Clinical and dermoscopic evaluation of combined (salicylic acid 20% and azelaic acid 20%) versus trichloroacetic acid 25% chemical peel in acne: an RCT

J Dermatolog Treat. 2019 Sep;30(6):572-577. doi: 10.1080/09546634.2018.1484876. Epub 2019 Mar 1.


Background: Combined azelaic acid (AA) and salicylic acid (SA) have not been previously used for acne. Objective: To compare the efficacy of this combination versus trichloroacetic acid (TCA) 25% peel in acne. Methods: Thirty-four patients were included in this trial. Patients received four sessions 2 weeks apart. The combined solution was applied to one side of the face, while TCA was applied to the other. Our outcomes were physician-reported clinical improvement, dermoscopic assessment of the erythema and patient's satisfaction. Results: After two sessions, a significant clinical improvement was observed in non-inflammatory lesions in the TCA-treated side-treated TCA and in inflammatory lesions in the SA/AA-treated side. At the end, both modalities led to significant improvement, with no significant difference in between. Patients reported more discomfort with the TCA-treated side. There was no significant different clinical improvement in both treated sides as regards SPT. Erythema improved in both sides. Patients were more satisfied by the SA/AA-treated side. Conclusion: Chemical peeling is effective in controlling mild-moderate acne in SPT III-IV. Combined SA 20% and AA 20% are recommended at early stage of treatment if patients have more inflammatory lesions, while TCA is recommended if patients have more non-inflammatory lesions.

Keywords: Acne; TCA; azelaic acid; dermoscopy; salicylic acid.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Acne Vulgaris / drug therapy*
  • Acne Vulgaris / pathology
  • Adolescent
  • Adult
  • Chemexfoliation
  • Dermoscopy
  • Dicarboxylic Acids / adverse effects
  • Dicarboxylic Acids / therapeutic use*
  • Erythema / drug therapy
  • Female
  • Humans
  • Male
  • Patient Satisfaction
  • Salicylic Acid / adverse effects
  • Salicylic Acid / therapeutic use*
  • Severity of Illness Index
  • Treatment Outcome
  • Trichloroacetic Acid / adverse effects
  • Trichloroacetic Acid / therapeutic use*
  • Young Adult


  • Dicarboxylic Acids
  • Trichloroacetic Acid
  • azelaic acid
  • Salicylic Acid