Introduction
The normal pigmentation of the skin is due to the amount of melanin, type of melanin (eumelanin or pheomelanin), degree of vascularity, and thickness of Stratum corneum. Melanin is formed from tyrosine, through the action of tyrosinase in melanosomes of melanocytes. The melanosomes which transport melanin are transferred from melanocyte to a group of 36 keratinocytes called epidermal melanin unit.1 Hypopigmentary cutaneous disorders can be a consequence of different disturbances in the pigmentary system that include defects in the number or function of the melanocyte, decreased melanization of melanosomes, or decrease of the transfer process from melanocyte to keratinocyte. 2, 3 Disorders of hypopigmentation in children can be due to wide variety of congenital & acquired diseases. 4 Numerous skin conditions cause alteration in the normal pigmentation resulting in significant psychological morbidity due to cosmetic disfigurement and may also have profound psychological impact on parents of affected child because of associated stigma. 5 Common causes of hypopigmentation disorders are Pityriasis Alba, Vitiligo, Childhood leprosy, Nevus depigmentosus, Pityriasis versicolor, Post Inflammatory Hypopigmentation, Hypomelanosis Of Ito, Lichen Sclerosis Et Atrophicus, Pityriasis Lichenoid Chronica, Lichen Striatus, Oculocutaneous Albinism, Tuberous Sclerosis Complex, Hypopigmentary mosaicism.3
Materials and Methods
The study was conducted on patients attending the outpatient department of Dermatology, Venereology, and Leprology at a rural tertiary care center for the period of 1 year from july 2021 to June 2022. Approval was taken from Institutional Ethical Committee. This study was done in children aged 0–18 years with hypopigmented and depigmented lesions irrespective of sex. Patients were examined by an investigator for the diagnosis of hypopigmented and depigmented lesions. Informed consent of the parents or the guardian was taken. Data were recorded including patient name, age, sex, onset, characteristic of the lesion, presence of any skin diseases, prolonged illness, family history, etc., according to predesigned proforma. Photographs were taken for documentation after taking consent from the guardian. The following investigations were done depending on the clinical presentation‑skin biopsy was done in suspected cases of vitiligo, nevus depigmentosus, Hansen’s disease etc. KOH mount to identify any fungal etiology. Slit skin smear‑In suspected cases of Hansen’s disease. Data were analyzed using descriptive statistical analysis.
Results
In our study, among the 124 patients included the majority 29 (23.39%) of the patients were in the age group of 13-15, followed by 25 (20.16%) in the age group of 16-18 years, 20 (16.13%) 10-12 years, 19 (15.32%) in the age group of 0-3 years. Mean age was 9.8years. 64 (51.61%) of the patients were females and 60 (48.39%) males, thus female outnumbering males(F>M). History of atopy was perceived in 2 cases. Majority of patients had the hypopigmented lesions with insidious onset 108 (87.10%), followed by sudden onset among 11 (8.87%) and 5 (4.03%) had the hypopigmented lesions since birth. Face (52.42%) was the commonest area to be involved in the study followed by back (15.32%) and chest(13.71%). Out of the skin diseases detected, pityriasis alba (33), pityriasis versicolor(25), Polymorphic light eruption(22) and vitiligo(19) topped the list. Among 33 children with pityriasis alba, 17(51.5%) were boys and 16(48.4%) were girls. The majority (78.78%) of children were below 15 years of age and 96.9% had a duration of illness of fewer than 3 months. The face was the most commonly affected site in the majority (66.6%) of children. A history of atopy was perceived in only 2 cases(6%). In our study, out of 19 children with vitiligo, 8(42%) were boys and 11(58%) were girls. The majority (40%) of children had lesions over the face. A majority (63%) had an age of onset between 1-5years. vitiligo vulgaris was the most common type seen in 73.68% of cases. Among 25 children with pityriasis versicolor, 15(60%) were males and 10(40%) were females. The majority (88%) of children had a duration of illness of less than 3 months. The back and chest was the most commonly affected site in the majority (60%) of children.
Table 1
Comparison of the most common causes of hypopigmentation among various studies.
Figure 3
Lesions of Polymorphic light eruptions on Face of 12 year old girl with surrounding hyperpigmentation.
Figure 4
Polymorphic Light Eruption: Multiple Hypopigmented Micropapular lesions coalescing to form plaques.
Figure 6
Scaly hypopigmented perifollicular lesions of Pityriasis versicolor over forehead in a 4 year old child.
