Indian Journal of Paediatric Dermatology

ORIGINAL ARTICLE
Year
: 2016  |  Volume : 17  |  Issue : 3  |  Page : 179--185

Profile of childhood vitiligo with associated ocular abnormalities in South India


Belliappa Pemmanda Raju, Umashankar Nagaraju 
 Department of Dermatology, Venereology and Leprosy, Rajarajeswari Medical College and Hospital, Bengaluru, Karnataka, India

Correspondence Address:
Belliappa Pemmanda Raju
Department of Dermatology, Venereology and Leprosy, Rajarajeswari Medical College and Hospital, Kambipura, Mysore Road, Bengaluru - 560 074, Karnataka
India

Abstract

Background: Vitiligo is a systemic autoimmune disease due to the loss of melanocytes from the epidermis. Very few reports in the literature are available about the ocular findings and associated cutaneous abnormalities in childhood vitiligo. Aims: Objective of this study was to evaluate the ocular findings, various clinical characteristics and associated cutaneous abnormalities of childhood vitiligo. Materials and Methods: We retrospectively analyzed the clinical data of children with vitiligo who presented to the Dermatology Outpatient Department from August 2011 to August 2014. All patients were assessed for the natural history, clinical characteristics, family history, and associated ocular and cutaneous abnormalities. Results: Of the total 180 children with vitiligo studied, 64 (35.6%) were boys and 116 (64.4%) were girls. The mean current age of the children visiting our hospital was 8 years. History of trauma prior to the onset of vitiligo was present in 13 patients (7.2%). The family history of vitiligo was present in 37 patients (20.6%). Most common clinical type of vitiligo seen in our patients was vitiligo vulgaris (n = 68, 37.8%), followed by segmental (n = 41, 22.8%). The most common site of initial lesion was head and neck followed by lower limbs. Leukotrichia was seen in 65 patients (36.1%), while Koebner phenomenon was observed in 48 children (26.7%). Vitiligo disease activity (VIDA) score of +4 was most commonly seen in 108 patients (60%), followed by +3 seen in 20 patients (11.1%). VIDA score 0 and −1 were seen in 15 (8.3%) and 22 (12.2%) patients, respectively. Cutaneous associations with vitiligo were found in 24 patients (13.3%). These were halo nevi in nine patients (5%), atopic dermatitis in six patients (3.3%), alopecia areata in four patients (2.2%), premature canities in three patients (1.7%), and nevus depigmentosus and lichen nitidus in one patient each (0.6%). Thirty-eight patients (21.1%) were found to have periocular depigmentation. Depigmented spots in the iris were seen in two patients (1.1%). Other findings were lamellar cataract and persistent papillary membrane in one patient each (0.6%). Conclusion: Childhood vitiligo in our study showed preponderance in females. Majority of patients (77.9%) had <5% body surface area involvement. Limited number of patients with ocular findings in comparison with adult population might suggest that childhood vitiligo patients do not have ocular pigmentary abnormalities in the beginning, but as they age or as the disease progresses they may develop ocular pigmentary changes. Anatomical localization of vitiligo to periorbital area may alert us to look for ocular findings.



How to cite this article:
Raju BP, Nagaraju U. Profile of childhood vitiligo with associated ocular abnormalities in South India.Indian J Paediatr Dermatol 2016;17:179-185


How to cite this URL:
Raju BP, Nagaraju U. Profile of childhood vitiligo with associated ocular abnormalities in South India. Indian J Paediatr Dermatol [serial online] 2016 [cited 2019 Nov 14 ];17:179-185
Available from: http://www.ijpd.in/text.asp?2016/17/3/179/179486


