<prompt> Dermatophytes areTinea versicolorTrichophyton rubrumSporothrixAll of the above  <response>: Ans: b Trichophyton rubrumRef: Harrison 17th ed. 1309DERMATOPHYTOSIS OR RING WORM TINEA INFECTION Dermatophytes include a group of fungi ring worm that under most conditions have the ability to infect survive only on dead keratin; that is the superficial topmost layer of skin stratum corneum or keratin layer, hair and nails. They cannot survive on mucosal surfaces eg mouth or vagina where the keratin layer does not form. The ring worm fungi belongs to 3 genera:TrichophytonMicrosporumEpidermophyton Infects skin, hair nail Infecting species include: Trichophyton rubrum Mentagrophyte Violaceum Verrucosum Schoenleinii Infects skin and hair but does not involve nails Several infecting species include: Microsporum audounii, M. gypseum and M. canisInfect skin nails but does not involve hair Only infecting species is Epidermophyton floccosum.Mnemonic TSH-N Trichophyton infects Skin, Hair and Nail MSH Microsporum infects Skin and Hair ESN Epidermophyton infects Skin and Nail 