RESULTS
Reduction in hyperpigmentation of the axillae was apparent in all patients, affecting 85-100% of pigmented lesion. At the one-month follow-up visit, the mean L*Δ values were 0.4±0.05 compared to 3.5±1.58 at baseline, presenting major pigmentary improvement following laser treatment (Table 1). At the three months follow-up visit, all patients maintained their improved state in PIH reduction. Clinical improvement by GIAS scores rated laser treatment for axillary PIH by the physician and the patients as excellent in 33.3% and 22.2%, very much improved in 55.5% (by both physician and patients), and improved in 22.2% and 11%, respectively (Table 2).
The VAS pain rating was scored after each treatment and reported as 3.8, 2.7, 1.4, and 1, respectively. No adverse events were reported during the trial or at the follow-up visits.
The VAS pain rating was scored after each treatment and reported as 3.8, 2.7, 1.4, and 1, respectively. No adverse events were reported during the trial or at the follow-up visits.
DISCUSSION
Post inflammatory hyperpigmentation (PIH) is a common acquired pigmentary disorder. Melanocytes of darker skin types are hyperactive and thus release more melanin, which may account for the high frequency of PIH in Fitzpatrick skin types IV-VI populations.2 Recently, laser-based treatments have emerged as safe and effective therapeutic options for PIH, specifically targeting melanin. The Q-Switched photoacoustic effect promotes chromophore shattering with subsequent evacuation by immunologic associated cells. These treatments have produced variable results when treating PIH.
Near-infrared lasers such as 1064nm QS Nd:YAG laser are less absorbed by melanin compared with the green and red light lasers thus are considered safer for the treatment of patient with darker skin types. This is due to the fact that the 1064nm wavelength targets not only melanin but also hemoglobin and water. In addition, the 1064nm wavelength is known for its deeper penetration into the skin and thus can effectively target dermal pigmented lesions.8,12 A study using low-fluence 1064nm QS Nd:YAG laser was shown to be a safe and effective treatment for PIH as a single or combined therapy, however, with recurrence after several weeks.7 To date there are limited studies on the 1064nm QS Nd:YAG laser for PIH treatment, with most clinical data collected from melasma studies.12
Recently, the efficacy of low-fluence 1064nm- QS Nd:YAG laser was evaluated for the treatment of the axillary hyperpigmentation with satisfactory results. This was the first observational study clinically testing axillary PIH treatment using laser, which exhibited good-to-excellent improvement after a minimum of 3 treatments with lasting results for at least 6 months.4 Our study followed a similar treatment protocol and laser to be done on Filipino women with skin types IV-V.
Near-infrared lasers such as 1064nm QS Nd:YAG laser are less absorbed by melanin compared with the green and red light lasers thus are considered safer for the treatment of patient with darker skin types. This is due to the fact that the 1064nm wavelength targets not only melanin but also hemoglobin and water. In addition, the 1064nm wavelength is known for its deeper penetration into the skin and thus can effectively target dermal pigmented lesions.8,12 A study using low-fluence 1064nm QS Nd:YAG laser was shown to be a safe and effective treatment for PIH as a single or combined therapy, however, with recurrence after several weeks.7 To date there are limited studies on the 1064nm QS Nd:YAG laser for PIH treatment, with most clinical data collected from melasma studies.12
Recently, the efficacy of low-fluence 1064nm- QS Nd:YAG laser was evaluated for the treatment of the axillary hyperpigmentation with satisfactory results. This was the first observational study clinically testing axillary PIH treatment using laser, which exhibited good-to-excellent improvement after a minimum of 3 treatments with lasting results for at least 6 months.4 Our study followed a similar treatment protocol and laser to be done on Filipino women with skin types IV-V.
