ORIGINAL ARTICLE The perilesional skin in vitiligo: a colorimetric in vivo study of 25 patients V. Brazzelli 1 , F. Muzio 1 , M. Antoninetti 1 , S. Villani 2 , F. Donadini 1 , A. Altomare 1 & G. Borroni 1 1 Department of Human and Hereditary Pathology, Institute of Dermatology, Fondazione IRCCS Policlinico S. Matteo, University of Pavia, Pavia, Italy, and 2 Department of Health Sciences, Section of Medical Statistics and Epidemiology, University of Pavia, Pavia, Italy Key words: colorimetry; non-invasive methods; perilesional skin; vitiligo Correspondence: Valeria Brazzelli, M.D., Clinica Dermatologica, Fondazione IRCCS Policlinico S. Matteo, Universita ` di Pavia, Piazzale Golgi 2, 27100 Pavia, Italy. Tel: 139 3 8250 3794 Fax: 139 3 8252 6379 e-mail: vbrazzelli@libero.it Accepted for publication: 16 May 2008 Conflicts of interest: None declared. Summary Background: The aim of this work was to study in vivo the perilesional skin in vitiligo with a colorimetric method. Methods: Twenty-five patients affected by vitiligo were included. For each patient, three different areas were considered: the lesional, the perilesional and the normal skin as far as 5 cm from the nearest vitiligo spot. Skin pigmentation measurements were performed with a chromameter. Results: The results showed that luminance L à decreased significantly in relation to increasing distance from the vitiligo spot. As expected, L à in the vitiligo spot was significantly higher than in the perilesional (P o 0.0001) and normal skin (P o 0.0001). There was a small difference in L à between normal skin as far as 5 cm from the nearest vitiligo spot and perilesional skin. In contrast, the pigmentation index (b à ) gradually increased from lesional to perilesional to normal skin. Furthermore, the comparison of the b à value between the normal skin as far as 5 cm from the nearest vitiligo spot was higher than perilesional skin and it was statistically significant (P o 0.0001). Conclusion: Our results in vivo underline that the perilesional skin near the vitiligo spot is lighter than normal skin as far as 5 cm from the vitiligo spot. V itiligo is a common acquired depigmenting disorder of the skin affecting approximately 1–2% of the world population, and in 50% of cases the condition begins before 20 years of age. It is characterized by circumscribed depigmented macules or patches, resulting from the loss of melanocytes from the epidermis (1). The etiology of vitiligo is as yet unknown and several hypotheses have been proposed for the loss of functioning melanocytes in the skin of these patients. One of the most longstanding and popular hypothesis considers vitiligo as an autoimmune disease (2–7). While the literature is replete with structural and morphological studies of depigmented patches of vitiligo, few reports focus on the normal-appearing perilesional skin near the depigmented skin even if several alterations of structure of melanocytes and keratinocytes have been described (8–14). However, it should be recognized that in addition to the above-described abnormalities, a number of biochemical changes have also been found in perilesional skin (15–17). Considering these observations and because the depigmentation process may be reversible, either spontaneously or by using various therapeutic approaches, we wished to re-examine in vivo the white/lesional skin, the ‘perilesional’ skin and the normal skin as far as 5 cm from the nearest white spot of patients with stable vitiligo by a non-invasive repetitive colorimetric method. Patients and methods Patients Twenty-five patients (13 males and 12 females), affected by stable generalized vitiligo, were included in the study. Their age ranged between 18 and 72 years (mean age 35.55  15.9 years). The mean duration of vitiligo ranged between 3 and 28 years (mean duration of vitiligo 10.61  8.56 years). Every patient was assessed for Fitzpatrick (18) skin phototype: 10 patients phototype II, 15 patients phototype III (Table 1). Every patient stopped any topical treatment or phototherapy irradiation since 1 month before the beginning of the study. For each patient, we considered three different areas: the lesional skin, the perilesional skin and the normal skin as far as 5 cm from the nearest vitiligo spot (Fig. 1). Furthermore, for each analyzed area we considered the mean value of three different sites in/or around the same lesion to obtain more homogeneous data. Informed consent was obtained from patients before starting the colorimetric measurements. Methods Skin pigmentation measurements were performed with a Minolta CR-200 chromameter (Minolta, Osaka, Japan). It is a portable r 2008 The Authors Journal compilation r 2008 Blackwell Munksgaard  Photodermatology, Photoimmunology & Photomedicine 24, 314–317 314