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Laser Revision Of Scars

Laser Revision Of Scars

Article Author:
Anny Xiao
Article Editor:
Leila Ettefagh
9/27/2020 4:35:10 PM
For CME on this topic:
Laser Revision Of Scars CME
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Laser Revision Of Scars


Scars are the result of the cutaneous wound healing process that leads to fibrosis and altered skin morphology. All wounds heal with some degree of scar formation, and a variety of different scars can develop following surgery, trauma, and cutaneous inflammatory processes.[1] Scars can have significant cosmetic, physical, and psychological impacts on patients, prompting many to seek treatment. Various treatment modalities have been utilized, with increasing evidence demonstrating the efficacy of lasers in improving different varieties of scars, including keloids, hypertrophic scars, atrophic scars, and acne scars.[2]Modern advancements in laser technology have enhanced the ability of laser devices to improve the appearance, symptoms, texture, and pliability of all scar types.

Anatomy and Physiology

Scar formation occurs due to cutaneous dermal injury and is under the influence of various etiologic factors: genetic predisposition; depth, type, and location of the skin injury; the degree of tension; local infection or inflammation; and hormonal influences.[3][4]

Hypertrophic scars and keloids characteristically demonstrate abnormal fibroblast proliferation and excessive collagen production in response to a range of skin injuries, often arising with a familial tendency.[5] Hypertrophic scars and keloids occur most commonly in those ages 10 to 30, with males and females equally affected.[4] Keloids occur with a higher prevalence in African-American, Hispanic, and Asian populations with an incidence of 4 to 16%.[6]

Hypertrophic scars are the result of excessive collagen synthesis with insufficient collagen lysis during the remodeling phase, which leads to the formation of thick, hyalinized collagen bundles of fibroblasts and fibrocytes.[5] In keloids, increased production of transforming growth factor (TGF)-beta results in a prolonged proliferative phase of wound healing and significantly increased collagen synthesis by fibroblasts.[7]

In contrast, atrophic scars are characterized by dermal depressions that develop as a result of collagen destruction induced by cutaneous inflammation.[8] This type of scar commonly occurs in inflammatory diseases, such as acne vulgaris, varicella, and lupus, but may also be the result of surgery or trauma. Atrophic scars occur most commonly in patients with acne vulgaris, which affects up to 80% of those ages 11 to 30.[2] Atrophic scars are three times as common as keloids or hypertrophic scars[9]. Atrophic scars result from diminished deposition of collagen factors due to an imbalance between the synthesis of scar matrix components and their degradation by proteases.[9]


Indications for laser scar revision include atrophic, hypertrophic, and keloid scars in patients who desire an improvement in scar appearance and texture. 

Hypertrophic scars are red or pink, firm, raised scars that remain within the border of the initial injury. They form within the first month after the initial injury and may regress over time.[2] Keloids are pink to purple, nodular, firmer scars that extend beyond the margins of the original wound. They may occur weeks to years after the initial injury and do not regress spontaneously.[2] Atrophic scars subclassify into ice pick, boxcar, and rolling scars. Ice pick scars are narrow, deep, sharply marginated tracts that taper to a point at the base and extend vertically to the deep dermis or subcutaneous tissue.[2] Boxcar scars are round to oval depressions that are wider than ice-pick scars with sharply demarcated vertical edges. Rolling scars are wider than icepick or boxcar scars and characteristically show an undulating appearance of the skin due to abnormal fibrous tethering of the dermis to the subcutis.[9]


Contraindications to laser therapy include the use of oral retinoids within the past year, pregnancy or breastfeeding, immunosuppression, connective tissue disorders, and the presence of any concomitant skin disease at the site of treatment. It is important to elicit information regarding herpes simplex virus (HSV) history so prophylactic antiviral therapy can commence before the laser treatment.


  • The laser machine
  • Digital camera
  • Tray with a local anesthetic, post-laser emollient cream, anti-irritation gel, measurement tape


  • The dermatologist
  • Aesthetic medicine specialist
  • Plastic surgeon
  • Dermatology nurse
  • Laser technician/ technologist
  • Aesthetic technologist


Scars should be thoroughly evaluated using a combination of clinical assessment and patient history to guide the appropriate treatment plan. Scars should be categorized as hypertrophic, keloidal, atrophic, or conventional. History of the scar should be obtained to elucidate the age of the scar, previous scar treatments, and type of preceding trauma, surgery, or inflammatory process. The patient's Fitzpatrick skin phototype should be a consideration.

