Videodermoscopic Changes of the Hair in Vitiligo Lesions in Relation to Disease Duration.

Introduction: Vitiligo is an acquired disease of complex pathogenesis, in which the immunologic attack to the skin and hair follicle melanocytes leads to areas of depigmentation and leukotrichia, respectively. Objectives: To study the dermoscopic features of the hair changes in vitiligo lesions in comparison to perilesional control areas and in relation to disease duration. Methods: Forty-seven patients with both old and recent vitiligo lesions were included. Dermoscopic features of hair within the lesions were examined and compared to those in perilesional non depigmented skin of the same patient. Results: Hair density (P < 0.001), terminal hair rate (P = 0.011), terminal to vellus hair ratio (P = 0.029) and mean hair shaft thickness (P = 0.031) were significantly decreased, whereas vellus hair rate (P = 0.011) was significantly increased in old vitiligo lesions compared to their respective control areas. The frequency of broken hair was significantly higher in old lesions (P < 0.001), while that of upright re-growing hair was significantly higher in recent lesions (P = 0.016). Conclusions: Hair involvement in vitiligo lesions is not only limited to the development of leukotrichia. Other subtle changes in hair density, anagen and telogen hair rates, and mean hair thickness can be detected. These changes may serve as objective clues to the duration of the lesions.

Value of silicone gel in prevention of cobblestoning following punch minigrafting in vitiligo.

BACKGROUND: Cobblestoning is the most common complication of minipunch grafting. OBJECTIVE: To assess the value of silicone gel application following minipunch grafting and the histopathological and immunohistochemical changes in cases with cobblestoning. METHODS: Minipunch grafting was performed in two similar vitiligo lesions in 27 cases with stable vitiligo. After healing, silicone gel was applied twice daily on one lesion while zinc oxide ointment was applied to the other lesion serving as a control. Four biopsies were taken from each case; normal, vitiliginous skin before treatment and the two treated lesions 3 months after therapy, for histopathology and immunohistochemical staining for MMP9 & tenascin-C. RESULTS: Repigmentation occurred in 19 cases (70.7%). The number of lesions showing excellent and good response was significantly higher on the silicone gel side (p < .001). In 20 cases, cobblestoning either occurred or was absent on both sides. Histopathologically, cobblestoning was similar to hypertrophic scarring. Both markers were elevated after therapy on both sides with no significant difference in percentage change between lesions showing positive and negative cobblestoning. CONCLUSION: Silicone gel application after minigrating improved the final response with no significant effect on the occurrence of cobblestoning. Cobblestoning resembled hypertrophic scarring histopathologically.

The use of intralesional corticosteroid combined with narrowband ultraviolet B in vitiligo treatment: clinical, histopathologic, and histometric evaluation.

BACKGROUND: Treatment of vitiligo with intralesional steroid (ILS) injections has shown to be successful in quite a few studies. It is a simple and safe treatment when used with caution with a better response in localized lesions. OBJECTIVES: The aim of the present study is to explore the efficacy and safety of using different concentrations of intralesional corticosteroid combined with NB-UVB phototherapy in the treatment of non-segmental vitiligo (NSV) patients. METHODOLOGY: Twenty patients with non-segmental vitiligo were subjected to different concentrations of ILS injections (triamcinolone acetonide); that was carried out monthly for six sessions. All patients were also subjected to twice-weekly sessions of NB-UVB for 6 months. Punch biopsy was taken from each patch before and at the end of treatment sessions. Each biopsy was stained with hematoxylin and eosin (H&E), Orcein, and Masson's trichrome stains. RESULTS: There was a significant difference between all groups in their repigmentation response (P = 0.017). After treatment, the epidermal thickness (histometry) was decreased (epidermal atrophy), especially with concentrations of 2.5 and 5 mg/ml of intralesional triamcinolone acetonide injection with decreased and disorganized collagen fibers. CONCLUSION: Intralesional corticosteroid injections combined with NB-UVB showed a good and well-tolerated therapeutic option for vitiligo. The concentrations of 0.625 and 1.25 mg/ml of triamcinolone acetonide were the safest with fewer side effects and complications. However, higher concentrations of 2.5 and 5 mg/ml were more effective but with more side effects.