Full Text

 Introduction



Vitiligo is an acquired, idiopathic disorder characterized by circumscribed depigmented macules. Although various hypotheses have been proposed, including autoimmunity, viral infections, free radicals, and neural theories, the exact mechanism for the disappearance of functional melanocytes from the involved skin has not yet been clearly established.[1] Depigmentation of the eyelids and poliosis of the eyebrows and eyelashes are commonly seen in vitiligo. Multiple ocular abnormalities including uveitis, retinal pigment epithelial hypopigmentation, chorioretinal scars, pigment clumping, and iris transillumination defects are found in patients with vitiligo.[2] Worldwide, vitiligo is a relatively common cause of leukoderma. Vitiligo affects between 0.5% and 4% of the world population.[3] Half of all patients develop the disease in childhood and adolescence before 20 years, making vitiligo an important element of pediatric dermatology.[4] Of the total population of patients with vitiligo, between 23% and 26% are reported to be children <12 years. It is a psychologically devastating, cosmetically disfiguring disease, and is resistant to therapy. Hence, it causes emotional trauma in children that can have long-lasting effects on their self-esteem.[5]

Vitiligo has a negative impact on the quality of life of children.[6] There are very few reports [2],[7],[8],[9] in the literature about the ocular findings in vitiligo and also there is a paucity of data on the epidemiology of childhood vitiligo from India [5],[10],[11],[12],[13],[14] and worldwide.[15],[16],[17],[18] In this study, we aimed to evaluate the ocular findings and assess the profile and associated cutaneous abnormalities of childhood vitiligo as seen over 3 years.

 Materials and Methods



A retrospective analysis was made on records of the patients attending the pigmentary clinic of the Department of Dermatology for a period of 3 years from August 2011 to August 2014. All children <12 years of age with vitiligo were included in the study. A total of 180 children of both sexes were enrolled. Details regarding the age of onset, site of initial lesion, duration of disease, progression, and associated cutaneous disorders were obtained from the clinic notes. Precipitating factors such as trauma, illness, stress, and contact with chemicals were noted. History of ocular symptoms, atopic dermatitis, and systemic illness such as diabetes, thyroid dysfunction, anemia, and Addison's disease and family history of vitiligo, premature canities, atopic dermatitis, or any other autoimmune disorders was recorded. Details of dermatological examination and systemic examination were obtained. Ophthalmologic examination done by an ophthalmologist includes visual acuity, external examination, and dilated fundoscopy. The diagnosis of vitiligo was made based on the clinical features and Wood's lamp. Each case was classified into recognized patterns of vitiligo, namely focal vitiligo, segmental vitiligo, acrofacial vitiligo, lip-tip vitiligo, mucosal vitiligo, vitiligo vulgaris, and vitiligo universalis. Focal vitiligo was defined as single or few lesions localized to one body part not forming any specific pattern. Segmental vitiligo was characterized by the presence of depigmented macules arranged unilaterally in a localized area of the body having a dermatomal or blaschkoid pattern. Mucosal vitiligo was defined as unique involvement of oral or genital mucosa. Vitiligo vulgaris was described as multiple lesions predominantly occurring over the trunk, shoulders, arms, and thighs. Lesions occurring over face, neck, hands, forearm, feet, and legs were termed as acrofacial vitiligo. Lip-tip vitiligo was considered when lesions were limited to lips and periungual areas. When there was a complete or near-complete involvement of the body with depigmentation, it was classified as universal vitiligo. Vitiligo disease activity (VIDA) score was ascertained for all patients to grade the activity of the disease. VIDA is a six-point scale for assessing vitiligo activity.[19] Scoring is based on the individual's opinion of the present disease activity over time. Active vitiligo involves either expansion of existing lesions or appearance of new lesions. Grading is as follows: VIDA score +4 - activity of 6 weeks or less duration, +3 - activity of 6 weeks to 3 months, +2 - activity of 3–6 months, +1 - activity of 6–12 months, 0 - stable for 1 year or more, and −1 - stable with spontaneous repigmentation since 1 year or more. A low VIDA score indicates less activity. Laboratory parameters such as hemogram, peripheral blood smear, blood glucose, triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone levels were included for all patients.

