Rhinoscleroma is caused by:

(a) Klebsiella(Ref. Scott Brown, 8th ed., Vol 1; 1212)Rhinoscleroma is a bacterial granuloma caused by Klebsiella rhinoscleromatis also known as Frisch bacillus.Rhinosporidium seeberi, an aquatic protistan protozoa (unicellular) parasite, causes a granulomatous condition called rhinosporidiosis.Spirochete (syphilis) and autoimmune conditions (e.g. Wegener's granulomatosis) are the other nasal granulomatous conditions.