Postinflammatory hyperpigmentation (PIH) is a common consequence following cutaneous inflammation in darkskinned individuals with Fitzpatrick skin phototypes (SPTs) III-VI. The exact pathogenesis of this condition is unknown, but is believed to be an integral part of the normal response of the skin to inflammatory stimuli. PIH can last from months to years and may significantly impair quality of life of affected individuals. The primary treatment of PIH is prevention and treatment of the underlying inflammatory condition. In addition to prevention, there are a variety of medication and procedures used to treat PIH. Although topical skin-depigmenting agents remain the treatment of choice for PIH, lasers and light sources may be an effective adjunctive therapy or alternative for treatment failures. When treating PIH, any treatment options selected should be optimized and utilized carefully because the treatments itself may worsen the PIH.

Background and Objective Phototherapy for acne with a combination of blue and red light‐emitting diodes (LEDs) appears to have excellent potential in treating inflammatory acne. However, a standard twice‐weekly protocol administered 3 days apart may not be practical for patients. This study aims to seek the efficacy of LED treatment in moderate to severe acne, comparing between once and alternating twice‐weekly regimens. Study Design/Materials and Methods Thirty subjects with moderate to severe acne, as defined by Burton's grading score, were recruited in the study. The subjects were randomly divided into two groups‐ one group received alternating blue (470 nm) and red (640 nm) light in two visits per week for 4 consecutive weeks, while the other group got blue and red light treatments consecutively on the same visit for 4 consecutive weeks. During the study period, conventional treatments were prohibited. Clinical assessments were performed by lesion counts and blinded comparative photographs before treatment and at 1, 4, and 8 weeks after the final treatment. Results There was no statistically significant difference between once‐ and alternating twice‐weekly regimens. Both regimens provided marked improvement only for inflammatory lesions. The median percentage of acne reduction was significantly demonstrated for 1 week after finishing the course of treatment and was sustained until the end of the study. There were no side effects noted throughout the study period. Conclusion LED therapy is safe and effective for treatment of inflammatory acne. The treatment outcomes of once and alternating twice‐weekly regimens were comparable, hence, once‐weekly treatment could be considered as an alternative choice for patient's convenience. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.