 Results



Of the total 180 children with vitiligo in this study, 64 (35.6%) were boys and 116 (64.4%) were girls. The mean current age of the children visiting our hospital was 8 years, and most patients (70%) were in the age group of 7–12 years. The youngest child was 1-year-old. The mean age at onset was 6.8 years. About 82% of children were <9 years when the depigmentation started [Table 1]. Duration of disease varied from 1 month to 7 years with a mean duration of 15 months. History of trauma prior to the onset of vitiligo was present in 13 patients (7.2%), pyoderma in nine patients (5%), and varicella in five children (2.8%). Vitiligo affecting first-degree relatives (parents/siblings) and second-degree relatives (grandparents/uncles/aunties) was reported by 31 patients (17.2%) and six patients (3.3%), respectively. Th family history of premature graying was present in 22 patients (12.2%).{Table 1}

Most common clinical type of vitiligo seen in our patients was vitiligo vulgaris followed by segmental vitiligo [Table 2]. Among the segmental type of vitiligo, trigeminal dermatome was most commonly involved in 26 patients (63.4%) followed by sacral area in seven patients (17.1%). Body surface area involvement of <20% was seen in 154 patients (85.6%) and 135 patients (75%) of these had <5% body surface area involvement.{Table 2}

The most common site of onset was head and neck area followed by extremities [Table 3]. Leukotrichia was present in 65 patients (36.1%), while Koebner phenomenon was positive in 48 patients (26.7%). Perilesional and perifollicular pigmentations were seen in 15 patients (8.3%) and 22 patients (12.2%), respectively.{Table 3}

VIDA score of +4 was most commonly seen in 108 patients (60%), followed by +3 seen in 20 patients (11.1%), +1 and +2 seen in eight patients (4.5%), and seven patients (3.9%), respectively. VIDA score 0 and −1 were seen in 15 (8.3%) and 22 (12.2%) patients, respectively. Spreading nature (VIDA score 1–4) of disease was seen in 143 patients (79.5%) with 108 patients (60%) having increased activity of the disease in past 6 weeks (VIDA +4). Nonspreading nature of the disease (VIDA score −1, 0) was seen in 37 patients (20.5%).

Cutaneous associations with vitiligo were found in 24 patients (13.3%). These were halo nevi in nine patients (5%), atopic dermatitis in six patients (3.3%), alopecia areata in four patients (2.2%), premature canities in three patients (1.7%), and nevus depigmentosus and lichen nitidus in one patient each (0.6%). No associated systemic disease was found.

Thirty-eight patients (21.1%) were found to have periocular depigmentation. Depigmented spots in the iris were seen in two patients (1.1%), and both these patients had periocular depigmentation. Other findings were lamellar cataract and persistent papillary membrane in one patient each (0.6%).

 Discussion



Vitiligo is the most common depigmentary disorder; it is characterized by chalky or milky white macules of variable shapes and sizes with or without leukotrichia and lacks any epidermal changes. Vitiligo is common in India, having a prevalence of 0.46–8.8%.[20] Indian studies on childhood vitiligo have reported a prevalence of 2.6%.[13] There have been few studies that describe the clinical spectrum of vitiligo in children from India,[5],[10],[11],[12],[13],[14] that is, age 12 or younger, although it is stated that most cases of vitiligo are acquired early in life.[15] We have attempted to compare our findings with those in the previous studies. A comparison of the patterns of vitiligo and its associated disorders in different studies from India, including ours, is represented in [Table 4].{Table 4}

Age Distribution

A study by Handa and Dogra [14] showed the most common age at presentation to be between 9 and 12 years. In our study, the most common age at presentation was between 7 and 12 years. The mean current age of children visiting our hospital was 8 years. This is in agreement with the study by Kayal et al.[11] and Hu et al.,[17] where the children presented at a mean age of 7.85 ± 2.94 and 8.8 years, respectively. The youngest child in our study was 1-year-old. In a Chinese study [17] on childhood vitiligo (n = 541), eight children had skin lesions present at birth (focal 7, acrofacial 1),[5] whereas we did not have any case of congenital vitiligo.

Sex Distribution

A female preponderance in childhood vitiligo has been reported in most of the studies except a few [16],[17],[21] in which an almost equal incidence in boys and girls has been observed. The prevalence of vitiligo was found to be higher in girls than in boys (64.4 vs. 35.6) in our study. The male: female ratio was 1:1.8. The explanation could be that patients or parents worry more and tend to seek treatment for cosmetically disfiguring, depigmenting patches more frequently in girls.

