Onychomycosis is most commonly caused by -

Ans. is 'a' i.e., Trichophyton rubrum Tinea Unguium (Onychomycosis)o Tinea unguium is dermatophvtic infection of fingers and toe nails. Most common causative species is T-rubrum. Toe nails are more commonly involved. T. Unguium may be of two types : -Distal subungal onychomycosis : - This is most common type offungal infection of nail (90%). It starts at the distal edge of the nail plate and slowly growrs inwards to involve entire nail plate.Proximal Subungal onychomycosis : - Starts at the base of nail and slowly involves the entire nail plate.