On Sabouraud's dextrose agar, colonies are slow growing, waxy or suede-like with a deeply folded honey-comb-like thallus and some sub-surface growth. The thallus is cream coloured to yellow to orange brown. Cultures are difficult to maintain in their typical convoluted form, and rapidly become flat and downy. No reverse pigmentation is present. No macroconidia and microconidia are seen in routine cultures, however numerous chlamydoconidia may be present in older cultures. However, characteristic antler "nail head" hyphae also known as "favic chandeliers" may be observed. A few distorted clavate microconidia may be formed by some isolates when grown on polished rice grains. RG-2 organism.
Culture of Trichophyton schoenleinii.
"Favic chandeliers" of T. schoenlenii.
Trichophyton schoenleinii is an anthropophilic fungus causing favus in humans. Favus is a chronic, scarring form of tinea capitis characterized by saucer-shaped crusted lesions or scutula and permanent hair loss. Invaded hairs remain intact and fluoresce a pale greenish yellow under Wood's ultra-violet light. Favus is common in Eurasia and Africa.
Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA.
Rebell, G., and D. Taplin. 1970. The Dermatophytes. 2nd. revised edition. University of Miami Press, Coral Gables, Florida. USA.