Axillary hyperpigmentation is a frequent dermatological complaint, characterized by dermal and epidermal PIH mainly associated with women of darker skin types. Etiological theory associates axillary hyperpigmentation of a form of post inflammatory hyperpigmentation due to continuous irritation due to hair removal, cleansing, tight cloths, or innate darkening from genetic related factors.11 The purpose of this case study was to evaluate the efficacy of a 1064nm nanosecond QS Nd:YAG laser in the treatment of axillary PIH in Filipino women with Fitzpatrick skin types IV-V.
MATERIALS AND METHODS
Nine (9) female patients, aged 20 to 52 years (mean age 39 ± 10 years), with skin types IV-V and bi-lateral underarm hyperpigmentation (18 axillae) were included in this prospective study. Verbal and written informed consent were obtained. The patients were in good health and were not treated with concomitant whitening or depigmenting agents.
All 18 axillae were treated with a QS Nd:YAG (1064nm) laser (Alma Q, Alma Lasers GmbH, Nürnberg, Germany). Treatment was carried out according to the following treatment protocol: four (4) passes over the treatment area with a focused handpiece, 7 mm spot size, fluence of 2.6mJ/cm2 until total energy accumulation reached 800 kJ. Case study design included a 10-week treatment protocol, which consisted of 4 treatment sessions at 2 weeks intervals and a follow-up visit at one and three months following the fourth treatment.
Primary end point of the study was reduction in axillary hyperpigmentation. Pigmentary changes were assessed by calculating the L* (luminosity) according to the Von Luschan's Chromatic classification scale (Figure 1). Improvement was assessed by comparing the difference (L*Δ) between target treatment area of the axilla and a non PIH affected area (L*Δ= axilla–periaxilla), at baseline and at the final follow-up visits. Assessment was carried out by the treating physician and by two other objective evaluators. Clinical improvement was assessed by the GIAS score (stages of improvement scoring: 1= very much improved, 2= much improved, 3= improved, 4= no change, or 5= worse outcomes) both by the treating physician and the patients throughout the study. Safety parameters included treatment related adverse events and pain, scored on a 10-point visual assessment scale (VAS scale), recorded after each treatment.