1 released from necrotic cells. DAMPs activate the same pattern recognition receptors as PAMPs – TLR4, TLR9, the NLRP3 inflammasome, the cGAS-STING pathway – but without the resolution mechanism that pathogen clearance provides. The signal does not switch off because the source – ageing biology – does not resolve. ^[2]

The clinical consequence of this subclinical persistence is not dramatic in any individual moment but cumulative and compounding over decades. Tissue repair becomes progressively less efficient, regenerative capacity declines, barrier function deteriorates, and the risk threshold for age-related disease – cardiovascular disease, type 2 diabetes, neurodegeneration, and cancer – is progressively lowered. Inflammageing is not the proximate cause of these conditions but the permissive environment in which they develop more readily.

The Molecular Drivers

Inflammageing is not produced by a single mechanism – it is the aggregate output of several converging biological processes, each of which generates pro-inflammatory signals through different pathways. In practice they amplify each other.

Cellular senescence and SASP

As covered in the Subcutaneous Tissue and Tissue Regeneration entities, senescent cells – those that have entered permanent cell cycle arrest – secrete the senescence-associated secretory phenotype (SASP): a pro-inflammatory mixture of IL-6, IL-8, TNF-α, IL-1β, and MMPs. With age, the burden of senescent cells in tissue increases, partly because senescent cell clearance by the immune system becomes less efficient, and partly because the SASP itself induces senescence in adjacent cells – a paracrine transmission of the senescent state. The result is a progressively expanding source of pro-inflammatory signalling within ageing tissue that grows faster than it is cleared. ^[9]

The cGAS-STING pathway

One of the most significant recent advances in understanding inflammageing mechanistically is the identification of the cGAS-STING pathway as a central bridge between cellular ageing damage and chronic immune activation. cGAS (cyclic GMP- AMP synthase) is a cytosolic DNA sensor – normally a first-line viral defence mechanism that detects double-stranded DNA where it should not be (in the cytoplasm rather than the nucleus). With age, mitochondrial DNA integrity declines; mitochondrial membrane permeability increases; and fragmented mitochondrial DNA leaks into the cytoplasm, where cGAS detects it as a foreign signal and activates STING (stimulator of interferon genes). STING activation drives NF-κB and IRF3 transcription, producing IFN-β and pro-inflammatory cytokines that sustain chronic immune activation from an endogenous source that does not diminish with antibiotic treatment or pathogen clearance. ^[8]

NF-κB: effector and amplifier

Nuclear factor kappa B is the central transcription factor of inflammageing – not because it is the sole mechanism, but because it sits at the convergence point of most of the upstream signals (DAMP recognition, SASP cytokine signalling, cGAS-STING output, oxidative stress) and drives the downstream output (IL-6, IL-8, TNF-α, COX-2, MMP production). Critically, NF-κB activation induces further NF-κB expression – it is self-amplifying. In young tissue, NF-κB activation is balanced by anti-inflammatory resolution mechanisms; in aged tissue, the resolution mechanisms are less efficient and the chronic activation becomes the default state rather than the exception. ^[10]

NLRP3 inflammasome activation

The NLRP3 inflammasome is an intracellular multiprotein complex that assembles in response to DAMPs – including cholesterol crystals, uric acid crystals, ATP released from damaged cells, and the mitochondrial ROS that accumulate with age. Activated NLRP3 processes IL-1β and IL-18 into their active forms, two potent pro-inflammatory cytokines that amplify the broader inflammageing signal. NLRP3 activation is the mechanism through which metabolic stressors – obesity, insulin resistance, dyslipidaemia – feed directly into the inflammageing pathway, explaining the accelerated biological ageing observed in metabolic syndrome. ^[6]

Immunosenescence

The ageing immune system undergoes structural changes that directly worsen inflammageing: innate immune cells become hyperactivated (producing more inflammatory cytokine at lower provocation thresholds) whilst adaptive immune function – particularly the T-cell repertoire – narrows and declines. The regulatory T-cell (Treg) population, which normally suppresses excessive immune activation, becomes less effective with age. The net result is an immune system that produces more inflammatory signal, less discriminately, and resolves it less efficiently – removing the biological brake that would normally terminate the inflammageing cycle. ^[4]

Gut microbiome dysbiosis

With age the gut microbiome shifts toward a less diverse, more gram-negative-dominant composition – increasing intestinal permeability and the translocation of bacterial lipopolysaccharide (LPS) into systemic circulation. LPS is a potent TLR4 agonist; its chronic low-level systemic presence provides a persistent PAMP-derived inflammatory stimulus that compounds the DAMP-driven signals described above. This is one of the mechanistic connections between gut health and skin ageing – systemic LPS-driven TLR4 activation increases NF-κB activity in dermal fibroblasts and keratinocytes, directly contributing to the skin’s local inflammageing burden.

The Skin as Target and Contributor

The skin is not simply damaged by systemic inflammageing – it is both a significant target of it and an active contributor to it. This bidirectionality is the aspect most relevant to aesthetics practice and the least well represented in consumer-facing content.

