case_images: PMC11750295_01
case_images: Clinical features. a: A 7 x 5 cm hair loss lesion with purulent discharge and crusts on the occiput, with some areas showing black dots. b: Scales were observed on both auricles.c: Symmetrical pruritic erythematous papules were observed on the chest and both forearms.
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case_images: PMC11750295_01_gr1.jpg
case_images: fig1
case_images: However, KOH microscopy of these lesions revealed no fungal elements (Fig. 1).
case_images: Histopathological findings. a: Infiltration of neutrophil-predominant inflammatory cells was observed around the dermal hair follicle. While the structure of the dermal hair follicle was preserved, the epidermal side was replaced by a pustule containing a transverse section of the affected hair (arrow) (HE, x 100). b: Magnified view of the transverse section of the infected hair. Fungal hypha-like structures are observed in the hair shaft (HE, x 400). c: Fungal elements stained black with Grocott stain were observed in the hair shaft, and endothrix infection is confirmed in the transverse section (GMS, x 400).
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case_images: PMC11750295_01_gr2.jpg
case_images: fig2
case_images: Fungal hyphae were identified within the hair shafts using hematoxylin and eosin (HE) staining and Grocott's methenamine silver (GMS) staining, confirming endothrix invasion with large spore formation (day 5) (Fig. 2).
case_images: Fungal Culture. a: A fungal culture was performed by scraping the patient's scalp with a hairbrush. This image shows the reverse side of the medium after 12 days of incubation at room temperature. Various colony morphologies were observed, but colonies with a reddish-brown reverse (indicated by the arrow) were selected and subcultured. b: Subcultured colony from "Fig. 3-a". After 20 days of incubation at room temperature on Sabouraud agar medium, the colony surface exhibited a white, cotton-like texture. c: The reverse side of the isolated colony exhibited reddish-brown pigmentation.
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case_images: PMC11750295_01_gr3.jpg
case_images: fig3
case_images: A colony with a white powdery surface and reddish-brown reverse side was isolated and further cultured (day +20) (Fig. 3).