Vitiligo is a common depigmenting disorder with profound stigma. The published prevalence of vitiligo is 0.5% to 1%. Large studies in China, India, and Denmark have found the prevalence to be .093%, 0.005%, and 0.38%, respectively. Gujarat, India is considered to have the highest prevalence in the world, at about 8.8%. Men and women are equally affected [1]. In a meta-analysis , the prevalence of vitiligo were 0.1% (0.1%, 0.2%) in Asia, 0.4% (0.1%, 0.7%) in Africa, 0.2% (0.1%, 0.4%) in America, 0.4% (0.2%, 0.5%) in Europe, 1.2% (0.5%, 1.8%) in Oceania (only one study) and 0.1% (0%, 0.1%) in Atlantic, respectively [2].

Vitiligo may develop at any age, the median age of onset is about 20-23 years, i.e. about half the individuals develop vitiligo before the age of 20 years. About a quarter of those affected by vitiligo were less than 10 years of age at onset [3,4,5]. One fourth to one third of patients with vitiligo have family members with disease and the disease is transmitted in a multifactorial genetic pattern.

This study also demonstrated that close biologic relatives have an increased risk of developing vitiligo compared with controls [5,6]. Hann et al, [7] found that progressive vitiligo was associated with a positive family history, non-segmental clinical type, and longer duration of disease, Koebner’s phenomenon and mucous membrane involvement [7].

Other workers have also listed prognostic factors in vitiligo. A good prognosis is expected in lesions on neck and face and in colored races [8]. A poor prognosis may be associated with lesions on the so-called resistant sites such as bony prominences, non-fleshy, non-hairy and mucosal areas, association of greater percentage of white hair, persistent friction and itching on the affected area.

Emotional labiality and psychic turmoil associated systemic ailments, here do familial background, old age and iatrogenic factors injudicious use of topical and systemic medication particularly the photochemotherapeutic agents [9]. Some of those prognostic factors refer to the likely response to therapy while others to the progression of disease. However, little information is available on the risk factors for developing extensive vitiligo.

Here, the present study look >5% body surface area involvement as the criteria of extensive vitiligo.

Data analysis: The frequency of evaluating associated clinical factors among the cases and controls were used to evaluate the extensive vitiligo’s association with risk factors (disease risk associated exposure).

The analysis was done in two stages. In the first stage, the association of various clinical factors was evaluated which may be potential risk factors with extensive vitiligo.

In the second stage, the odds ratio (OR) was calculated to measure the association between the clinical characteristics (exposure) and extent of affection( outcome), to determine the independent significant clinical factors associated with extensive vitiligo, which can be designated as risk factors for extensive vitiligo. In this study, considered p<0.05 was considered as statistically significant.

Ethical consideration: Prior to selection in the study, an informed consent of all the patients was obtained. The patients were given the choice of whether they want to participate in the study or not.

Any scoring system: The surface area of the skin involved by vitiligo was measured using the Lund and Browder [10] chart estimates for adults and infants. Generalized vitiligo was classified with more than 5 percent of the body surface area in the study as cases

Surgical procedure if any: No Surgical intervention was done.

Two hundred and eleven patients were evaluated. There were 113 men and 98 women. The age of the patients varied from 4½ years to 65 years (Mean 28.72+SD 14.89).

There were 113 cases and 98 controls. Out of them, 73 cases and 67 control patients have age of onset less than 20 year (p>.05).

Table 1 shows the distribution of age at onset, the mean age at onset was 19.07+13.51 (+SD) years.

Table-1: Distribution of age at onset in vitiligo patients.

Table-5: Odds Ratio of the parameters came as significant in chi-square test.

Significance level p=.0001]. Hann et al [7] found that patients who developed new lesions in the preceding 3 months had disease for a longer than those who did not have new lesions.

The mean duration of patients with and without progression of vitiligo was 8.1 and 4.2 years, respectively these difference were significant (Students t-tests, P<0.05).

Once again, there is a possibility that patient with long standing disease would report only their disease became active while patients with relatively early disease may seek care more often. So, duration of disease can be considered as one risk factor for extensive vitiligo. A community based study may help to clarify these issues.

Koebner’s phenomenon was found to be significant associated with extensive disease on bivariate analysis, when the odds ratio was calculated, it was OR-.2.427, 95% CI-.1.39-4.23, Significance level p=.0018 in the present study. Different subtypes of KP, as per the study are [KP1, by history; KP2A and KP2B, by clinical examination (A, lesions on friction areas; B, linear, artefactual lesions).