Pictures and measurements taken before each laser treatment can assist in monitoring progress and response to treatment. Scars should be clinically assessed at each visit, documenting pigmentation, pliability, and height of the scar.

Application of a topical anesthetic (e.g., a cream) to the scar should take place between 30 and 60 minutes before beginning treatment. The treatment area should be cleaned with an antiseptic solution before delivering laser treatment.


Laser scar revision utilizes photothermal energy to target intra- and extra-cellular structures within scar tissue to stimulate eventual remodeling of dermal collagen and elastin.

Various types of lasers have been utilized in the treatment of scars since the 1980s, beginning with continuous-wave argon, CO2, and Nd:YAG 1064 lasers, followed by the application of PDL and Er:YAG lasers for scar revision.[10] Most recently, fractional photothermolysis with ablative and non-ablative fractionated lasers have found use as effective treatments for scars.[2]

For hypertrophic scars and keloids, the most common non-ablative laser has been the pulsed dye laser (PDL: 585 to 595 nm).[2] PDL is effective in improving the vascularity, pliability, color, and height of hypertrophic scars and keloids.[11] Previous studies have reported a 57% to 83% improvement in clinical appearance and texture of hypertrophic scars after one to two PDL treatments.[12]

For atrophic facial scars, the most commonly used non-ablative lasers are Nd: YAG and 1450-nm diode laser. One study reported an improvement of 40 to 45% with 1320-nm Nd: YAG or 1450-nm diode laser treatment after an average of three consecutive monthly treatment sessions, as assessed by patient satisfaction surveys, histologic evaluations, and skin texture measurements.[2] Non-ablative lasers have minimal downtime and produce gradual results, with the most significant improvement noted between 3 and 6 months following the final laser treatment.[2]

Non-ablative fractional lasers (NAFL) have been shown to significantly improve the pigmentation and thickness of surgical scars, atrophic scars, hypertrophic scars, and hypopigmented scars.[13] A study by Tierney et al. comparing 1550-nm NAFL to 595-nm PDL for the treatment of surgical scars showed that NAFL outperformed PDL and 83% of patients preferred the half of the scar treated with a non-ablative fractional laser.[13][14] A study by Niwa et al. examined NAFL in the treatment of hypertrophic scars and found 26% to 75% clinical improvement after two to three treatment sessions done at 4-week intervals.[10]

Ablative laser resurfacing, with CO2 or Er: YAG lasers, has been shown to be effective for traumatic and surgical scars, especially when resurfaced within 6 to 10 weeks after trauma or surgery or even immediately after surgery.[15] CO2 and Er:YAG lasers are also effective for atrophic scars due to their ability to smooth scar texture and stimulate collagen production within facial atrophic scars,[16] although patients must consider the potential for significant downtime as re-epithelialization typically takes 4 to 7 days with Er: YAG and 7 to 10 days with the CO2 laser. While requiring more downtime, ablative lasers usually produce a higher degree of clinical improvement.

For acne scars, previous head-to-head studies have suggested that CO2 laser produces superior results while Er: YAG is better tolerated with less downtime.[17] Raised scars and shallow boxcar scars improve the most with laser resurfacing, while icepick scars are more challenging to treat and may necessitate secondary resurfacing.[15] Non-ablative lasers are also useful for acne scars.

