Quantitative method for measuring therapeutic efficacy of the 308 nm excimer laser for vitiligo

Assessment of changes in color and size of vitiligo lesions during treatment with narrow band ultraviolet B

BACKGROUND

Many treatment modalities have been used to stabilize vitiligo and induce repigmentation. Several methods were used to monitor the color changes inside the treated lesions such as spectroscopes and colorimeters that measure the melanin index inside the lesion.

OBJECTIVE

To study whether the colorimeter and point counting technique can be used as objective methods in monitoring vitiligo lesions during treatment with Nb-UVB.

METHODS

Twenty randomly chosen patients with non-segmental vitiligo were enrolled in this interventional study. Vitiligo disease activity score was recorded in each patient. Patients received Nb-UVB three times per week for 6 months. Two lesions were chosen in each patient, and each lesion was assessed for size using point counting technique and degree of color using the Dermacatch® at the beginning of the treatment and evaluated for changes in color and size every 4 weeks till the end of the treatment.

RESULTS

After 6 months of treatment, regarding the lesion size, 90% of lesions showed variable degrees of repigmentation and 10% showed increase in size, indicating increased activity of the disease, and regarding to color changes. We noticed that after one month of Nb-UVB treatment, there is marked increase in MI measurements in many lesions before any clinical improvement appeared, while at the end of treatment, inside the lesion; 95% showed an increase in melanin index and 5% showed no elevation. While the color changes outside the lesion showed 75% of lesions increased in melanin index, 15% remained unchanged and 10% of the lesions showed decrease in melanin index.

CONCLUSION

Colorimeter was able to detect change in color after only one month of treatment before it was clinically apparent which means that it can be used as a prognostic tool.

Utility of dermoscopy for evaluating the therapeutic efficacy of tacrolimus ointment plus 308-nm excimer laser combination therapy in localized vitiligo patients

The aim of the present study was to assess the function of dermoscopy in evaluating the therapeutic efficacy of tacrolimus ointment plus 308-nm excimer laser combination therapy in patients with localized vitiligo. A total of 147 patients with localized vitiligo (progressive disease, n=92; stable period, n=55) were enrolled and received combination therapy for 12 weeks. The condition of the skin lesions was monitored by dermoscopy and visual observation. At the initial visit, skin lesions were observed in 61 progressive and 19 stable patients. Residual perifollicular pigmentation was more abundant in progressive-stage patients than in stable-stage patients, whereas the presence of perilesional hyperpigmentation was obviously lower in patients with progressive vitiligo. After 12 weeks of combination therapy, marked differences in residual perifollicular pigmentation were identified between the progressive- and stable-stage patients. Dermoscopy and visual observation indicated that the 12-week treatment efficacy in patients with progressive disease was significantly higher than in those with stable disease and that assessment by dermoscopy was superior to visual observation at 8 or 12 weeks of treatment. Binary logistic regression analysis revealed that the disease stage, vitiliginous areas and disease course were risk factors associated with the treatment efficacy of the combination therapy. In conclusion, dermoscopy may be used as an effective means of vitiligo therapy assessment to provide an accurate and scientific evaluation of treatment efficacy for localized vitiligo patients.