Effective Treatment for Post-inflammatory Hyperpigmentation Caused by Cosmetic Procedures / 대한피부과학회지

BACKGROUND: Postinflammatory hyperpigmentation (PIH) is one of the most common adverse effects associated with dermatologic procedures, especially those for cosmetic purposes. Low fluence Q-Switched Nd:YAG laser (LFQS) has been widely used for this condition in the field, but reports in the literature are scarce. OBJECTIVE: We aimed to evaluate the clinical benefit and limitation of LFQS in the treatment of PIH after cosmetic procedures. METHODS: Patients with PIH after laser treatment were enrolled in the study. Patients were treated with LFQS at an interval of 2 to 3 weeks. Photographs were taken. Objective measurement included erythema and melanin indices at the same site. Two blinded assessors graded the degree of improvement using a photograph based on a quartile scale (0~3). Patient satisfaction after treatment was also reported. RESULTS: A total of 45 patients were included in the analysis. Patients received 10 treatment sessions. Patients who started LFQS treatment within 3 months after the causal event showed a better treatment outcome. Those who had a higher erythema index before treatment tended to respond less to the treatment. CONCLUSION: LFQS may be a good treatment modality for patients with PIH. Earlier treatment can provide rapid resolution and better clinical results. However, for patients with PIH combined with intense erythema, LFQS may not be the first choice to consider in the clinical field.

Treatment of Melasma and Post-Inflammatory Hyperpigmentation by a Picosecond 755-nm Alexandrite Laser in Asian Patients

The picosecond lasers have shown to effectively treat tattoo pigments that are intractable to previous multiple Q-switched (QS) laser treatments. Therefore we hypothesized that a picosecond laser would show better efficacy with minimal adverse events in the treatment of melasma and post-inflammatory hyperpigmentation (PIH) that are difficult to treat with conventional QS lasers. Two patients with melasma and one patient with PIH were treated with a Picosecond 755-nm Alexandrite Laser (Cyanosure, USA). All patients were Korean with skin type IV and no longer responding to QS laser treatments. Laser treatment was well tolerated in all the patients. Adverse events such as PIH were not reported during 8 weeks of follow up period. After the multiple treatment sessions, one patient reported fair improvement and two patients reported good improvement. Consistent with the clinical results, ex vivo skin model irradiated with a Picosecond 755-nm Alexandrite Laser also showed decreased epidermal keratinocyte necrosis compared with the 532-nm QS Neodymium-Doped Yttrium Aluminium Garnet Laser (Lutronic, Korea) yet decreased melanin content. In conclusion, the Picosecond 755-nm Alexandrite Laser may be useful for effective treatment of intractable melasma and PIH with fewer adverse events in dark Asian skin.