BACKGROUND: Progressive macular hypomelanosis (PMH) is a skin disorder characterized by multiple hypopigmented patches symmetrically distributed on the trunk. Several treatment modalities have been attempted; however, a standard treatment modality has not been agreed to.
OBJECTIVES: The aim of this study was to compare the effectiveness of antimicrobial therapy combined with narrow band ultraviolet B (NBUVB) with NBUVB monotherapy.
METHODS: A randomized left-right comparison study was conducted in a total of 10 patients. Patients received NBUVB therapy with daily application of antimicrobial gel on one side of the trunk (comb-NBUVB) and without it (mono-NBUVB) for 8 weeks. The clinical efficacy was determined by objective measurements using a colour analyser and subjective assessment by evaluating pictures taken with a digital camera at baseline, at the time of treatment cessation and 6 months after treatment.
RESULTS: Significant repigmentation was observed in all 10 patients during the 8 weeks of treatment. The mean difference in L values between lesional and non-lesional skin was reduced in the comb-NBUVB area (from 4.52 ± 1.65 to 0.94 ± 0.65), and in the mono-NBUVB area, (from 4.34 ± 1.39 to 1.18 ± 0.94). There was no significant difference between treated sites at both of the evaluation points in time. At 6 months after treatment, 7 of 10 patients completed the clinical trial, and some degree of clinical improvement remained in four of seven patients; recurrence occurred in the other patients.
CONCLUSIONS: Although recurrence occurred in some patients, NBUVB treatment appears to be a safe and useful modality for the treatment of PMH.