CLINICOEPIDEMIOLOGICAL PROFILE OF PITYRIASIS VERSICOLOR IN A TERTIARY CARE HOSPITAL IN KATHMANDU, NEPAL

Pityriasis versicolor (PV) also known as Tinea versicolor is a benign, chronic superficial fungal infection of the skin caused by Malassezia furfur. It is characterized by dyspigmented macules with fine branny scales. The purpose of this study was to assess the epidemiological profile and clinical pattern of PV in a group of patients visiting a tertiary care centre of Nepal. A descriptive cross-sectional study was carried out including 150 patients diagnosed to have PV at the outpatient dermatology department of Nepal Medical College Teaching Hospital. Patients with the diagnosis of PV were included in the study. A detailed history was taken and it was followed by a thorough clinical examination. The findings of history and clinical examinations were documented in a predesigned proforma. Statistical Package for the Social Sciences (SPSS) version 16 was used to tabulate the data and analyze the results. There was a slight male preponderance with maximum patients of the age group 11 – 20 years. A majority of patients were students. Forty three (28.7%) patients had similar problem in close contacts and 42% had recurrent disease. Wearing of occlusive synthetic clothing was the commonest predisposing factor. Upper chest and upper back were the most involved sites. Hypopigmented macules were the commonest lesions in 72.7%. Coexisting seborrheic dermatitis (commonly pityriasis capitis ) was present in 44.67% of patients. Clinicoepidemiological profile of PV in our setting is similar to many studies done mostly in India. But few findings differ which indicates the need for further studies in Nepal especially from Terai regions where the prevalence is expected to be more. Department of Dermatology, Nepal Medical College Teaching Hospital, Attarkhel, Gokarneshwor-8, Kathmandu, Nepal


INTRODUCTION
Pityriasis versicolor (PV) also known as Tinea versicolor (TV) is a benign, chronic superficial fungal infection of the skin caused by Malassezia yeasts which are part of the many microscopic organisms that normally live on the skin. 1 It is characterized by discolored or depigmented, discrete or confluent scaly areas mostly involving the upper trunk. 2 Epidemiologically, PV is more frequently seen in people residing in tropical regions with prevalence as high as 40% whereas in temperate areas the prevalence is lower. 3 The point prevalence of PV in Nepal has been reported to be 8.9%. 4 Several factors are associated with increased risk of acquiring PV, like increased environmental humidity, application of oily preparation and creams (due to lipophilicity of the organism), corticosteroid overuse, genetic predisposition, malnutrition and hyperhidrosis. 5 Age wise, late teens and young adults have the increased risk of PV. [6][7][8][9][10][11][12][13][14][15][16] Though PV is pretty common in Nepal, very few studies have been conducted to look into the epidemiological and clinical characteristics of this disease. Besides, due to widely varying environmental factors, epidemiological and clinical profile of PV is expected to vary from one geographic location to another. Hence, this study was done with the aim of finding out the epidemiological profile, common predisposing factors and clinical profile of PV in Nepalese people.

MATERIALS AND METHODS
A descriptive cross-sectional study was carried out at the outpatient dermatology department of Nepal Medical College Teaching Hospital for a period of 18 months from January 2018 to June 2019. The sample size was calculated using the formula n = Z 2 p(1-p)/d 2 where n = sample size, Z = reliability coefficient (1.96 for 95% confidence interval), p = 9% (Point prevalence in Nepal in a study done by Walker et al was 8.9%) 4 and d = Absolute error (5% taken for this study). The study group comprised of 150 patients diagnosed as PV by a dermatologist. Patients presenting with hypopigmented or hyperpigmented macules with fine powdery branny scales were seen by a dermatologist. The macules were examined using a Wood's lamp and presence of yellow to golden yellow fluorescence was considered diagnostic of PV; and these patients were included in the study. A verbal consent was taken from all the patients at the time of diagnosis to include them in the study.
A detailed history was taken in a predesigned proforma which included patient's age, sex, occupation, duration, itching, history of recurrence, climatic influence, starting season, history of similar problem in family or contact, sharing of clothings, use of synthetic clothing and use of oil or talcum powder. A thorough clinical examination was done to determine the complexion of the patient, distribution of the skin lesions, color of the skin lesions and presence of seborrheic dermatitis (including pityriasis capitis or dandruff). The findings of history and clinical examinations were documented in the proforma. Statistical Package for the Social Sciences (SPSS) version 16 was used to tabulate the data and analyse the results. Ethical clearance was taken from the Nepal Medical College Institutional Review Committee.