Age of Onset

The disease onset is usually seen below 10 years of age. Handa and Dogra [14] reported that more than 50% of the cases had the onset of the disease between 4 and 8 years of age. Kayal et al.[11] reported it as 45.9% between the age of >8–12 years and Hu et al.[17] reported it to be 42.5%. The most common age group at which depigmentation initiated in our study was between 4 and 9 years, constituting 68.9% of the cases. The mean age at onset of childhood vitiligo in Indian studies reported are 6.2 years,[14] 5 years,[22] 6.9 years,[10] and 8.92 years.[5] The mean age at onset was 6.8 years in our study. When comparing the age at presentation and age at onset, age at presentation in most cases is between 7 and 12 years and age at onset is between 4 and 9 years of age. This difference between the age of onset and age of presentation could be because patients might ignore the initial lesion and seek treatment only after the disease progresses or may be on account of illiteracy, lack of awareness, and tendency to seek easily accessible treatment first. This variable period elapsed between the onset of disease and presentation to tertiary care center has been seen in other studies as well.[11],[14],[17]

Duration

The mean duration of disease in Indian studies reported are 18.6 months (range from 1-month to 10 years) and 1.36 years (range from 2 months to 8 years).[5],[10] Hu et al.[17] reported the mean duration of the disease of 1.6 years. Duration of depigmentation varied from 1 month to 7 years in our study and the mean duration before the first consultation was 14 months. This delay could be due to the stigma associated with vitiligo or traditional medications taken before reporting to us.

Site of Initial Lesion

Head and neck has been reported to be the most common site of onset in several studies.[11],[14],[16],[18] In our study also, the most common site of initial lesion was head and neck followed by lower limbs, genitalia, trunk, and upper limbs in that order. However, Jaisankar et al.[13] reported the various sites of onset to be lower limbs, head and neck, upper limbs, and thorax.

Precipitating Factors

The most common precipitating factor was trauma noted in 6.6% patients, showing vitiligo lesions at extra traumatic sites. An Indian study reported a history of trauma in 39.45%.[11] Other factors were pyoderma in 4.9% and varicella in 2.5%. However, a history of contact with chemicals was not seen.

Family History

A positive family history of vitiligo in children with vitiligo ranges from 3.3% to 35% in various studies.[13],[14],[15] In this study, 24.3% of children with vitiligo had a family history of vitiligo and 12.2% had a family history of premature graying. Halder et al.[15] also reported an increased incidence of premature graying in family members. Of the 20.5% of children with a family history of vitiligo, first-degree relatives were affected in 17.2% and second-degree relatives were affected in 3.3%. However, Handa and Dogra [14] reported that second-degree relatives were affected more than first degree ones (64.5% vs. 35.5%). Similarly, Sheth et al.[5] reported familial association in 14 patients (14%), among which nine patients had vitiligo in the second-degree relatives.

Type of Vitiligo

Childhood Vitiligo may present in various morphological patterns. In our study, vitiligo vulgaris was the most common clinical type seen in 36.9% followed by segmental type in 27% and focal in 17.2%. The most common pattern seen in most studies is vitiligo vulgaris, followed by focal and segmental vitiligo,[5],[14],[16],[17],[23] whereas acrofacial and mucosal vitiligo have a lower incidence. However, acrofacial type of vitiligo (38.1%) was observed to be the most common clinical type in children, followed by vitiligo vulgaris (27.2%), segmental vitiligo (16.8%), focal vitiligo (16.8%), and mucosal vitiligo (1.1%) in a study by Agarwal et al.[10] In our study, acrofacial vitiligo was seen in 10.7%. Jaisankar et al.[13] reported segmental vitiligo as the second most frequent presentation, occurring in 21% of patients, closely followed by focal vitiligo in 20.1%. However, Halder et al.[15] reported focal vitiligo as the second most common presentation. Segmental vitiligo has been reported more frequently in children in most studies [13],[15],[16],[24] but not all [14] because of the early onset, usually in the first decade of life, of segmental vitiligo. Among the children affected with segmental vitiligo, trigeminal dermatome was most commonly involved in either sex in our study. Hann and Lee [25] in their study on segmental vitiligo of all age groups reported similar findings. We observed mucosal vitiligo in 13.1%. Jaisankar et al.[13] reported a similar figure of 13.8%. Handa and Dogra [14] reported a considerably lower figure of 0.6%, while Halder et al.[15] had no patients with mucosal vitiligo. Lip-tip vitiligo was the least common type seen in our study population. Halder et al.[15] and Jiashankar et al.[13] reported acrofacial type to be the least common. Handa and Dogra [14] reported universal vitiligo to be the least common. Universal vitiligo was not observed in our study, which is in concurrence with earlier reports.[5],[10]