Efficacy of narrow band UVB with or without OMP in stabilization of vitiligo activity in skin photo-types (III-V): A double-blind, randomized, placebo-controlled, prospective, multicenter study.

BACKGROUND: NB-UVB has long been the vitiligo management pillar with capability of achieving the main treatment outcomes; repigmentation and stabilization. Its stabilizing effect in dark skin has been debatable. However, randomized controlled trials regarding NB-UVB ability to control disease activity are lacking. PURPOSE: To assess stabilizing effect of NB-UVB in comparison to systemic corticosteroids, the mainstay in vitiligo stabilization, in skin photo-types (III-V). METHODS: This is a multicenter, placebo-controlled, randomized, prospective study. Eighty patients with active nonsegmental vitiligo (NSV) (Vitiligo disease activity (VIDA) ≥2) were randomized to either NB-UVB and placebo (NB-placebo) or NB-UVB and dexamethasone oral mini-pulse (OMP) therapy (NB-OMP) for 6 months. Sixty four patients completed the study, 34 in the NB-OMP group and 30 in the NB-placebo group. Patients were evaluated fortnightly according to presence or absence of symptoms/signs of activity. RESULTS: In spite of earlier control of disease activity observed in the NB-OMP group, it was comparable in both groups by the end of the study period. Disease activity prior to therapy, but not extent, was found to influence control of activity in both groups. Thus, NB-UVB is a safe sole therapeutic tool in vitiligo management. Not only does it efficiently achieve repigmentation, but also it is a comparable stabilizing tool for systemic corticosteroids in spite of slightly delayed control. CONCLUSION: NB-UVB is the only well-established vitiligo therapy that can be used solely whenever corticosteroids are contraindicated or immune-suppression is unjustified. Nonetheless, its combination with corticosteroids expedites response and improves compliance.

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.

Noncultured epidermal suspensions obtained from partial-thickness epidermal cuts and suction blister roofs for vitiligo treatment: A prospective comparative study.

BACKGROUND: The treatment options for vitiligo are either nonsurgical, including medical treatments and phototherapy, or surgical, including autologous transplantation methods. Noncultured epidermal suspension transplantation is indicated for the treatment of stable vitiligo not responding to either medical treatment or phototherapy. Variable results have been reported for the various techniques used for the preparation of this suspension. AIM: To compare the outcome between suction blister roof grafts and partial-thickness epidermal cuts for the preparation of noncultured epidermal suspensions for the treatment of stable vitiligo. PATIENTS AND METHODS: Forty patients with localized stable vitiligo lesions resistant to conventional therapy were included in the study. They were randomly divided into two groups for treatment with noncultured epidermal suspension grafting. The suspensions in groups I and II were obtained from suction blister roofs and partial-thickness epidermal cuts, respectively. Repigmentation grade, color match with the surrounding skin, and any side effects were compared between the groups. RESULTS: In group I, complete repigmentation was achieved in 6 cases while repigmentation was considered excellent in 8 cases; very good, 4 cases; and no response, 2 cases. In group II, complete repigmentation was achieved in 4 cases, and repigmentation was considered excellent in 16 cases. The color of the repigmented area matched the normal surrounding skin in 70% of the cases in group I and 40% of the cases in group II. CONCLUSION: Both techniques yielded comparable repigmentation results with advantages and disadvantages of both techniques.

Factors affecting the outcome of the suction blisters using two different harvesting techniques in vitiligo patients.

