Histopathology of hair follicle epithelium in patients of recurrent and recalcitrant dermatophytosis: A diagnostic cross-sectional study

Abstract

Context: Recurrent and recalcitrant dermatophytosis is a major evolving health problem in India. Histopathology is important in the diagnosis of recurrent and resistant cases, as it is postulated that hair follicle epithelium is affected, acting as the reservoir leading to recurrence and recalcitrance. Aims: This study aims to study histopathology of hair follicle epithelium in patients of recurrent and recalcitrant dermatophytosis. Settings and Design: A diagnostic cross-sectional study was performed at tertiary care hospital and referral center in central India. Materials and Methods: A 3 mm-sized punch skin biopsy was taken from 108 patients of recurrent or recalcitrant dermatophytosis involving hair follicles. Sections were stained by hematoxylin and eosin (H and E) stain in these patients followed by special stains such as periodic acid–Schiff (PAS) stain and Gomori methenamine silver (GMS) stain in 78 individuals where hair follicle was seen on H and E stain. Results: In H and E stain, surface epidermis fungus was observed in 57/108 patients (52.7%). In hair follicle-positive sections (78), surface fungus was seen in 52.6% with H and E stain, 84.6% with PAS stain, and 91% with GMS stain. H and E was 62.12% sensitive and 100% specific to diagnose fungus when compared with PAS stain and 57.7% sensitive and 100% specific when compared with GMS stain. PAS was 91.5% sensitive and 85.7% specific when compared with GMS stain. Ectothrix infection was the most common form of hair infection observed in 87.2% cases with GMS stain. Simultaneous presence of fungus in hair follicle and stratum corneum was observed in 87.3% of patients. Conclusion: Majority of patients showed affection of hair follicles by dermatophytes in clinically chronic, recurrent, and recalcitrant dermatophytic infections. GMS stain is the acceptable gold standard for detection of fungal elements.

Diagnosis and treatment of dermatophytic furunculosis in a polar bear (Ursus maritimus)

“…3 Detection of fungal hyphae is not always possible with haematoxylin and eosin staining, and as in the reported case, periodic acid-Schiff or Grocott methenamine silver are often used to aid in visualisation. 7 Dermatophytosis has been described in a small number of bears in the literature. 8,9 M. gypseum was diagnosed in a pet bear (species unknown) and successfully treated with topical iodine.…”

“…Dermatophytes have been visualised in deep infections in cases of feline mycetoma, 4 feline 5 and canine 6 pseudomycetoma and dermatophytic furunculsis 3 . Detection of fungal hyphae is not always possible with haematoxylin and eosin staining, and as in the reported case, periodic acid–Schiff or Grocott methenamine silver are often used to aid in visualisation 7 …”

A Clinico-Mycological and Histopathological Study of Recurrent Dermatophytosis

“…[ 10 ] A few recent studies have postulated that presence of fungal hyphae in hair follicle could serve as a reservoir and enable clinical resistance, recurrence, and chronicity resulting in chronic and recurrent dermatophytosis. [ 6 7 ]…”

“…Study of histopathology is becoming increasingly important in the assessment of recurrent dermatophytosis in view of the findings of a few recent studies that have shown the presence of fungal elements within the hair follicle unit or epithelium. [ 6 7 ] These fungal elements act as a reservoir, leading to recurrence and recalcitrance of dermatophytosis. Dermatophytic infection of vellus hair in sites other than the scalp, may also give rise to recurrence.…”

A case of dermatophyte abscess and adjunctive use of a novel RNA: In situ hybridization to confirm Trichophyton rubrum

“…Histologic identification of fungal elements remains difficult. 1 Special stains like Grocott-methenamine silver and periodic acid–Schiff increase the detection 2 but the gold standard remains culture and morphologic identification of the fungi itself. 1 In situ hybridization (ISH) is a method being used for fungal identification and as such, refinements on the technique have been developing.…”