Body Surface Area Involvement

Handa and Dogra [14] reported <20% of body surface area involvement in 96.4% and majority of them (86.7%) had <5% body surface area involvement. In another Indian study,[12] 74.28% had <5% body surface area involvement and 25.71% had 5–20% body surface area involvement. Our study showed body surface area involvement of <20% in 85.6% of children and majority among them (74.9%) had <5% body surface area involvement.

Vitiligo Disease Activity Score

In a recent Indian study,[11] +4 VIDA was noted in maximum (25.69%) patients followed by +1, +3, and +2 VIDA in 24.77%, 19.26%, and 14.68% patients, respectively. Stable disease was seen in 15.60% patients, and none showed spontaneous repigmentation. In majority of patients (84.40%), VIDA revealed that the disease was progressive. This could be accounted by the fact that the parents/patients usually reach tertiary care center in the event of progression of their disease extent and severity. They have a tendency to seek easily available treatment first. In another study by Sheth et al.,[5] VIDA score +4 was most commonly seen in 81 patients, followed by 3 seen in six patients, and +1 and +2 seen in two patients each. VIDA score 0 and −1 were seen in four and five patients, respectively. Progressive disease was seen in 91% patients, stable disease in 4%, and spontaneous repigmentation in 5% patients, respectively. In our study, VIDA score of +4 was most commonly seen in 60% patients, followed by +3 in 11.1% patients, and +1 and +2 in 4.5% and 3.9% patients, respectively. VIDA score 0 and −1 were seen in 8.3% and 12.2% patients, respectively. Progressive nature (VIDA score 1–4) of disease was seen in 79.5% patients with 60% having increased activity of the disease in past 6 weeks (VIDA +4). Stable nature of the disease (VIDA score −1, 0) was seen in 20.5% patients, which is in agreement with earlier studies.

Specific Features

Leukotrichia has been reported in 3.7–32.5% of patients, which is seen more frequently in the vitiligo vulgaris followed by segmental and focal vitiligo.[10] Our study showed leukotrichia in 41.8%, most commonly in vitiligo vulgaris variant, followed by segmental and focal vitiligo. Koebner phenomenon has been reported to occur in as many as 11.3–36.7% of all childhood vitiligo patients.[5],[11],[14] We observed Koebner phenomenon in 24.6% of children, most commonly in vitiligo vulgaris variant as similar to other studies. The increased incidence of koebnerization may be explained by increased proneness to trauma among due to higher mobility and playfulness in the pediatric population, and its occurrence is correlated with the activity of the disease. We observed perilesional pigmentation in 8.5% of children and perifollicular pigmentation in 12.3% of children. These observations have not been made in earlier studies.

Cutaneous Associations and Autoimmune Disorders

Cutaneous associations of vitiligo reported are halo nevi (2.5–34%),[14],[16],[17],[23] atopic dermatitis (2.8–9.3%),[10],[12],[18] and psoriasis (1.5%).[10] In our study, 5% of children had halo nevi and 3.3% had atopic dermatitis. Other cutaneous associations observed in our study were premature canities in 1.6% and nevus depigmentosus and lichen nitidus in 0.6% each. Earlier studies have reported premature graying in 4–4.4%.[13],[15] Segmental vitiligo associated with lichen nitidus and Down's syndrome has been reported earlier.[26] The reported frequency of associated autoimmune disorders in children with vitiligo is significantly less than that observed in adult vitiligo population. Different studies have reported the incidence of alopecia areata ranging from 0.3% to 3.4%.[10],[14],[15] In our study, 2.2% had alopecia areata, out of these one had alopecia universalis. No other autoimmune disorders were observed. Handa and Dogra [14] reported one patient each of diabetes mellitus, thyroid disease, Addison's disease, polyglandular syndrome, and pemphigus vulgaris in 625 children with vitiligo. Thyroid abnormalities were found in 9% of children in a recent study.[10]