BACKGROUND: Suction blister grafting (SBG) technique has been used for long to treat various skin conditions. Different suction methods have been used such as syringes, Chinese cups, and suction device. There are some limitations of its use as time consumption, failure of induction or incomplete blister formation and pain. AIM: The aim of this work was to evaluate the outcome of using two different suction techniques, namely the syringes and the Chinese cups in induction of suction blisters. The effect of the device diameter and preheating of the donor area on the suction blister induction time (SBIT) was studied. The effect of saline injection in the blister formation and its completion was also evaluated. METHODS: The study was a left-right comparative study that included 50 patients with stable nonsegmental vitiligo. They were classified into four groups: Group 1 included 15 patients where different diameters of syringes (1.3, 1.7, and 2 cm) were compared against each other, group 2 included 15 patients where different diameters of cups (2, 3.5, and 5 cm) were compared against each other, group 3 included 20 patients subdivided into two groups; 10 patients each, where the effect of preheating the skin on blister induction was tested with use of cups (3a) and syringes (3b). Lastly, group 4 included randomly chosen 40 incomplete or multilocular blisters where the effect of saline injection on blister completion and coalescence of multilobulation was examined. SBIT was calculated in all patients. RESULTS: The use of the small diameter syringes or cups gave shorter SBIT; however, the difference, which was significant between all sizes of cups, was significant between the 1.3- and 2-cm-diameter syringes only. Preheating of the donor area shorten SBIT significantly. No complications were reported at the donor site except for transient postinflammatory hyperpigmentation in all patients. CONCLUSION: The small diameter syringes or cups and preheating of the donor area shorten the SBIT, while intra-blister saline injection increased the blister size and turns the multilocular blisters to unilocular ones.

Clinical evaluation of interrupted versus continuous narrowband ultraviolet B phototherapy in nonsegmental vitiligo treatment: A prospective randomized comparative study.

Phototherapy is the pillar of vitiligo treatment. One of its main obstacles is noncompliance. It was noticed that patients continue to repigment even after stopping sessions, so the idea of interrupted phototherapy emerged. To evaluate the effectiveness of interrupted versus continuous NB-UVB in nonsegmental vitiligo treatment. A prospective randomized comparative study of 23 patients with bilateral, nonsegmental vitiligo with no age or sex limits. All patients were treated with NB-UVB phototherapy for 1 month, after which one side of the body received continuous therapy (Side A) and the other received an interrupted course (Side B) for a total of 6 months. Two more groups of 10 patients were enrolled to exclude the systemic effect of NB-UVB. One group received continuous NB-UVB treatment, and the other received interrupted courses for 6 months. Evaluation of the results was performed clinically, by digital photography, planimetry and Vitiligo Area Scoring Index (VASI) prior to and 3 and 6 months after treatment. There was a significant clinical improvement in Group 1 compared to baseline (p < .05). However, there was no significant difference between the sides with regards to the clinical evaluation, point counting, and VASI scores (p > .05). When comparing the other two groups, there was a significant clinical improvement in each group after 6 months of treatment compared to baseline (p < .05), while there was no significant difference between them (p > .05). The current study suggests that interrupted NB-UVB phototherapy is a good alternative to continuous treatment with improved patient compliance, fewer side effects, and a lower cost of treatment.

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.

Syringes versus Chinese cups in harvesting suction-induced blister graft: a randomized split-body study.

BACKGROUND: Suction blister grafting (SBG) is a technique where the pigmented epidermis is harvested from the donor site by induction of a blister using different suction methods as syringes, Chinese cups, suction device, etc. However, pain, time consumption, incomplete blister formation, and failure of blister development are the main limitations. OBJECTIVE: To compare between cups and syringes of similar diameter in inducing suction blisters. PATIENTS AND METHODS: In 30 patients with stable nonsegmental vitiligo, 2-cm-diameter (20 ml) syringe was applied on the anterolateral aspect of one thigh and a 2-cm-diameter cup on the corresponding site of the other thigh where right and left sides were chosen randomly. Patients were observed untill complete blister development or for a maximum of 3 hours. Suction blister induction time (SBIT) and the blister diameter were recorded for each patient. Pain during the process of induction was evaluated. RESULTS: Incomplete blister development was noted in 9 out of 30 (30%) with 2 cm syringes and 6 out of 30 (20%) with the similar diameter cups with no significant difference (P = 0.49). No significant difference was found between SBIT induced by the 2 cm syringes and the similar size cups (101.17 ± 68.14 minutes, 98 ± 56.84 minutes, respectively) (P = 0.85). Meanwhile, blister diameter induced by either syringe or cup was not significantly different (P = 0.37). Anesthesia was for short duration with xylocaine, and pain was intolerable in both sides in the first seven patients. A combination of xylocaine and bupivacaine was used with prolonged loss of pain in 17 of the remaining 23 patients and tolerable pain in six patients similarly in both sides. CONCLUSION: According to present results, the differences in SIBT, diameter of blisters, and number of complete blister formation induced by either syringes or cups of similar size were not significant. Therefore, whatever the available and feasible technique for the surgeon will be the ideal choice. A combination of xylocaine and bupivacaine is recommended to overcome the accompanying pain of the procedure.