More recently, fractional ablative laser resurfacing has emerged as a popular treatment modality for atrophic and surgical scars. In fractional ablative resurfacing, columns of thermal damage, called microscopic thermal treatment zones, are separated by surrounding untreated skin, resulting in rapid re-epithelialization and reduced downtime as only a fraction of skin is altered.[18] The microthermal treatment zones also allow fractional lasers to penetrate the skin more deeply than fully ablative lasers.[19] A double-blinded split-scar study by Tidwell et al. reported a significantly superior outcome with fractionated Er: YAG compared to fully ablative Er: YAG for surgical scar revision, with 94% of patients preferring the side of the scar treated with fractional ablative resurfacing.[19] Another study showed fractional CO2 laser to be effective in treating atrophic traumatic scars in 70% of patients treated with six monthly sessions of fractional CO2 laser treatment.[18]


Adverse effects of non-ablative laser options are generally mild and include transient erythema, which resolves within 24 hours. Blistering, crusting, scarring, and post-inflammatory hyperpigmentation are rare and occur most commonly in darker skin types.[2] The most frequently encountered side effect of PDL treatment is post-treatment purpura lasting for up to one week.[20]

Non-ablative fractional resurfacing laser adverse effects include mild to moderate pain during treatment, and erythema and edema post-treatment lasting up to two to four days.[15]

Side effects of ablative laser resurfacing include temporary burning discomfort, oozing, crusting, ulceration, erythema, edema, acneiform eruptions, eczematous dermatitis, and infections.[15] Long-term adverse effects include dyspigmentation and scarring.[18] Erythema and edema typically worsen within the first 24 to 48 hours after treatment, with erythema occasionally lasting up to 4 months post-treatment. One study reported an average duration of post-treatment erythema for one month.[21] Transient postinflammatory hyperpigmentation occurs 2 to 4 weeks after treatment and is more common in darker skin phototypes. In a study of patients with Fitzpatrick skin types III to V, 45.5% developed transient hyperpigmentation that resolved within three months in 90% of affected patients.[21]

Fractional ablative laser resurfacing adverse effects are generally transient and less severe than with fully ablative resurfacing.[20][18] Erythema, crusting, burning sensation, edema, and bruising were reported after fractional CO2 laser treatment.[18] Persistent erythema and postinflammatory pigmentary changes are less common complications when compared to fully ablative skin resurfacing.[18]

Clinical Significance

Laser therapy for the treatment is an effective and safe treatment modality for multiple types of scars. Several studies have demonstrated high patient satisfaction rates with the cosmetic outcome of various laser treatments. The emergence of fractional ablative laser devices has led to superior outcomes with decreased downtime compared to traditional fully ablative lasers, thereby increasing the appeal of laser treatment for patients. In addition to making existing scars less noticeable, laser therapy can also be used prophylactically to minimize post-operative scarring.[11] For symptomatic scars, lasers can reduce pruritus and pain. Lastly, laser treatment can increase the range of motion of debilitating scars that restrict movement.

Enhancing Healthcare Team Outcomes

Scar revision using laser technology is an interprofessional process that involves the interplay of the primary caregiver, nurse practitioner, surgeon, and a dermatologist, with a special interest in aesthetics in order to achieve the best possible outcome for the patient. Primary healthcare professionals should refer patients with scars to a board-certified dermatologist or plastic surgeon with the necessary medical expertise and specialized knowledge in treating scars with lasers. A medical consultation to review the patient's overall health, comorbidities, skin type, and scar characteristics is essential to treat a scar effectively. The outcomes of patients with scars are variable. While in some cases, skin aesthetics can improve cosmesis, lasers themselves can cause several complications that can worsen the appearance of scars. Hence, laser therapy for scars requires professionals with experience with this device. The nurse has a crucial role to address the patient's fears and concerns before the day of surgery and assists the clinician in providing education for the patient. A follow-up of laser therapy in scar treatment requires an interprofessional approach with liaison between the dermatologist and nursing staff with specialized training in dermatology, as the nurse may well be the initial point of contact and education for follow-up care. This team approach can ensure the best possible patient outcomes. [Level 5]

Nursing, Allied Health, and Interprofessional Team Interventions

Ensure that the patient gives informed consent and is aware of the potential complications of the laser. In addition, the nurse should note the site of the surgery and also record the findings in the chart.

