Scanning electron microscopy of tinea nigra

Area of Science:

• Dermatology
• Mycology
• Microscopy

Background:

• Tinea nigra is a rare superficial fungal infection.
• It is caused by the fungus Hortaea werneckii.
• Characterized by asymptomatic brown to black maculae, primarily on the palms and soles.

Observation:

• Scanning electron microscopy (SEM) was utilized to examine a superficial skin scraping from a tinea nigra lesion.
• The outer surface revealed the epidermis with corneocytes and fungal hyphae, alongside the elimination of fungal filaments.
• The inner surface showed significant aggregation of hyphae among keratinocytes, forming small fungal colonies.

Findings:

• Ultrastructural findings from SEM correlated with dermoscopic observations.
• Small fungal aggregations observed via SEM may correspond to the dark spicules seen in dermoscopy.
• SEM documented the dissemination mechanism of tinea nigra, illustrating hyphal elimination on the lesion surface.

Implications:

• This study enhances understanding of tinea nigra's pathogenesis at a ultrastructural level.
• Findings may improve diagnostic accuracy by correlating microscopic and dermoscopic features.
• Understanding fungal dissemination provides insights for potential therapeutic strategies.