Ablative Non-fractional Lasers

The charts below show the chances of developing various side effects from ablative non-fractional lasers.^1-5 For some side effects, we currently do not have enough data to provide a percentage.

Certain/Likely Side Effects (% = Incidence)

*Skin redness (erythema): Skin redness is a typical reaction to ablative non-fractional laser treatment. After Er:YAG non-fractional laser treatment, skin redness lasts 1 month on average and normally disappears completely in 3 months. After CO2 non-fractional laser treatment, skin redness may last from 6 weeks to 3 months.^1,2,4

**Skin darkening (post-inflammatory hyperpigmentation): Skin darkening may occur in all skin types but is more common in patients with darker skin. It may begin 3-4 weeks after laser treatment and may persist for up to 3 months.¹

Possible/Rare Side Effects

*Prolonged skin redness (erythema): Prolonged skin redness is defined as redness that lasts over 3 months.^4,5

**Persistent skin darkening (hyperpigmentation): Persistent skin darkening is defined as skin darkening that lasts over 3 months.⁴

†Raised (keloid) scars: The likelihood of developing raised scars may depend on the specific laser settings. Patients with a history of keloid scarring are more likely to develop keloid scars as a side effect of ablative non-fractional laser treatment.

Studies:

Five studies have looked at the side effects of treatment with ablative non-fractional lasers.

• Study 1:
  
  
  • Authors: Alster et al.¹
  • Total # of patients: 50
  • # of female patients: 44
  • # of male patients: 6
  • Age of patients: 21-69
  • Laser type: CO₂ laser
  • Laser settings: 5-7 W, 500 mJ
  • Duration of treatment and follow-up: 1 treatment, follow-up at 1, 4, 8, 12, and 24 weeks
  • Side effects:
    
    • Erythema (redness): 100%
    • Hyperpigmentation (skin darkening): 36%
    • Milia (clogged sweat glands): 14%
    • Hypopigmentation (skin lightening): 6%

• Study 2:
  
  
  • Authors: Engin et al.²
  • Total # of patients: 21
  • # of female patients: (not reported)
  • # of male patients: (not reported)
  • Age of patients: 19-55
  • Laser type: Er:YAG laser
  • Laser settings: 7-mm spot size, 4 J/cm2 fluence, 350 msec pulse duration
  • Duration of treatment and follow-up: 1 treatment, follow-up for 3 months
  • Side effects:
    
    • Erythema (redness): 100%
    • Crusts: 100%
    • Acne flare-up: 9.5%
• Study 3:
  
  
  • Authors: Jeong et al.³
  • Total # of patients: 28
  • # of female patients: 17
  • # of male patients: 11
  • Age of patients: 19-38 Average: 26.9
  • Laser type: Long-pulsed Er: YAG laser
  • Laser settings: 7.0-7.5 J/cm2, 10 msec pulse duration
  • Duration of treatment and follow-up: 1 treatment, follow-up at 2 weeks, 1 and 3 months
  • Side effects:
    
    • Erythema (redness) after the treatment: 100%
    • Prolonged erythema (redness) which lasted for more than 3 months: 54%
    • Itching sensation: 54%
    • Post-inflammatory hyperpigmentation (skin darkening): 29%
    • Acne flare-up: 29%
    • Hypopigmentation (skin lightening): 4%
• Study 4:
  
  
  • Authors: Lee et al.⁴
  • Total # of patients: 22
  • # of female patients: 17
  • # of male patients: 5
  • Age of patients: 25-44 Average: 30
  • Laser type: Er:YAG laser
  • Laser settings: 17.5 J/cm2 with 50 % spot overlap (spot size of 4 mm) and 70 μm of coagulation
  • Duration of treatment and follow-up: 1 treatment, follow-up for 6 months
  • Side effects:
    
    • Erythema (redness) after the treatement: 100%
    • Post-inflammatory hyperpigmentation (skin darkening): 45.5%
    • Acne flare-up: 22.7%
    • Prolonged erythema (redness) which lasted for more than 3 months: 9.1%
    • Prolonged post-inflammatory hyperpigmentation (skin darkening) which laster for more than 3 months: 4.5%
    • Hypopigmentation (skin lightening): 4.5%
• Study 5:
  
  
  • Authors: Tanzi et al.⁵
  • Total # of patients: 25
  • # of female patients: 23
  • # of male patients: 2
  • Age of patients: 21-65 Average: 42.3
  • Laser type: Er:YAG laser
  • Laser settings: 22.5 J/cm² with 50% overlap and 50 μm of coagulation
  • Duration of treatment and follow-up: 1 treatment, follow-up for 12 months
  • Side effects:
    
    • Post-inflammatory hyperpigmentation (skin darkening): 44%
    • Acne flare-up: 32%
    • Infection: 20%
    • Milia (clogged sweat glands): 12%
    • Dermatitis: 8%
    • Prolonged erythema (redness) which lasted for more than 3 months: 4%

Study 1: In a study published in 1996 in the journal Dermatologic Surgery, Alster and colleagues treated 50 patients with moderate to severe atrophic (indented) acne scars with CO₂ non-fractional laser. Patients received one laser treatment with ablative non-fractional laser and were followed up at 1, 4, 8, 12, and 24 weeks after the treatment. Side effects were mild and included redness after the treatment, skin darkening of lightening, as well as the development of white bumps (cysts) under the surface of skin (milia).¹

Study 2: In a study published in 2012 in The Journal of Dermatology, Engin and colleagues treated 21 patients with moderate to severe atrophic (indented) acne scars with Er:YAG laser. Patients received one laser treatment with ablative non-fractional laser and were followed up for 3 months after the treatment. All patients experienced erythema (redness) after the treatment and developed crusts which resolved within 9 days. In 9.5% of patients exacerbation of the active acne lesions was observed. These patients were prescribed topical benzoyl peroxide gel and their condition improved within 1 month.²

Study 3: In a study published in 2001 in the journal Dermatologic Surgery, Jeong and colleagues treated 28 patients with atrophic (indented) acne scars with long-pulsed Er: YAG laser. Patients received one laser treatment and were followed up at 2 weeks, 1 month, and 3 months after the treatment. While all patients experienced erythema (redness) after the treatment in 54% of patients, redness lasted for more than 3 months. More than half (54%) also experienced an itching sensation, while an acne flare-up happened in 29%. The authors also reported post-inflammatory hyperpigmentation (skin darkening) and hypopigmentation (skin lightening) as common side effects of ablative non-fractional laser treatment.³

Study 4: In a study published in 2013 in the journal Lasers in Medical Science, Lee and colleagues treated 22 patients with atrophic (indented) acne scars with Er:YAG laser. Patients received one laser treatment and were followed up for 6 months. As expected, erythema (redness) after the treatment was the most commonly reported side effect, followed by post-inflammatory hyperpigmentation (skin darkening), and acne flare-up. It’s worth noting that extended redness and skin darkening also occurred, albeit in significantly fewer instances.⁴

Study 5: In a study published in 2002 in the journal Dermatologic Surgery, Tanzi and colleagues treated 25 patients with atrophic (indented) acne scars with Er:YAG ablative, non-fractional laser. Patients received one laser treatment and were followed up for a year. Authors reported side effects such as skin darkening and acne flare-up, but also the development of superficial infections and dermatitis. All side effects resolved within a year.⁵