Onychocola canadensis

Teleomorph: Arachnomyces nodososetosus Sigler & Abbott

Colonies grow slowly and are velvety to lanose, white to yellowish, with a brownish reverse. Arthroconidia are cylindrical to broadly ellipsoidal, one- or two-celled, hyaline to subhyaline, 4-16 x 2-5 µm in size, forming long chains. Older cultures may show broad, brown, rough-walled hyphae. RG-2 organism.

Culture and arthroconidia of Onychocola canadensis.

Key Features: slow growing, white, arthroconidial mould isolated from nails.

Clinical significance:

Onychocola canadensis is an uncommon cause of distal and lateral subungual or white superficial onychomycosis. However, it may sometimes be present in an abnormal-appearing nail as an insignificant finding, not acting as a pathogen.

Mycosis: Hyalohyphomycosis

Further reading:

Domsch, K.H., W. Gams, and T.H. Anderson. 1980. Compendium of soil fungi. Volume 1. Academic Press, London, UK.

Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA.