Table 1.

Procedures for atrophic postacne scars.

Procedure and techniques			Advantages		Disadvantages
Vascular lasers or light
	PDLa, KTPb, EDLc, and IPLd	Improve SAEe and may induce collagen remodeling		PIHf
Ablative lasers
	Ablative CO2g and Er:YAGh	Remove epidermis and part of the dermis, allowing collagen remodeling and re‐epithelialization		Persistent erythema, hypopigmentation, PIH, infection, scarring, and long recovery period
Fractional ablative lasers
	Fractional CO2, 2940-nm Er:YAG, 2790-nm Er:YSGGi, 1540-nm Er:glassj, and 1550-nm EDL	Faster recovery, safer in darker skin phototypes, and less dyschromia		Poor results for ice-pick scars, erythema, PIH, and procedural discomfort
Nonablative lasers
	Q-switched Nd:YAGk, diode, and picosecond 755-nm Alexandrite	Dermal thermal injury while preserving epidermis; minimal side effects: short erythema and minimal pain, swelling, oozing, scarring, or downtime		Results are modest and less impressive
RFl
	Fractional RF +/– needling	Create zones of thermal wounds to stimulate dermal remodeling; microneedle bipolar RF and fractional RF offer the best results for ice-pick and boxcar scars with no PIH		Transient pain, erythema, and scabbing
Needling
	Needling device rolled over skin	Low cost, well tolerated, increase transepidermal absorption of topical agents, short recovery period, and low PIH		The full result may take 8 to 12 months as the deposition of new collagen takes place slowly
Dermabrasion and microdermabrasion
	High‐speed brush, diamond cylinder, fraise, silicon carbide sandpaper, and abrasive crystals	Mechanical resurfacing procedures target scar edges precisely without thermal injury		Not effective for ice-pick or deep boxcar scars
Chemical peels
	Glycolic acid, lactic acid, salicylic acid, mandelic acid, TCAm, and phenol	Induce chemical injury to the skin that stimulates collagen remodeling		Prolonged erythema, infection, PIH, and scarring in darker skin phototypes, deeper peels, and sun exposure; phenol has cardiac toxicity related to systemic absorption
PRP and stem cell therapy
	Autologous PRPn, MSCso, and adipose tissue–derived MSCs	Enhance wound healing through the release of growth factors, cytokines, and chemokines		Better when combined with skin needling or fractional laser
Filler
	HAp fillers, PLLq, and CaHAr	Address the volume loss resulting from atrophic acne scars		Lumpiness and temporary results, making repeated treatments necessary, which increases cost
Individual atrophic scars surgical management
	Punch excision	Suitable for ice-pick scars and small (<3 mm) boxcar scars +/– sutures along relaxed skin tension lines		Secondary widening of the scar may occur
	Elliptical excision	More favorable than punch excision in larger scars		Secondary scar may occur
	Punch elevation	For boxcar scars		Better when followed by fractional CO2 laser
	Subcision	A blade is used to cut fibrotic strands tethering the scar		Bruising, swelling, bleeding, and infection
	RF-assisted subcision	Comparable to convention subcision with no hematoma		Entry point burn
	Microplasma RF technology combined with subcision	Satisfactory results with relatively no adverse effects		Short-term pain, edema, erythema, scaling, and effusion

^aPDL: pulsed dye laser.

^bKTP: potassium titanyl phosphate.

^cEDL: erbium-doped fractional laser.

^dIPL: intense pulsed light.

^eSAE: scars-associated erythema.

^fPIH: postinflammatory hyperpigmentation.

^gCO₂: carbon dioxide.

^hEr:YAG: erbium-doped yttrium aluminum garnet.

ⁱEr:YSGG: erbium-doped yttrium scandium gallium garnet.

^jEr:glass: erbium glass.

^kNd:YAG: neodymium-doped yttrium aluminum garnet.

^lRF: radiofrequency.

^mTCA: trichloroacetic acid.

ⁿPRP: platelet-rich plasma.

^oMSC: mesenchymal stem cell.

^pHA: hyaluronic acid.

^qPLL: poly-ι-lactic acid.

^rCaHA: calcium hydroxylapatite.