TABLE 2.
Mechanisms of skin aging and dermatologic interventions to counteract them.
| Clinical properties | Histological/Molecular changes | Strategy |
|---|---|---|
| Roughness | • Microdermabrasion | |
| SC compaction ↑ | • Superficial chemical peels | |
| Epidermal thickness ↓ | • Microneedling, fractional lasers, FRFM | |
| Epidermal HA ↓ | • AHA, RA, EGF, peptides, estrogen, biopolymers (PDRN, PN) | |
| • Moisturization, LMWHA, acetylated HA | ||
| Solar lentigines | • TCA peels | |
| Elongation of RRs | • Lasers (CO2, Er:YAG, ablative fractional laser) | |
| Mutations of KC/MC genes | • FRFM | |
| MC No. ↑, melanogenesis ↑ | • Selective photothermolysis | |
| • IPL, low-fluence Q-switched Nd:YAG laser | ||
| Wrinkles | Epidermal thickness ↓ | • Microdermabrasion, superficial chemical peels, RA |
| • Microneedling, fractional lasers, FRFM | ||
| ROS → Inflammatory cytokines ↑ | • Antioxidants, exosomes, GFs, PRP, SVF | |
| → MMPs ↑ | • Biopolymers (PDRN, PN) | |
| → Degradation of ECM proteins | • Lasers, IPL, RF, HFUS | |
| • Synthetic polymers (PLA, PCL, PDO) | ||
| More dermal changes in photoaged skin | • Photoprotection | |
| Sagging | ROS → MMPs ↑ | • Antioxidants, biopolymers, synthetic polymers, GFs, HFUS |
| • Fibroblast stimulation by EBDs | ||
| Elastic fiber degeneration | • Biopolymers, synthetic polymers, PRP, SVF | |
| Collagen degradation | • Fat injection, fillers | |
| Remaining disorganized elastic fibers | • Ablative fractional lasers, FRFM | |
| Inelasticity | Solar elastosis | • Repeated chemical peels, topical RA |
| • Ablative fractional lasers, FRFM | ||
| Neutrophil elastase ↑ | • Antioxidants | |
| Edema | Vascular leakage ↑ | • Massage and drainage (mechanical, US, RF, shock wave, acoustic wave) |
| → Fluid retention | ||
| Intervascular distance ↑ (loosely woven collagen network) | • Fibroblast stimulation (EBDs, injectables) | |
| Ectatic vessels with atrophic walls | • Selective photothermolysis, FRFM | |
| Telangiectasia | Collagen and elastic fibers ↓ | • Fibroblast stimulation (EBDs, injectables) |
| Redness | Perivascular inflammation | • Antioxidants, PRP, exosomes, PDRN, PN |
| Purpura | Neurogenic inflammation | • HFUS |
| • Botulinum toxin, mild cryotherapy |
Abbreviations: AHA, alpha-hydroxy acid; EBD, energy-based device; ECM, extracellular matrix; EGF, epidermal growth factor; FRFM, fractional radiofrequency microneedling; GF, growth factor; HA, hyaluronic acid; HFUS, high-frequency ultrasound; IL, interleukin; IPL, intense pulsed light; KC, keratinocyte; LMWHA, low-molecular weight hyaluronic acid; MC, melanocyte; MMP, matrix metalloproteinase; PCL, polycaprolactone; PDO, polydioxanone; PDRN, polydeoxyribonucleotide; PLA, poly (lactic acid); PN, polynucleotide; PRP, platelet-rich plasma; RA, retinoic acid; RF, radiofrequency; ROS, reactive oxygen species; RR, rete ridge; SC, stratum corneum; SVF, stromal vascular fraction; TCA, trichloroacetic acid; TNF, tumor necrosis factor; US, ultrasound.