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.

Analysis of symmetricity in the three different (sagittal, transverse and frontal) planes in generalized nonsegmental vitiligo.

BACKGROUND: Nonsegmental vitiligo is defined as being "often symmetrical", however, no work has tackled the point as to how valid it is to depend upon the concept of symmetricity in generalized nonsegmental vitiligo. AIMS: To investigate vitiligo symmetry, taking into account sites of predilection, the clinical characteristics of patients were studied. METHODS: This multicentric study included 712 nonsegmental vitiligo patients with 2876 examined lesions. Three models were drawn for each patient. Sagittal, transverse and frontal planes were drawn to divide the body into right/left, upper/lower and anterior/posterior halves respectively. Patients were examined by Wood's light and analyzed for symmetry. RESULTS: Bilateral involvement was present in 78% (P < 0.001). Studying the similarity of clinical involvement in the upper and lower body parts revealed that such similarity was present in 38%, with a significant positive association in some areas. Studying clinical similarity in the anteroposterior distribution pattern revealed a significant positive association in 11%. LIMITATIONS: Relatively low number of patients. CONCLUSIONS: We found significant bilateral symmetry in the lesions of 78% of vitiligo patients. Our work could aid in drawing the anticipated vitiligo map in patients with active disease, helping in increasing our understanding of the clinical behaviour of this disease.

Evaluation of different factors influencing objective measurement of skin color by colorimetry.

BACKGROUND: Objective determination of skin color has become an essential requirement in managing pigmentary disorders including vitiligo. The readings of available devices can be influenced by factors such as surrounding temperature, vasodilation/constriction, and skin surface properties. Our aim was to investigate the influence of hair color and length, skin stretching, incomplete contact of the device with the skin, and the pressure with which the device is applied to the test area on skin color determination. MATERIALS AND METHODS: Dermacatch® was used to determine the influence of hair color and length in 30 vitiligo patients, and of wrinkles, incomplete contact of the device with the skin and pressure of the device on the test area in 30 healthy volunteers on melanin and erythema indices measured by the device. RESULTS: Melanin index was significantly higher in lesions with black hair compared to lesions with white hair (P < 0.001) and the MI significantly decreased when the black hair was shaved (P < 0.001) and when the skin over the test area was stretched (P < 0.001). Incomplete contact of the device with the test area led to significantly higher MI (P < 0.001) and lower EI (P < 0.001). Meanwhile, high pressure induced by the device on the test area led to significantly lower MI (P < 0.001) and significantly higher EI (P < 0.001). CONCLUSIONS: Factors influencing the readings of devices used for objective determination of skin color have to be taken consideration to ensure accuracy of the measurements done.