Studies on invasive keratinophilic Dermatophytes of human hair

Abstract

Background: Tinea Capitis (TC) is a dermatophyte infection of the scalp hair follicles and intervening skin. TC is mainly caused by anthropohilic and zoophilic species of the genera Trichophyton and Microsporum. On the basis of the type of hair invasion, dermatophytes are also classified as endothrix, ectothrix or favus. Despite the availability of effective antifungal agents, dermatophytic infections continue to be one of the principal dermatological diseases in Mysore. Objectives: To study the genus and species variants, of fungus causing Tinea Capitis infection and epidemiological factors responsible for the disease in Central Mysore. Materials and methods: Clinically suspected 527 patients with dermatophytes infection cases were included in our study, where 58 cases were diagnosed and confirmed as a Tinea Capitis patients only selected for our study. Suspected lesion like scalp skin scraping and hair plucking samples were collected after disinfecting the site with 70% of ethyl alcohol. Samples were collected in a sterile thick black envelope, folded, labelled and brought to the laboratory for further processing according to slandered Mycological protocol. Results: A total of 527 patients with dermatophytes infection suspected cases were included in our study, where 58 cases (11.0%) were confirmed as a Tinea Capitis. Majority of the dermatophytic infections were seen between April to October i.e. 51, 63, 52, 30, 51, 60 and 57 respectively, so this signified that hot and humid climate favour for dermatophytic infection. There was 33 cases of endothrix infection and only 12 cases of ectothrix infection and 13 cases were not ascertained but P value is significant (P< 0.001) Among all dermatophytes Tinea Capitis was mainly caused by only one genus i.e. T. tonsurans 29/58 (34.4%), T. violaceum 8/58 (31.0%), T. verrucosum 4/58 (6.8%) and T. mentagrophytes 8/58 (13.7%) were isolated. Conclusion: The prevalence of dermatophyte infections among children was (11.0%), which is most common among the other clinical type of infection. Poverty, lower socioeconomic status, unhygienic condition, hot humid climate and young age group child is the major factors which intensify the dermatophyte infection as a cause of Tinea Capitis. There for continuous isolation identification and conformation of dermatophyte is essential to treat with antifungal drugs for their complete cure.

Suitability of hair type for dermatophytes perforation and differential diagnosis of T. mentagrophytes from T. verrucosum

“…It usually helps other diagnostic methods for differentiation between the closed related species of dermatophyte such as the differentiation between T. mentagrophytes and T. rubrum , when T. mentagrophytes gives a positive result of hair perforating in comparing with a negative result of T. rubrum . All of known references recorded that there is no difference in the perforation ability of T. mentagrophytes , which formed endothrix spores in the hair and T. verrucosum that formed ectothrix spore . The present results of our research revealed that the type of hair source could play an important role in differentiating between T. mentagrophytes and T. verrucousum .…”

“…They have the ability to degrade the keratin containing materials such as skin, hair, nail, feather and fur by secretion of keratinase enzyme . In most infected hair of human or animals, dermatophytes can produce asexual spores either on the outer layers of the hair calling ectothrix or in the hair as endothrix . Some of dermatophyte species prefers the hair of human than animal in order to obtain keratin protein with a variable degradation rate as relating to the type of hair source .…”