The interplay among Th17 and T regulatory cells in the immune dysregulation of chronic dermatophytic infection.

The delineation of the pathogenic interaction between the host skin immune responses and dermatophytes has remained indigent. The obscure enigma in host-dermatophyte immunopathogenic interactions is the T regulatory (Treg) and T-helper (Th) 17  cell role in maintaining immune homeostasis. We attempted to understand the regulation and recognition of lineage-specific response in chronic dermatophytic skin infection patients. The percentages of Th17 (CD4+CD161+IL23R+) and Treg (CD4+CD25+FoxP3+) cell subpopulations in the peripheral circulation of thirty chronic dermatophytic skin infection patients and twenty healthy individuals was determined. The serum cytokine levels were estimated for disease correlation. The mean duration of the disease was 10.68 ± 8.72 months, with Trichophyton mentagrophytes complex as the major pathogen. Total serum IgE level of patients was significantly higher compared to healthy controls (305 ± 117 vs 98.53 ± 54.55 IU/ml; p < 0.01). Expression of Th17 and Treg cell markers on CD4+ T cells was significantly elevated in patients than controls (p < 0.05). Comparatively, serum interleukin (IL)-4 and interferon (IFN)-γ levels were increased, with low IL-10 levels in patients. Our data envisages a complex immune dysfunction in chronic dermatophytosis, arising either as a result of dermatophyte exposure or paradoxical precedence of disease establishment. Designing new treatment strategies and preventing recurrences are challenges for future research.

Burden of Chronic Dermatophytosis in a Tertiary Care Hospital: Interaction of Fungal Virulence and Host Immunity.

Dermatophytosis is caused by keratinophilic dermatophytes and affects the superficial skin and its appendages. The nature of infection and response to treatment is influenced by host-pathogen factors like duration and severity of disease, prior drug history and type of causative organism. In our study, the burden of dermatophytosis affecting glabrous skin saw a rise in recalcitrant and reinfection cases with only 1.6% achieving complete cure. Chronicity of dermatophytic infection was reflected in the high serum IgE levels and immediate hypersensitivity reactions. Hence, it becomes pertinent for clinicians to identify the non-responders and modify therapy to achieve clinical cure with fungal clearance confirmed by mycological tools.