CROSS Technique (TCA Cross)

The charts below show the chances of developing various side effects from the CROSS technique.^4-10

Certain/Likely Side Effects (% = Incidence)

*Transient skin darkening (hyperpigmentation) lasting less than 7 days, itching: These percentages are based on clinical studies. Study patients often do not report transient skin darkening and itching as side effects, because these are normal and expected skin reactions to the CROSS technique. The actual percentages of people who experience transient skin darkening and itching after the CROSS technique are likely higher.

Possible/Rare Side Effects

Studies:   

Seven studies have looked at the side effects of treatment with the CROSS technique.

• Study 1:
  
  
  • Authors: Bhardwaj and Khunger⁴
  • Total # of patients: 12
  • # of female patients: 10
  • # of male patients: 2
  • Age of patients: 14-42
  • Chemical used: 100% TCA
  • Duration of treatment and follow-up: 4 treatments, follow-up for 6 months
  • Side effects: Transient hyperpigmentation (skin darkening) lasting less than 7 days: 8.3%
    
• Study 2:
  
  
  • Authors: Agarwal et al.⁵
  • Total # of patients: 53
  • # of female patients: 120
  • # of male patients: 33
  • Age of patients: Average: 21.7
  • Chemical used: 70% TCA
  • Duration of treatment and follow-up: 4 treatments, follow-up at 3 months
  • Side effects: Post-inflammatory hyperpigmentation (skin darkening): 34%
    
• Study 3:
  
  
  • Authors: Ahmed et al.⁶
  • Total # of patients: 14
  • # of female patients: (not reported)
  • # of male patients: (not reported)
  • Age of patients: Average: 22.7
  • Chemical used: 100% TCA
  • Duration of treatment and follow-up: 4 treatments, follow-up at 3 months
  • Side effects:
    • Temporary hypopigmentation (skin lightening): 64.2%
    • Infection: 42.8%
    • Itching: 7.1%
      
• Study 4:
  
  
  • Authors: Khunger et al.⁷
  • Total # of patients: 30
  • # of female patients: 20
  • # of male patients: 10
  • Age of patients: 17-42 Average: 25
  • Chemical used: 100% TCA
  • Duration of treatment and follow-up: 4 treatments, follow-up at 3 months
  • Side effects:
    • Transient post-inflammatory hyperpigmentation (skin darkening): 6.7%
    • Transient post-inflammatory hypopigmentation (skin lightening): 3.4%
      
• Study 5:
  
  
  • Authors: Nofal et al.⁸
  • Total # of patients: 15
  • # of female patients: (not reported)
  • # of male patients: (not reported)
  • Age of patients: Average: 25
  • Chemical used: 100% TCA
  • Duration of treatment and follow-up: 3 treatments, follow-up at 2 weeks
  • Side effects:
    • Hyperpigmentation (skin darkening): 26.7%
    • Pain: 100%
      
• Study 6:
  
  
  • Authors: Dalpizzol et al.⁹
  • Total # of patients: 15
  • # of female patients: 12
  • # of male patients: 3
  • Age of patients: 18-52 Average: 28.5
  • Chemical used: 88% phenol
    • Duration of treatment and follow-up: 4 treatments, follow-up at 1 month
    • Side effects:
      • Persistent erythema (redness): 28.4%
      • Hyperpigmentation (skin darkening): 14.3%
      • Hypochromia (decreased hemoglobin in red blood cells): 14.3%
      • Increased scar width: 14.3%
      • Hypochromia (decreased hemoglobin in red blood cells): 0%
      • Increased scar width: 0%
  • Chemical used: 90% TCA
    • Duration of treatment and follow-up: 4 treatments, follow-up at 1 month
    • Side effects:
      • Persistent erythema (redness): 14.5%
      • Hyperpigmentation (skin darkening): 14.3%
      • Hypochromia (decreased hemoglobin in red blood cells): 14.3%
      • Increased scar width: 14.3%
• Study 7:
  
  
  • Authors: Ramadan et al.¹⁰
  • Total # of patients: 20
  • # of female patients: 14
  • # of male patients: 6
  • Age of patients: 20-52 Average: 27.6
  • Chemical used: 100% TCA
  • Duration of treatment and follow-up: 1-3 treatments, follow-up for up to 10 months
  • Side effects:
    • Residual erythema (redness): 25%
    • Hyperpigmentation (skin darkening): 15%
    • Hypopigmentation (skin lightening): 10%

Study 1: In a study published in 2010 in the Journal of Cutaneous and Aesthetic Surgery, Bhardwaj and Khunger treated 12 patients with predominantly icepick acne scars with the CROSS technique. The researchers gave the patients 4 treatments with 100% TCA at intervals of 2 weeks and followed up with the patients for 6 months. No major side effects were observed. Individuals with darker skin did not experience any significant complications. One patient experienced transient hypopigmentation (skin lightening) that lasted 7 days.⁴

Study 2: In a study published in 2015 in the journal Dermatologic Surgery, Agarwal and colleagues treated 35 patients with post-acne atrophic (indented) scars with the CROSS technique. The patients were treated with 70% TCA every 2 weeks for a total of 4 sessions and were followed up for 3 months. Eighteen patients developed post-inflammatory hyperpigmentation (skin darkening) of the treated areas at some point during treatment and/or follow-up. None of the patients experienced persistent erythema (skin redness), keloid (raised) scars, or any other serious adverse effects.⁵

Study 3: In a study published in 2014 in the Journal of Cosmetic and Laser Therapy, Ahmed and colleagues treated 14 patients with the CROSS technique. The patients were treated with 100% TCA for 4 sessions at 3-week intervals and were followed up at 3 months. All the patients experienced side effects.⁶

• In a study published in 2011 in the Journal of Cosmetic Dermatology, Khunger and colleagues treated 30 patients with icepick scars with the CROSS technique. The patients received 4 treatments with 100% TCA at intervals of 2 weeks and were followed up at 3 months. Two patients experienced transient post-inflammatory hyperpigmentation (skin darkening) that lasted one week. One patient developed transient post-inflammatory hypopigmentation (skin lightening) that improved in 6 days. None of the patients experienced serious side effects such as scarring or persistent changes in skin coloring.⁷

• In a study published in 2014 in the journal Dermatologic Surgery, Nofal and colleagues treated 15 patients with atrophic (indented) acne scars with the CROSS technique. The patients received 3 treatments with 100% TCA at 2-week intervals and were followed up 2 weeks after the last treatment. No major side effects were reported by the patients.⁸

• In a study published in 2016 in Dermatologic Surgery, Dalpizzol and colleagues treated 15 patients with icepick and boxcar acne scars with the CROSS technique. The patients were treated with 88% phenol on the left side of the face and 90% TCA on the right side of the face for 4 sessions at 3-week intervals and were followed up 1 month after the last treatment. Two patients developed hypochromia (decreased hemoglobin in red blood cells) and two patients’ scars became wider on the side of the face that was treated with 90% TCA.⁹

• In a study published in 2011 in Dermatologic Surgery, Ramadan and colleagues treated 20 patients with rolling scars with the CROSS technique on the left side of the face. The patients received 1-3 treatments with 100% TCA and were followed up to 10 months. Five patients experienced residual erythema (skin redness), three developed hyperpigmentation (skin darkening), and two showed mild hypopigmentation (skin lightening) after treatment.¹⁰