CXCL-10 and Interleukin-6 are reliable serum markers for vitiligo activity: A multicenter cross-sectional study.

This cross-sectional multicenter study aimed to evaluate serum CXCL-10, as an activity marker for vitiligo, and compare it with other putative serum and tissue markers. Serum CXCL-10 was compared to interferon gamma (IFN-γ), interleukin 6 (IL-6), and IL-17 using ELISA in 55 non-segmental vitiligo patients (30 active and 25 stable) and 30 healthy controls. Marginal skin biopsy was taken for immunohistochemical evaluation of CD8+T cells and CXCL-10+ve cells. Serum levels of CXCL-10, IL-17, and IL-6 were elevated in all vitiligo patients compared to controls (p < .05). All investigated serum markers were higher in active versus stable vitiligo. Tissue expression of CXCL-10+ve cells and CD8+ve T cells was stronger in vitiligo patients compared to controls, and tissue CXCL-10+ve cell expression was stronger in active versus stable cases. Positive correlations were noted between the different serum and tissue markers. CXCL-10 was the most specific, whereas IL-6 was the most sensitive serum marker to distinguish active from stable disease.

Simultaneous improvement and worsening of vitiligo lesions during the course of NB-UVB phototherapy; vitiligo may not act as one unit.

Re-pigmentation and stabilization are the two ultimate goals of any re-pigmenting plan designed for vitiligo management. Furthermore, whether the improvement of some vitiligo lesions could be considered a guarantee for a similar response and/or stabilization of the rest of the lesions or not, remains to be clarified. To evaluate the behavior of non-segmental vitiligo (NSV), while on narrow band-ultraviolet B (NB-UVB) phototherapy. 25 patients with stable generalized NSV were included and received NB-UVB twice weekly. For the sake of ensuring accuracy of follow up, up to four lesions were randomly chosen in each patient and regularly measured using the point counting technique. The over-all point counting technique of all included patients showed a significant reduction (18.5 ± 8.4 cm2 to 8.2± 3.1 cm2 ) after 6 months of therapy (p < .001). Nine patients (36%), showed mixed response in the different lesions. Improvement was documented in some lesions, while other lesions showed no response or even worsening. No significant correlations were detected between the behavior of vitiligo during NB-UVB and any of the demographic or clinical data of the patients. NB-UVB is a pillar in the management of vitiligo, however close follow-up of the patient as a whole and his lesions, by both subjective and objective measures are mandatory to detect activity as early as possible, as vitiligo at many times may not act as one unit. This early detection of activity and the subsequent change in the treatment policy may ultimately change the final outcome of treatment.

Repigmentation in vitiligo: position paper of the Vitiligo Global Issues Consensus Conference.

The Vitiligo Global Issues Consensus Conference (VGICC), through an international e-Delphi consensus, concluded that 'repigmentation' and 'maintenance of gained repigmentation' are essential core outcome measures in future vitiligo trials. This VGICC position paper addresses these core topics in two sections and includes an atlas depicting vitiligo repigmentation patterns and color match. The first section delineates mechanisms and characteristics of vitiligo repigmentation, and the second section summarizes the outcomes of international meeting discussions and two e-surveys on vitiligo repigmentation, which had been carried out over 3 yr. Treatment is defined as successful if repigmentation exceeds 80% and at least 80% of the gained repigmentation is maintained for over 6 months. No agreement was found on the best outcome measure for assessing target or global repigmentation, therefore highlighting the limitations of e-surveys in addressing clinical measurements. Until there is a clear consensus, existing tools should be selected according to the specific needs of each study. A workshop will be conducted to address the remaining issues so as to achieve a consensus.