Discussion
The pattern and distribution of hypopigmented disorders in paediatric age group varies from one geographical location to another, due to differences in the external environment, climatic conditions, dietary customs, socioeconomic conditions, and cultural considerations. In our study of 124 cases, patients were enrolled from 0-18 years of which a maximum number of patients belongs to the age group of 13-15years (32%). In this study, 60 male and 64 female patients were enrolled with a male: female ratio of 0.94. Males predominated over females in other studies like Sudheer et al (M:F-1.12), Sori et al2 (M:F-1.17 and Soni et al7 (M:F-1.05). The mean age of onset was 9.2 years and the mean duration of illness was 5.8 months. In a study conducted by Sudheer et al 6 mean age of onset was 8.41 years, the mean duration of illness was 1.7 year and 10.7% of cases were present at birth. According to sori et al 2 mean age of onset was 7.36 years, the mean duration of illness was 1.64 years and in 9% of cases, lesions were present at birth. Soni et al7 calculate the mean duration of illness was 7.96 years, mean duration of duration was 1.12 years. In a study conducted by Babu AR et al 8 mean age of onset was 9.8 years, the mean duration of illness was 1.12year and 11% of cases were present at birth. Face (52.42%) was the commonest area to be involved in the recent study followed by the back (15.32%) and chest (13.71%). This was in concordance with the study done by Sudheer et al,6 Sori et al, 2 soni et al,7 Babu AR et al. 8 In the present study of 124 cases, the commonest cause of cutaneous hypopigmentation was pityriasis alba seen in 25.76% of children followed by pityriasis versicolor in 21.97%, polymorphic light eruption in 17.42%, vitiligo in 15.9%, a primary disorder of hypopigmentation in 8%, other causes of post-inflammatory hypopigmentation in 11.29% and leprosy in 0.81% cases. In the study done by Pinto et al,3 the most common disorders of hypopigmentation in children were pityriasis alba, vitiligo, nevus depigmentosus, and tinea versicolor, which were comparable to our study In another study by Sudheer et al,6 most common hypopigmentary disorders were pityriasis alba seen in 39% children followed by pityriasis versicolor in 19.6%, vitiligo in 15.7%, post-inflammatory hypopigmentation in 12.7%, primary disorder of hypopigmentation in 7.3%. Soni et al7 observed most common cause of hypopigmented lesions in children was pityriasis alba seen in 27.23% of children followed by pityriasis versicolor in 21%, vitiligo in 19.33%, post-inflammatory hypopigmentation in 14%, primary disorder of hypopigmentation in 13%. According to Babu et al,8 the most common cause of hypopigmentation in the pediatric population is Pityriasis alba (28.9%) followed by Post-inflammatory hypopigmentation (19.8%), Vitiligo(15.7%) and Pityriasis versicolor (8.2%). In the study performed by Sori et al2 commonest hypopigmentary disorders were pityriasis alba seen in 24.70%, vitiligo in 20.4%, leprosy in 11.5%, nevus depigmentosus in 10.18%, and pityriasis versicolor in 6.2% cases. In our study, among 33 children with pityriasis alba, 17(51.5%) were boys and 16(48.4%) were girls. The majority (78.78%) of children were below 15 years of age and 96.9% had a duration of illness of fewer than 3 months. The face was the most commonly affected site in the majority (66.6%) of children. A history of atopy was perceived in only 2 cases (6%). Vinod et al,9 in their study of 200 cases of pityriasis alba, found 69% of their cases were below 15 years of age. Personal history of atopy was noted in 17% of patients. A majority (84.5%) of patients had lesions of less than 6 months duration at the time of presentation. In this study, out of 19 children with vitiligo, 8(42%) were boys and 11(58%) were girls. The majority (40%) of children had lesions over the face. A majority (63%) had an age of onset between 1-5years. vitiligo vulgaris was the most common type seen in 73.68% of cases. Jaisankar et al 10 reported that vitiligo vulgaris was the commonest type followed by segmental. A study conducted by Jain et al 11 on 35 vitiligo patients, observed that the most common site of onset of vitiligo was the face (25.71%) followed by the lower limb (20%). The most common pattern observed in childhood vitiligo was vitiligo vulgaris (48.5%), followed by focal vitiligo (25.7). In the study done by Sheth et al, 12 in which the most common area affected was the lower limbs (62%), followed by the face (46%). In the study done by Gupta et al, 13 the mean age was 8.45±2.34 years and the average duration was 1.9 years, and two patients gave a history suggestive of hypothyroidism. Handa and Dogra 14 have reported an autoimmune association in 1.3% of children with vitiligo. Mazereeuw-Hautier et al,15 have reported the association of thyroid function abnormalities without clinical disease in 11.23% of children with nonsegmental vitiligo but none with segmental vitiligo. In the present study, among 25 children with pityriasis versicolor, the majority (88%) of children had a duration of illness of less than 3 months. The back and chest was the most commonly affected site in the majority (60%) of children. In Jena et al16 study of Discussion Page 67 pityriasis versicolor in 271 children, the majority of children were aged 8–12 years (31.7%), but 10 infants were also affected. The face was the most affected site (39%) and extensive involvement was seen in 45 (16.6%) children with lesions on the back and shoulder. Ghosh et al 17 in their study on pityriasis versicolor, found it almost similar to the above observation. Most of the lesions were hypopigmented scaly macules and the most commonly involved sites were the chest, face, and back. These variations in results from other studies like more prevalence of PMLE could be attributed to different geographical locations, prevalent environmental factors, type of population studied, and cultural and socioeconomic factors.
Conclusion
Hypo-pigmented skin lesions in children are of great concern in society. They cause anxiety among children and their parents due to the social stigma attached to these conditions, especially in dark-skinned children. The variations in the prevalence of conditions could be attributed to different geographical locations, prevalent environmental factors, type of population studied, cultural and socioeconomic factors. Arriving at a diagnosis may pose difficulty at times. However correct knowledge of the condition can prove beneficial from both diagnostic and management point of view.
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