DISCUSSION
Few of the results in our study were in concordance with previous studies but few facts differed. In our study there was a male preponderance (M:F = 1.27:1) and this was concordant with many other studies. [6][7][8][11][12][13][14][15][16][17][18] It is a well understood fact that men are involved in lots of outdoor activities because of which the hot and humid environment predisposes them to develop PV. In our study, there was only a slight preponderance in male which could be explained by the fact that females are more concerned about the appearance of their skin; and also in our community PV is confused with vitiligo, so that fear makes them consult a doctor immediately. In contrast to our studies, few studies have shown PV to be more common in female. 9,19 Studies by Kaur et al 21  PV commonly is a disease of teenagers and young adults. In our study also, the commonest age group was 11 -20 years followed by 21 -30 years. Similar  6,9,11 In several other studies it was found that 21 -30 years was the commonest age group involved. 7,8,12,15,16,18,20,21 But in contrast to these studies, Kambil and Thayikkannu et al have reported it to be commonest in 20 -40 years. 14,19 The fact that Malassezia yeasts (the causative organism of PV) is lipophilic 5 ; and that in adolescence and young adults there are hormonal changes with excessive activity of sebaceous glands, explains why this disease is common in this age group of 11 -30 years. 3 Besides, the other factor could be the trend of wearing occlusive synthetic clothing in the young generation today which could also act as predisposing factor. Childhood PV (<10 years) was seen in only 4.7% and only 2.7% of patients constituted more than 50 years. Many studies have found that PV is less common in children, 7,8,11,14,15,19,20 but in a study by Rijal et al in children of age group 0-14 years, the prevalence of PV was 56.4% of all hypopigmented macules screened. 23 In another study by Dwari et al, it was reported that 31% of the total cases of PV belonged to age group 0-14 years and 4.8% of patients were infants. 24 PV was found to be rare in people older than 50 years like in many other studies. 6,8,11,13,20 In our study, the students were most commonly affected by PV which is similar to other studies by Ghosh 6,8,11,12,14,18 This explains the fact why the adolescents and young adults are commonly involved. Besides they are also involved in lots of outdoor activities because of which sweating and sun can predispose them to develop this disease. Also, it was found that 28% of the patients in the age group 11 to 40 years used to share clothing and 30.65% of these patients wore occlusive synthetic clothing frequently. Housewives were the second most commonly affected similar to studies by Shah et al and Kambil. 12,14 For them the consultation would be important because of the aesthetic issue. In Nepal, there are lots of social stigma associated with vitiligo and many times the patients confuse PV with vitiligo and they consult a specialist only to clear that confusion.
The duration of disease ranged from 1 week up to 7 years which was similar to few other studies. 6,13,14 But in studies by Sharma et al and Banerjee et al up to 20 years duration has been recorded. 7,10 The recurrence rate of the disease was 42% which was comparable to the recurrence rate reported in many other studies ranging from 23.75% to 55.2%. [9][10][11]14,19 PV is known to occur more frequently in tropical climates and summer months. 25 Different studies conducted in different parts of the world have shown that PV is commonly seen in summer season. [6][7][8]14 In our study also 73.3% of the patients had the lesions starting in summer months.
PV is considered to be a contagious disease, so presence of similar problem in family is considered to be one of the predisposing factors.
In various studies, the family history was present in 6%, 16.8%, 25.5%, 34.22%, 38.3% and 44.8%. [6][7][8]11,14,24 and in our study 28.7% of patients gave history of similar disease in family members or close contacts. But in a study by Rao et al, spreading from parents to children has been seen to be more (13.3%) than spread among spouses (10%) and he has stated that hereditary factor may play role in the transmission of disease. 8 Overgrowth of the commensal fungus Malassezia occurs due to many predisposing factors like heat, moisture and occlusion of the skin by dressings, clothing or cosmetics (oil, talcum, etc.). 26 In our study only 4.7% patients used talcum powder and 14.7% used oil over the body, so these factors were insignificant. The most important factor which was significant was the use of occlusive synthetic clothing in 39.3%.
Because of the lipid requirement of the Malassezia species, PV is primarily found over the lipid rich areas of the body like chest, back, upper arm and face. 22 Trunk was found to be the commonest site involved in our study similar to other studies. 6,10,11,[14][15][16]19,21,27 Whereas in few studies, neck was the commonest site involved. 7,8,12,13 In different studies conducted in Venezuela and Africa, the commonest site reported was face followed by upper trunk. 28,29 In our study, the commonest site, trunk included upper chest and upper back which formed 52.70% of the total sites involved. In contrast to adolescent and adult age group, different studies have shown that face was the commonest site involved in children. 7,9,23,24,30 Banerjee et al in their study found that in children below 12 years lower limb and buttock were significantly more commonly involved. 10 In contrast, in our study, even in children (0-10 years), upper chest was the commonest site involved followed by upper back. Upper chest and upper back comprised the largest percentage of sites involved in patients up to 50 years old.
Skin dyspigmentation, either in the form of hypopigmentation or hyperpigmentation is most often the presenting complaint of patients with PV. The general concept is that in dark skinned individuals the lesions of PV are hypopigmented rather than hyperpigmented. 31  Malassezia yeasts have been associated in the pathogenesis of pityriasis capitis and seborrheic dermatitis besides PV. 34 The prevalence of seborrheic dermatitis has been found to be 10% (Ghosh et al), 11.6% (Rao et al), 26.20% (Kambil) and 31.9% (Banerjee et al). 6,8,10,14 But in our study, the prevalence of seborrheic dermatitis was 44.67% which was high compared to previous studies.
In conclusion, PV is one of the commonest superficial fungal infections of the skin. But there is lack of detailed studies on PV which indicates a need of continuing research on the current profile of this problem in our community. When compared to several studies in the past, few factors like age group, sex, distribution, predisposing factors, prevalence of itching, color of lesions and prevalence of seborrheic dermatitis are changing. This shows that we need to do further studies in larger sample to prove these findings. Besides as this disease is a recurring chronic problem finding the common predisposing factors in our setting and counseling the patients about them could decrease the recurrence of this disease.