Ocular Associations

Depigmentation of the eyelids and poliosis of the eyebrows and eyelashes are commonly seen in vitiligo. Because vitiligo affects all active melanocytes, ocular problems can occur in patients with vitiligo.[15] The reported frequency of ocular pigmentary abnormalities is 40% in vitiligo patients of all age groups, and some loss of visual acuity, poor night vision, or photophobia are seen in 5% of these patients.[27] Albert et al.[2] reported 27% of patients with vitiligo of all age groups to have some evidence of retinal pigment epithelium hypopigmentation and one-fourth of these patients had night blindness. Bulbul Baskan et al.[9] in a study of ocular findings in 45 vitiligo patients of all age groups reported peripapillary atrophy around the optic nerve in 15.6%, atrophy of the retinal pigment epithelium in 4.4%, and diffuse and focal hypopigmented spots on the retina in 2.2% each. It is evident that multiple ocular abnormalities may be found in patients with vitiligo. Many of the ocular findings are nonspecific in character and distribution but may be mostly ascribed to immunological processes in vitiligo.[9] Anatomical localizations, primarily periorbital and to a lesser extent genital vitiligo, seem to be the most probably alerting features for ocular findings.[9]

In an earlier study of ocular involvement in 32 patients of childhood vitiligo, 12 children exhibited some type of ocular findings, but no findings could be attributed specifically to vitiligo.[15] However, study by Al-Mutairi et al.[18] did not show patients having any ocular abnormality. Our study found 38 patients with periocular depigmentation and in two of these patients, depigmented spots in the iris were seen. Though the number of patients with ocular findings is less, the possibility of ocular findings in patients with periorbital location of vitiligo must be kept in mind. Other findings were lamellar cataract and persistent papillary membrane in one patient each. None of our patients had an evidence of retinal pigment epithelium hypopigmentation or night blindness. This difference of findings in comparison to adult onset vitiligo might probably suggest that childhood vitiligo patients do not have ocular pigmentary abnormalities in the beginning, but as they age or as the disease progresses they may develop ocular pigmentary changes. Frequent ocular examination in these children may be needed to document these changes, which may help in early therapeutic intervention for these patients.