Elevated homocysteine levels in suction-induced blister fluid of active vitiligo lesions.

BACKGROUND: Vitiligo is the most prevalent acquired pigmentary disorder as a result of destruction of melanocytes. Several studies have reported increased serum levels of homocysteine (Hcy) in vitiligo patients which may be the result of decreased Vitamin B12 and folic acid levels. In addition, homocystinuria is associated with pigmentary dilution. On the other hand, other studies reported normal serum homocysteine levels. OBJECTIVES: Our aim was to study the Hcy level in active vitiligo patients both in serum and in suction blister fluid obtained from the lesional skin. METHOD: A total of 30 patients with active vitiligo of both sexes and 30 healthy volunteers were enrolled in this study. Sera from the blood and from lesional induced bullae were obtained from the patients and controls and were assayed for Hcy by enzyme-linked immunosorbent assay (ELISA). The collected data were analyzed by SPSS version 17. RESULTS: There were no significant differences in the serum levels of Hcy between patients and healthy controls, however, the increase in Hcy level was highly statistically significant in the patients' lesional induced bulla compared to the healthy controls. There was no significant difference in Hcy levels between males and females and between patients with negative or positive family histories of vitiligo. CONCLUSION: The presence of a high homocysteine level in active vitiligo lesions points to a local event occurring in this lesion, which is not reflected as an increase in the patient's serum level.

The effect of latanoprost on vitiligo: a preliminary comparative study.

Latanoprost (LT), a prostaglandin F 2alpha (PGF2a ) analogue used in the treatment of glaucoma, was found to induce skin pigmentation in guinea pigs in addition to its known periocular and iridal pigmentation side effects. This study aims to evaluate the efficacy of topical LT in the induction of skin repigmentation in patients with vitiligo and to compare its potency with narrow band ultraviolet (UV) B (NB-UVB). The result of their combination was also assessed. This study involved 22 patients with bilateral and symmetrical vitiligo lesions, stable for the last three months, divided into three groups: group I, to evaluate LT vs. placebo; group II, to evaluate LT vs. NB-UVB; and group III, to evaluate the effect of their combination. The response to treatment was evaluated by taking photographic records of the treated lesions with follow-up photography every two weeks. After three months, assessment of the degree and extent of repigmentation was performed. Follow-up assessment was done six months after termination of the trial for the persistence of pigmentation, recurrence, or development of any side effects. LT was found to be better than placebo and comparable with the NB-UVB in inducing skin repigmentation. This effect was enhanced by the addition of NB-UVB. LT could be a promising treatment for vitiligo, especially the periocular variant. Its effect on skin repigmentation could be enhanced by NB-UVB exposure.

Beyond vitiligo guidelines: combined stratified/personalized approaches for the vitiligo patient.

'Vitiligo' is a word that bears endless possibilities and no promises. Each vitiligo patient has a different story that demands a different therapeutic approach. Even though great efforts have been made to evaluate, study, compare and document the different therapeutic modalities available for vitiligo, clearly handling their modes of actions as well as their side effects and establishing clear stratified guidelines, numerous dilemmas are frequently met on practical grounds. 'Stabilize', 'repigment', 'depigment' or 'camouflage'? 'for whom and how do we achieve the best results' ? 'Separately or in combination ? - questions that need to be answered and decisions need to be taken in the appropriate timing and altered when the necessity arises. In the current viewpoint, we have utilized the available knowledge and exploited years of experience in an attempt to go beyond the guidelines to set the rationale for an optimal and personalized therapy, within the framework of a stratified approach.

Clinical study of nail changes in vitiligo.

