A pilot methodology study for the photographic assessment of post-inflammatory hyperpigmentation in patients treated with tretinoin.

BACKGROUND

Post-inflammatory hyperpigmentation (PIH) is a common occurrence in patients with acne vulgaris, particularly in those with skin of colour.

AIMS: A previous study has demonstrated the benefit of tretinoin (retinoic acid) in the treatment of PIH; however, there is currently no standard protocol to evaluate change in PIH following treatment. Based on these findings, we performed a pilot, exploratory, blinded, intraindividual-controlled methodology study that consisted of a photographic assessment protocol with facial mapping.

MATERIALS AND

METHODS

The study was based on a secondary analysis of a phase 4, community-based trial of 544 acne patients who were treated with tretinoin gel microsphere 0.04% or 0.1%. Only patients with Fitzpatrick types III-V (skin of colour) were included in the study; subjects with Fitzpatrick skin type VI were excluded because the photographic assessment did not allow for proper evaluation.

RESULTS

Despite the small number of subjects evaluated (n=25), the results revealed consistent assessment of improvement in PIH between two independent graders (weighted κ=0.84).

CONCLUSION

Further study with a larger population is recommended to validate the accuracy of this method.