Effect of cold air cooling on the incidence of postinflammatory hyperpigmentation after Q-switched Nd:YAG laser treatment of acquired bilateral nevus of Ota like macules

Arch Dermatol. 2007 Sep;143(9):1139-43. doi: 10.1001/archderm.143.9.1139.


Objective: To investigate the effect of cold air cooling on the incidence of postinflammatory hyperpigmentation (PIH) after laser treatment in Asian patients.

Design: Randomized, controlled, split-face study.

Setting: Skin laser center of a university hospital.

Patients: Twenty-three Thai women with acquired bilateral nevus of Ota-like macules.

Interventions: Patients were treated using a 1064-nm Q-switched Nd:YAG laser at an average fluence of 7.0 J/cm(2) using a 3-mm spot size. The same laser fluence was used on both sides of the face in individual patients. One randomly selected face side of each patient was cooled using a cold air cooling device during and 30 seconds before and after laser irradiation, and the other side was irradiated without cooling.

Main outcome measures: Occurrence of PIH was objectively evaluated by measuring the melanin index using a spectrometer, and it was subjectively assessed by 2 nontreating physicians before treatment and once weekly for 4 weeks.

Results: Of the 21 patients who completed the study, 13 (62%) and 5 (24%) developed PIH on the cooled and uncooled sides, respectively. One patient (5%) had PIH on both the cooled and uncooled sides, and 2 (10%) did not experience PIH. The cooled sides were significantly more likely to become hyperpigmented after laser irradiation than the uncooled sides (relative risk, 2.6; 95% confidence interval, 1.13-6.00; P = .03). The clinical evaluation corresponded to the spectrometer reading.

Conclusion: Epidermal cooling with cold air is associated with an increased risk of PIH after Q-switched Nd:YAG laser treatment.

Trial registration: clinicaltrials.gov Identifier: NCT00287001.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Cold Temperature / adverse effects*
  • Facial Neoplasms / radiotherapy*
  • Female
  • Humans
  • Hyperpigmentation / etiology*
  • Low-Level Light Therapy / adverse effects*
  • Low-Level Light Therapy / methods
  • Middle Aged
  • Nevus of Ota / radiotherapy*
  • Skin Neoplasms / radiotherapy*

Associated data

  • ClinicalTrials.gov/NCT00287001