Ashy dermatosis with prior pruritic and scaling skin lesions

group 2 were low, as was expected, repigmentation wasobserved in 76% of the lesions after 40 treatment sessionsand one patient showed a relatively high repigmentation scoreof 3. Repigmentation scores in group 1 increased significantlybetween 30 and 50 sessions (Wilcoxon rank sum test,P = 0.002). Similarly, repigmentation scores in group 2increased significantly between 30 sessions and 50 sessions(Wilcoxon rank sum test, P = 0.045). These findings indicatethat additional repigmentation occurred, even if repigmentationappeared to reach a plateau at approximately 30 sessions.In group 1, normal MED correlated significantly with therepigmentation score (Pearson correlation coefficient test,P < 0.05; n = 60), possibly because patients with high MEDvalues would be high responders (well pigmented by excimerlaser).The L* and a* values of the vitiligo lesions before lasertreatment were significantly different from those after lasertreatment (P < 0.0001; Fig. 2). The repigmentation scores ofgroup 1 correlated significantly with the vitiligo a* values (aftertreatment; Pearson correlation coefficient test, ρ = !0.72;P < 0.05; n = 12). Repigmentation scores were inversely corre-lated with erythema of post-treatment vitiligo, suggesting thatintense erythema responses could not be ideal for better repig-mentation.In conclusion, continuing excimer laser therapy beyond 30sessions may be worthwhile for patients with incurable vitiligo.Further, factors that contribute to a favorable response to the308-nm excimer laser include the site of the vitiligo lesions, aswell as the MED and a* values, which indicate the redness ofthe vitiligo patch.