Integumentary
Image Set 33 - Ectothrix hair (KI stain)
Dermatophyte infection of hair produces one of three patterns of fungal invasion:
ectothrix, endothrix, or favic depending on the species of dermatophyte.

Ectothrix pattern: arthroconidia form on the outside of the hair.
Endothrix pattern: arthroconidia form inside the hair.
Favic pattern: a "honeycomb" pattern of hyphae, arthroconidia, and empty spaces resembling air bubbles form inside the hair.
Mycology Online
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