Dermal fibroblasts as orchestrators

Senescent dermal fibroblasts are among the most prolific SASP producers in aged skin, secreting IL-6, IL-8, MMP-1, and MMP-3 into the dermal microenvironment. Beyond their own SASP output, a September 2025 PMC study identified fibroblastic NF-κB activation as the structural driver of a self-perpetuating dermal inflammageing circuit – activated fibroblasts recruiting macrophages and T-cells into the dermis, establishing tertiary lymphoid-like structures that maintain chronic local immune activation independently of systemic inflammageing status. ^[1] The fibroblast in inflammageing is not a passive cell being damaged by inflammation – it is orchestrating the inflammatory environment that damages it and its neighbours.

The downstream consequences for skin structure are direct: SASP-derived MMP-1 and MMP-3 degrade type I and type III collagen and fibronectin; IL-6 suppresses collagen synthesis whilst promoting collagenase expression; TNF-α suppresses filaggrin and loricrin expression through the c-Jun pathway (as covered in the Psoriasis entity). The visible result is the progressive thinning, laxity, and textural deterioration of intrinsically aged skin – not as a passive consequence of time but as an active output of a sustained inflammatory process in the dermis.

Keratinocyte and melanocyte senescence

Senescent keratinocytes in the epidermis produce IP-10 (CXCL10), which binds CXCR3 receptors on adjacent keratinocytes and induces senescence through paracrine signalling – a bystander effect that propagates the senescent state laterally through the epidermis without requiring each cell to reach replicative exhaustion independently. ^[7] Senescent melanocytes contribute to the uneven pigmentation of photodamaged aged skin – both through altered melanin synthesis regulation and through SASP-driven paracrine effects on surrounding keratinocytes that alter melanin distribution.

The contribution to systemic burden

The dermal SASP output does not stay in the skin. IL-6 and TNF-α secreted by senescent dermal fibroblasts enter systemic circulation, contributing to the systemic inflammageing pool alongside adipose tissue SASP, gut-derived LPS, and mitochondrial DNA-driven cGAS-STING signalling. The skin is a large organ; its aggregate senescent cell SASP contribution to systemic inflammatory burden is not negligible, and represents a genuine mechanistic connection between skin health interventions and systemic inflammatory status – not a marketing claim.

The Hallmarks of Ageing Connection

Inflammageing is not one of the twelve hallmarks of ageing in the Lopez-Otin framework – it is the integrating thread that connects them. Each hallmark generates pro-inflammatory signals through its own mechanism; together they converge on NF-κB and the NLRP3 inflammasome to produce the aggregate inflammageing state. Genomic instability generates DAMPs through nuclear DNA damage and repair byproducts that activate cGAS-STING; telomere attrition triggers DDR (DNA damage response) signalling that activates NF-κB directly; cellular senescence produces SASP; mitochondrial dysfunction generates ROS and cytosolic mtDNA. The hallmarks are not parallel independent processes – they are a converging network, and inflammageing is what they converge on. ^[2]

This framing is covered in full in the Hallmarks of Ageing entity, which provides the framework within which each individual hallmark entity sits. The present entity focuses on inflammageing’s skin-specific manifestations and clinical implications.

What Impairs or Accelerates Inflammageing

Not all skin ages at the same biological rate, and not all of that variation is genetic. Several modifiable factors meaningfully accelerate or attenuate the inflammageing trajectory:

Accelerators

• UV exposure – ultraviolet radiation generates ROS, causes direct DNA damage (producing DAMPs), induces keratinocyte and fibroblast senescence, and activates NF-κB through multiple parallel pathways; it is the single largest modifiable accelerator of skin-specific inflammageing
• Air pollution – particulate matter and polycyclic aromatic hydrocarbons activate AhR (aryl hydrocarbon receptor) in keratinocytes, driving NF-κB and accelerating fibroblast senescence; urban skin ages differently from rural skin for this reason
• Chronic psychological stress – sustained cortisol elevation promotes NF-κB activity, suppresses regulatory T-cell function, and accelerates telomere shortening; the HPA axis is a direct bridge between psychological stress and inflammageing biology
• Sleep deprivation – as referenced in the Filaggrin entity, acute and chronic sleep disruption reduces filaggrin and loricrin expression whilst elevating pro-inflammatory cytokines; the circadian regulation of NF-κB activity means sleep disruption directly dysregulates the central inflammatory effector
• Metabolic syndrome – visceral adipose tissue is a major SASP source; insulin resistance amplifies NLRP3 inflammasome activation; elevated blood glucose generates advanced glycation end-products (AGEs) that activate RAGE receptors and drive NF-κB

Modulators with evidence support

• mTOR inhibition – caloric restriction and intermittent fasting reduce mTOR activity, which reduces SASP expression and extends healthy cellular lifespan in multiple tissue types; the evidence in humans is consistent if not yet definitive on optimal protocols
• Physical activity – regular moderate exercise reduces systemic IL-6 and TNF-α, promotes anti-inflammatory IL-10, and maintains immune regulatory capacity; the anti-inflammageing effect of exercise is one of the most consistently replicated findings in geroscience
• Barrier integrity – a competent skin barrier reduces DAMP exposure from environmental irritants penetrating to viable tissue; barrier disruption itself activates NF-κB in keratinocytes through PAR-2 signalling, making barrier maintenance a direct anti-inflammageing intervention at the skin level
• UV protection – daily broad-spectrum SPF is not a cosmetic preference; it is the most evidence-supported single intervention for reducing skin-specific inflammageing accumulation over time