Nursing, Allied Health, and Interprofessional Team Monitoring

  • Vital signs
  • Wound care
  • Monitor for signs of infection
  • Monitor for signs of skin irritation


[1] English RS,Shenefelt PD, Keloids and hypertrophic scars. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.]. 1999 Aug;     [PubMed PMID: 10491047]
[2] Khatri KA,Mahoney DL,McCartney MJ, Laser scar revision: A review. Journal of cosmetic and laser therapy : official publication of the European Society for Laser Dermatology. 2011 Apr;     [PubMed PMID: 21401378]
[3] Alster TS, Laser treatment of hypertrophic scars, keloids, and striae. Dermatologic clinics. 1997 Jul;     [PubMed PMID: 9189679]
[4] Niessen FB,Spauwen PH,Schalkwijk J,Kon M, On the nature of hypertrophic scars and keloids: a review. Plastic and reconstructive surgery. 1999 Oct;     [PubMed PMID: 10513931]
[5] Wolfram D,Tzankov A,Pülzl P,Piza-Katzer H, Hypertrophic scars and keloids--a review of their pathophysiology, risk factors, and therapeutic management. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.]. 2009 Feb;     [PubMed PMID: 19215252]
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[7] Shah M,Foreman DM,Ferguson MW, Neutralising antibody to TGF-beta 1,2 reduces cutaneous scarring in adult rodents. Journal of cell science. 1994 May;     [PubMed PMID: 7929624]
[8] Tanzi EL,Alster TS, Laser treatment of scars. Skin therapy letter. 2004 Jan;     [PubMed PMID: 14716440]
[9] Fabbrocini G,Annunziata MC,D'Arco V,De Vita V,Lodi G,Mauriello MC,Pastore F,Monfrecola G, Acne scars: pathogenesis, classification and treatment. Dermatology research and practice. 2010;     [PubMed PMID: 20981308]
[10] Niwa AB,Mello AP,Torezan LA,Osório N, Fractional photothermolysis for the treatment of hypertrophic scars: clinical experience of eight cases. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.]. 2009 May;     [PubMed PMID: 19389105]
[11] Nouri K,Rivas MP,Stevens M,Ballard CJ,Singer L,Ma F,Vejjabhinanta V,Elsaie ML,Elgart GW, Comparison of the effectiveness of the pulsed dye laser 585 nm versus 595 nm in the treatment of new surgical scars. Lasers in medical science. 2009 Sep;     [PubMed PMID: 19572180]
[12] Keaney TC,Tanzi E,Alster T, Comparison of 532 nm Potassium Titanyl Phosphate Laser and 595 nm Pulsed Dye Laser in the Treatment of Erythematous Surgical Scars: A Randomized, Controlled, Open-Label Study. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.]. 2016 Jan;     [PubMed PMID: 26673432]
[13] Tierney E,Mahmoud BH,Srivastava D,Ozog D,Kouba DJ, Treatment of surgical scars with nonablative fractional laser versus pulsed dye laser: a randomized controlled trial. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.]. 2009 Aug;     [PubMed PMID: 19250300]
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[16] You HJ,Kim DW,Yoon ES,Park SH, Comparison of four different lasers for acne scars: Resurfacing and fractional lasers. Journal of plastic, reconstructive     [PubMed PMID: 26880620]
[17] Alexiades M, Laser and light-based treatments of acne and acne scarring. Clinics in dermatology. 2017 Mar - Apr;     [PubMed PMID: 28274357]
[18] Keen A,Sheikh G,Hassan I,Jabeen Y,Rather S,Mubashir S,Latif I,Zeerak S,Ahmad M,Hassan A,Ashraf P,Younis F,Saqib N, Treatment of post-burn and post-traumatic atrophic scars with fractional CO{sub}2{/sub} laser: experience at a tertiary care centre. Lasers in medical science. 2018 Jul;     [PubMed PMID: 29473114]
[19] Tidwell WJ,Owen CE,Kulp-Shorten C,Maity A,McCall M,Brown TS, Fractionated Er:YAG laser versus fully ablative Er:YAG laser for scar revision: Results of a split scar, double blinded, prospective trial. Lasers in surgery and medicine. 2016 Nov;     [PubMed PMID: 27426441]
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[21] Lee SJ,Kang JM,Chung WS,Kim YK,Kim HS, Ablative non-fractional lasers for atrophic facial acne scars: a new modality of erbium:YAG laser resurfacing in Asians. Lasers in medical science. 2014 Mar;     [PubMed PMID: 23793338]