 Conclusion



Childhood vitiligo in our study showed preponderance in females probably because patients or parents worry more and tend to seek treatment for cosmetically disfiguring, depigmenting patches more frequently in girls. Majority of patients (77.9%) had <5% body surface area involvement. Progressive nature of disease was seen in 79.5% patients, and stable nature of the disease was seen in 20.5% patients; limited number of patients with ocular findings in comparison with adult population might suggest that childhood vitiligo patients do not have ocular pigmentary abnormalities in the beginning, but as they age or as the disease progresses they may develop ocular pigmentary changes. Anatomical localization of vitiligo to periorbital area may alert us to look for ocular findings. This study highlights the need for regular follow-up of childhood vitiligo patients to look for associated involvement of the eye.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Ortonne JP. Vitiligo. In: Bolognia JL, Jorizzo JL, Rapini RP, editors. Dermatology. 1st ed. Toronto: Mosby; 2003.
2Albert DM, Wagoner MD, Pruett RC, Nordlund JJ, Lerner AB. Vitiligo and disorders of the retinal pigment epithelium. Br J Ophthalmol 1983;67:153-6.
3Ortonne JP, Bose SK. Vitiligo: Where do we stand? Pigment Cell Res 1993;6:61-72.
4Plettenberg H, Assmann T, Ruzicka T. Childhood vitiligo and tacrolimus: Immunomodulating treatment for an autoimmune disease. Arch Dermatol 2003;139:651-4.
5Sheth PK, Sacchidanand S, Asha GS. Clinico-epidemiological profile of childhood vitiligo. Indian J Paediatr Dermatol 2015;16:23-8.
6Njoo MD, Bos JD, Westerhof W. Treatment of generalized vitiligo in children with narrow-band (TL-01) UVB radiation therapy. J Am Acad Dermatol 2000;42(2 Pt 1):245-53.
7Albert DM, Nordlund JJ, Lerner AB. Ocular abnormalities occurring with vitiligo. Ophthalmology 1979;86:1145-60.
8Cowan CL Jr., Halder RM, Grimes PE, Chakrabarti SG, Kenney JA Jr. Ocular disturbances in vitiligo. J Am Acad Dermatol 1986;15:17-24.
9Bulbul Baskan E, Baykara M, Ercan I, Tunali S, Yucel A. Vitiligo and ocular findings: A study on possible associations. J Eur Acad Dermatol Venereol 2006;20:829-33.
10Agarwal S, Gupta S, Ojha A, Sinha R. Childhood vitiligo: Clinicoepidemiologic profile of 268 children from the Kumaun region of Uttarakhand, India. Pediatr Dermatol 2013;30:348-53.
11Kayal A, Gupta LK, Khare AK, Mehta S, Mittal A, Kuldeep CM. Pattern of childhood onset vitiligo at a tertiary care centre in South-West Rajasthan. Indian J Dermatol 2015;60:520.
12Jain M, Jain SK, Kumar R, Mehta P, Banjara N, Kalwaniya S. Clinical profile of childhood vitiligo patients in Hadoti region in Rajasthan. Indian J Paediatr Dermatol 2014;15:20-3.
13Jaisankar TJ, Baruah MC, Garg BR. Vitiligo in children. Int J Dermatol 1992;31:621-3.
14Handa S, Dogra S. Epidemiology of childhood vitiligo: A study of 625 patients from North India. Pediatr Dermatol 2003;20:207-10.
15Halder RM, Grimes PE, Cowan CA, Enterline JA, Chakrabarti SG, Kenney JA Jr. Childhood vitiligo. J Am Acad Dermatol 1987;16(5 Pt 1):948-54.
16Cho S, Kang HC, Hahm JH. Characteristics of vitiligo in Korean children. Pediatr Dermatol 2000;17:189-93.
17Hu Z, Liu JB, Ma SS, Yang S, Zhang XJ. Profile of childhood vitiligo in China: An analysis of 541 patients. Pediatr Dermatol 2006;23:114-6.
18Al-Mutairi N, Sharma AK, Al-Sheltawy M, Nour-Eldin O. Childhood vitiligo: A prospective hospital-based study. Australas J Dermatol 2005;46:150-3.
19Njoo MD, Das PK, Bos JD, Westerhof W. Association of the Köbner phenomenon with disease activity and therapeutic responsiveness in vitiligo vulgaris. Arch Dermatol 1999;135:407-13.
20Handa S, Kaur I. Vitiligo: Clinical findings in 1436 patients. J Dermatol 1999;26:653-7.
21Lin X, Tang LY, Fu WW, Kang KF. Childhood vitiligo in China: Clinical profiles and immunological findings in 620 cases. Am J Clin Dermatol 2011;12:277-81.
22Prakash P, Thappa DM. A clinical study of the spectrum of vitiligo in children versus adults and its associations. Indian Dermatol Online J 2013;4:250-1.
23Prcic S, Djuran V, Mikov A, Mikov I. Vitiligo in children. Pediatr Dermatol 2007;24:666.
24Nicolaidou E, Antoniou C, Miniati A, Lagogianni E, Matekovits A, Stratigos A, et al. Childhood- and later-onset vitiligo have diverse epidemiologic and clinical characteristics. J Am Acad Dermatol 2012;66:954-8.
25Hann SK, Lee HJ. Segmental vitiligo: Clinical findings in 208 patients. J Am Acad Dermatol 1996;35(5 Pt 1):671-4.
26Agarwal S, Guglani V, Kumar B. Down's syndrome with lichen nitidus and segmental vitiligo. Indian J Dermatol Venereol Leprol 2009;75:627-9.
27Drake LA, Dinehart SM, Farmer ER, Goltz RW, Graham GF, Hordinsky MK, et al. Guidelines of care for vitiligo. American Academy of Dermatology. J Am Acad Dermatol 1996;35:620-6.