What it means for a patient
- Lasers are sometimes used on scars. This review describes how controlled laser heat may help skin heal.
- The effect depends on laser type and settings. The authors state the benefit depends on controlled use.
- This is a review. The abstract gives no patient results or numbers beyond temperature.
- Ask your doctor what evidence supports laser treatment of your scar.
Why this paper matters
It set out a proposed mechanism, the heat shock response and growth factor changes, for how thermal lasers might improve wound healing. It frames controlled laser heat as a possible aid to scar revision and wound repair.
Overview
Lasers are used for skin lesions, scar revision, tissue welding and wrinkle removal, all by producing heat. The authors review how laser heat affects the skin around the treated area and whether it can promote wound healing. They draw on experimental and clinical studies.
Findings
- Laser effect (vaporizing, coagulating or heating tissue) is controlled by wavelength and settings.
- Well-absorbed lasers (far-infrared, such as CO2 and Er:YAG) make shallow, intense heat; less-absorbed lasers (visible or near-infrared) make deeper, milder heat.
- Regardless of laser type, surrounding skin reaches a temperature gradient of 45 to 50 degrees C.
- Any healing effect comes from live cells reacting to this modest temperature rise.
- This heat induces a heat shock response, a quick, temporary change in cell metabolism that produces heat shock proteins.
- Heat shock protein 70 rises after laser treatment and may act together with growth factors such as TGF-beta.
- TGF-beta is key to inflammation and scar tissue formation; fibroblasts produce collagen and matrix in this process.
- The authors conclude thermal lasers could promote skin wound healing if used in a controlled manner.
Terms
- Thermal laser: a laser that works by converting light into heat in tissue.
- Heat shock response: a short-term change in cells exposed to heat stress.
- Heat shock proteins (HSP): proteins cells make in response to heat stress.
- TGF-beta (transforming growth factor beta): a signaling protein that drives inflammation and scar formation.
- Fibroblasts: cells that make collagen and help repair wounds.
- Coagulation: heat-induced firming of tissue.
- Hypertrophic and keloid scars: raised scars, within or beyond the wound edge.
- Tissue welding: using laser heat to join tissue edges.