Koebner”s Phenomenon was significantly associated with larger body surface area involvement in vitiligo in the presence of any KP subtype (p=0.038). The body surface area (BSA) was significantly (P < 0·001) higher in the presence of any KP subtype [12]. An association had found between Koebner’s phenomenon and the development or extension of lesions in the previous 3 months. In that study [7], Koebner’s isomorphic phenomenon was present in 84 patients (21%) of whom 80 showed progression. Koebner’s phenomenon was not present in 316 patients (79%) and 275 of these patients showed progression.

These differences were significant (Fisher’s exact test p<0.05). The absence of an association with extensive disease may indicate that Koebner’s phenomenon is associated with the developed of new lesions but not with the number and size of new lesions and the eventual extent of disease. In another recent study, koebners phenomenon is significantly associated with involvement of more BSA in comparison to patients with no Koebners Phenomenon [13]. Active progressive disease was positively associated with positive KP (OR, 1.8; p=0.02). Moreover, disease duration longer than 5 years was significantly more associated with positive KP (OR, 2.3; p＜0.0001).

Leukotrichia (vellus and terminal) was significantly higher in the 32/51 (62.7%) patients with generalized bilaterally symmetrical vitiligo in comparison to the 10/31 (32.3%) patients with acrofacial vitiligo and the 4/16 (25.0%) patients with unclassified vitiligo (P= 0.004). Neither of the two patients with focal vitiligo had leukotrichia but the only patient of universal vitiligo had. Vellus hair involvement was significantly higher in generalized bilaterally symmetrical vitiligo than in acrofacial or unclassified vitiligo. The incidence of scalp leukotrichia also was higher in generalized symmetrical vitiligo than in acrofacial vitiligo. The Vellus Score showed significant associations with Vitiligo Area and Severity Index [16].

It has long been recognized that depigmentation of the mucosa and hair within lesions are poor prognostic indicators for regimentation [9,17,18]. The usual explanation for this has been lack of follicular melanocyes to repopulate depigmented macules. The association with extensive disease cannot be explained on the same grounds. Damage to follicular melanocytes may represent a greater degree of disease activity than depigmentation confined to epidermal melanocytes and thus extensive disease may be more likely in such patients. The current study noted the presence of leucotrichia but did not recorded its extent. The evidence for an association would be stronger if it was demonstrated that patients who had widespread leucotrichia involving many lesions had more extensive disease. This may be worthy of further study.

Interestingly, a previous study [7] had found an association of progressive vitiligo with mucosal involvement. In that study 74% (298/400) with mucosal involvement of whom 255 showed progression: 104 had no mucosal involvement and 100 showed progression. This difference was significant (Fisher’s exact test, p> 0.05) and appears to indicate a protective effect of mucosal involvement. The pure mucosal type of vitiligo was not observed in our patients, but mucosal involvement in association with other clinical variants was seen in our patients with late-onset vitiligo and was significantly more common than in the early-onset group.

The development of symmetrical lesions is generally considered to indicate a more widespread or active process in several diseases including vitiligo. So, symmetrical lesions developed early in extensive vitiligo patients may be valued as risk factor.

A study on effect of ageat onset on disease characteristics in vitiligo, Patients with disease onset after 30 years had a significantly higher association with precipitating factors such as trauma, stress, and drugs in comparison with early-onset vitiligo (p< .004). However, the difference did not reach statistical significance when these factors were analyzed individually.

There was a significantly higher association with other nonautoimmune diseases (p= .05), a higher incidence of positive family history (p< .0001), and a higher association with leukotrichia (p< .002) in late-onset disease. Early-onset nonsegmental vitiligo was associated with a higher incidence of photosensitivity and pruritus compared to early-onset segmental vitiligo [21]. Theydidn’t mention whether vitiligo in late onset are more extensive, but presence of multiple factors may explain the association of extensive vitiligo. In one of the largest series of childhood vitiligo, Analysis of this group of patients revealed that early-onset childhood vitiligo was more likely to progress and involve a greater percentage of BSA [22].

Previous studies have indicated a correlation between the site of a lesion and its propensity to spread to other areas [23]. They also indicated that the response to treatment varies according to the site of the lesion when initial sites were the posterior trunk and hands, there was more widespread progression to other body areas, whereas there was less progression when the initial sites were the face, and upper or lower extremities[9,18,24,]. Site of lesion also important for therapeutic purpose, as few areas are more treatment responsive(face) than others [25].

They also inferred that the prognosis of vitiligo may be predicted by the location of the initial lesions; however, certain factors like Male sex, patient age of 15 years or under, and duration of disease of 2 years or less showed increased repigmentation with statistical significance. Therefore, these factors may be good prognostic indicators [25]. In the present study, no association was observed between the site of onset and extensive vitiligo (p = 0.0565).

The present study have taken some common clinical factors associated with extensive vitiligo, drawn the relation and significance in these association, so that the present study can designate them as risk factors.