Both vitiligo and alopecia areata (AA) are associated together, associated with other autoimmune diseases, and autoimmunity is one of the important theories in their etiology. Nail changes are a known association with AA, thus we hypothesized that nail changes can be found in vitiligo patients. On revising the literature, only two types of nail changes were described in association with vitiligo. Our aim was to study the frequency and types of nail changes among vitiligo patients in comparison with normal healthy volunteers. This multi-centric study was carried on 91 patients with vitiligo, as well as 91 normal healthy control subjects who were age- and sex-matched. Nails were examined for changes in nail plates as regards striations, texture, curvature, dystrophy, and pigmentation. The presence or absence of the thumb lunula was also reported. Nail changes were observed in 62 patients (68.1%) and 46 (50.5%) control subjects with a statistically significant difference (P = 0.016). Longitudinal ridging and absent lunula were significantly higher in patients than in the controls (P = 0.001 and 0.037, respectively). Other reported nail abnormalities in the current study included punctate leukonychia, pitting, flag sign, and Terry's nails. Awareness of this association will widen the clinician's perspective to carefully examine the nail changes in vitiligo patients and conversely examine patients with nail changes for vitiligo.

Effect of PUVA therapy on melanocytes and keratinocytes in non-segmental vitiligo: histopathological, immuno-histochemical and ultrastructural study.

BACKGROUND AND AIMS: Psoralen ultraviolet A (PUVA) is an important modality in treating vitiligo. Its effect on melanocytes and keratinocytes is not sufficiently studied. In this work, we investigated 30 cases of non-segmental vitiligo regarding the changes of melanocytes and keratinocytes in both vitiliginous and nearby areas before and after PUVA therapy. METHODS: Three skin biopsies were obtained from each patient from the vitiliginous, marginal and perilesional areas before and after 12 months of PUVA. Biopsies were examined histologically using haematoxylin and eosin, Masson-Fontana stains and 3,4-dihydroxyphenylalanine (DOPA) reaction and histochemically using human melanoma black-45 (HMB-45) antibody while ultrastructural examination was performed on six patients. Control biopsies were taken from five healthy volunteers. RESULTS: In 10% of pretreated biopsies from the centre of vitiligo lesions, scanty melanocytes were detected histologically and ultrastructurally, while they did not stain with DOPA or HMB-45 antibody suggesting that these melanocytes were inactive. Moreover, degenerative changes were detected by electron microscopy in both melanocytes and keratinocytes in all areas. After PUVA therapy, obvious improvement of the histopathological changes occurred with significant increase in active melanocytes. The degeneration of melanocytes and keratinocytes was also reduced at the ultrastructural level. CONCLUSION: Vitiligo affects both melanocytes and keratinocytes causing degenerative changes. These changes were present in both the leucodermic and the apparently normal perilesional skin. PUVA increases the number of active epidermal melanocytes in the three tested areas and recovers the melanocyte and keratinocyte degeneration.

A new morphometric technique for assessment of melanization in skin of guinea pigs.

BACKGROUND: The degree of melanization is an important finding in many skin disorders. An objective measurement of melanin density is needed to achieve an accurate evaluation. OBJECTIVES: The present work aims at translating the subjective increase of melanin particles after narrow band ultraviolet-B (NB-UVB) irradiation into objective numerical values ready for statistical analysis. MATERIALS AND METHODS: This study had involved 18 guinea pigs that were exposed to biweekly sessions of NB-UVB radiation for 4 weeks to induce skin pigmentation. Two skin biopsies were obtained from each animal; the first before treatment and the second at the end of the study, using 5 mm punch and stained with hematoxylin and eosin and Masson-Fontana (MF) stains. Surface area of both the epidermis (ESA) and the melanin particles (MPSA) were measured in µm(2) using a software supplied with Olympus light microscope. The MPSA/ESA percentage was calculated for each biopsy. The results before and after NB-UVB exposure were compared and statistically analyzed. RESULTS: In the MF-stained sections, the mean ± SD of the MPSA/ESA percentage were 0.24 µm(2) ± 0.09 and 6.21 µm(2) ± 2.45 at the start of the study and at its end, respectively, with a highly significant difference (P < 0.001). CONCLUSION: This technique offers a new methodology for an accurate numerical evaluation of epidermal melanization.