A clinicomycological study of tinea capitis in South Karnataka

Background: Tinea capitis is a superficial fungal infection in which scalp hair follicle are affected. It is most commonly seen among school going children. Now a days there is a drastic emergence of resistance to antifungal treatments and also we are observing changing trend in pattern and causing organism. Objectives: The present study was conducted to identify and classify the prevalent clinical pattern of tinea capitis in our region and to define the spectrum of dermatophyte species causing the tinea capitis in our region. Materials and Method: After taking informed written consent from the parents or the guardian, 100 new clinically diagnosed cases of tinea capitis were taken for the study over a period of 12 months from January 2015 to December 2015 in the Dermatology department, K.R Hospital, Mysore. Results: The incidence of tinea capitis among the total outpatients was 4.27%. The most common age group affected was 6-10 years. A male to female ratio was 1.7:1. The most common clinical type was grey patch type (61%) followed by black dot type (18%), seborrhoeic type (13%) and kerion (8%). KOH was positive in 85% cases and culture was positive in 43% of the cases. The organisms isolated were Microsporum gypseum in 19 cases (44.1%), Trichophyton violaceum in 17 cases (39.53%), Trichophyton rubrum in 5 cases (11.6%), Microsporum audouinii and Trichophyton tonsurans one case each. Conclusion: Tinea capitis is most commonly caused by Microsporum gypseum in our region. It will be very usefull do a direct microscopic examination and culture on every cases of tinea capitis, so that we can isolate the species and we can identify the any rare organism causing Tinea capitis. Keywords: Tinea capitis, Black dot, Grey patch, Trichophyton rubrum, Microsporum gypseum. Introduction Tinea capitis is the fungal infection of the scalp in which the essential feature will be invasion of hair shafts by a dermatophyte fungus usually. Tinea capitis is most commonly seen in children age group of 3 to 14 years. Tinea capitis can be transmitted via infected persons, their fallen infected hairs and some time through selected animal vectors. the incidence of T capitis varies from 0.5% to 10 % as seen by different. In USA Trichophyton tonsurans is currently the most common cause of tinea capitis I while Trichophyton violaceum has become a major cause of tinea capitis in Europe and also in india. Anthropophilic organisms Trichophyton tonsurans and Trichophyton violaceum are presumed to be associated with higher rates of asymptomatic carriage among children. This study was conducted to know the recent trends in the epidemiology and causative dermatophyte species of the disease as there are very few studies were conducted in the recent past. Materials and Method This study is a prospective cross-sectional, was conducted in the department of Dermatology, MMCRI, Mysore in collaboration with the Department of Microbiology. Total 100 new clinically diagnosed cases of tinea capitis were enrolled in the study over a period of 12 months from January 2015 to December 2015. A detailed history was taken and dermatological examination included clinical type of tinea capitis with areas of involvement on scalp, extent of involvement, screening of dermatophyte infection over other areas of skin & nails were done and noted. We also looked for Presence of regional lymphadenopathy. The siblings and other family members were also screened for tinea capitis and other dermatophytosis. The scalp scrapings were collected from the margins of the lesions with a sterile surgical blade, from at least two different areas of scalp. The affected dull and lustreless hairs were epilated with the help of a sterile epilators. All the specimens were collected in a clean sterile paper. Direct microscopic examination of the scrapings and hairs was carried out by mounting with 1-2 drops of 10%-20% KOH for 15-30 minutes. The remaining material was sent to the department of Microbiology where it was inoculated into Sabouraud dextrose agar (SDA) with chloramphenicol, cycloheximide and gentamycin and also selected culture in Dermatophyte test media (DTM). The microscopic characteristics of the culture material were studied using Lactophenol cotton blue mounts by both Microbiologist and Dermatologist. Results The incidence of tinea capitis in our study was 4.27% of our routine OPD. The majority of cases were Male childrens (63%) compared to females (37%). The male children to female ratio was 1.7:1. The predominantly involved age group was 6-10 years (56%) and the least in those more than 10 years Raju J et al. A clinicomycological study of tinea capitis in South Karnataka Indian Journal of Clinical and Experimental Dermatology, April-June 2017;3(2):60-63 61 (8%)[Table 1]. Incidence of tinea capitis was higher in children from rural back ground areas (53%) compared to 47% in the urban areas, though much difference was not observed. Majority of the cases (49%) belonged to lower socioeconomic status followed by lower middle class who contributed to 30% of the cases. Middle class contributed to 12% cases. In this study the number of cases residing in hostel was significantly lower (18%) than the non-hostel residents. Out of 18 residents of hostel, history of contact was present in 13 cases (72%), which is significant compared to 82 non-hostel residents, of which 9 only had history of contact (10.9%). In our study, the non-inflammatory type of tinea capitis (Table 2) was most czommon compared to inflammatory type. In the non-inflammatory type, grey patch variant was the most common type seen in 61% of the cases, followed by black dot type in 18% of the cases. Seborrhoeic type of T capitis was seen in 13% of the cases. In the inflammatory type, kerion was seen in 8% of the cases. (Fig. 1) Out of 100 cases subjected to wood’s lamp examination, only 3 cases showed green fluorescence, the cases belonged to grey patch type and showed ectothrix type of hair shaft involvement. Direct microscopy examination (Table 3) was done for all 100 cases, of which 85% were KOH positive and (Fig. 2) 15 were negative. In this study endothrix was seen in 54 cases and ectothrix was seen in 31 cases. Out of 100 cases in the study, 43 cases showed positive culture results. we compared both direct microscopy and culture results we found, 39% of the cases were both culture and KOH positive, 46% were KOH positive and culture negative, 11% were both KOH and culture negative and 4% were KOH negative and culture positive. Out of 43 culture positives (Table 4) Microsporum gypseum was isolated in 19 cases (44.1%) (Fig. 3, 4) and Trichophyton violaceum in 17 cases (39.53%). Trichophyton rubrum was isolated in 5 cases (11.6%) (Fig. 5) and Microsporum audouinii and Trichophyton tonsurans were isolated one case each. The major clinical pattern caused by Microsporum gypseum was grey patch type in 11 cases followed by kerion in 5 cases. Trichophyton violaceum caused black dot type in 8 cases, grey patch in 4 cases and seborrhoeic type in 5 cases. Trichophyton rubrum was seen in 4 cases of grey patch type and in 1 case of black dot type. Trichophyton tonsurans was seen in 1 case of grey patch type and Microsporum audouinii in 1 case of grey patch type. Table 1: Age and sex distribution