<unk>  is rarely isolated from animals. In humans, men are more often infected than women. Infections can manifest as both chronic and acute forms. Typically T.<unk>  infections are restricted to the upper layers of the epidermis; however, deeper infections are possible. Approximately 80–93% of chronic dermatophyte infections in many parts of the developed world are thought to be caused by T.<unk>  including cases of tinea pedis(foot), tinea unguium(nail), tinea manuum(hand), tinea cruris(groin), and tinea corporis(arms and leg), as well as some cases of tinea barbae(beard).<unk>  has also been known to cause folliculitis in which case it is characterized by fungal element in follicles and foreign body giant cells in the dermis. A T.<unk>  infection may also form a granuloma. Extensive granuloma formations may occur in patients with immune deficiencies (e.g. Cushing syndrome). Immunodeficient neonates are susceptible to systemic T.<unk>  infection.<unk>  infections do not elicit strong inflammatory responses, as this agent suppresses cellular immune responses involving lymphocytes particularly T cells. Mannan, a component of the fungal cell wall, can also suppress immune responses, although the mechanism of action remains unknown.<unk>  infection has been associated with the induction of an id reaction in which an infection in one part of the body induces an immune response in the form of a sterile rash at a remote site. The most common clinical forms of T.<unk>  infection are described below. Foot<unk>  is one of the most common causes of chronic tinea pedis commonly known as athlete's foot. Chronic infections of tinea pedis result in moccasin foot, in which the entire foot forms white scaly patches and infections usually affect both feet. Individuals with tinea pedis are likely to have infection at multiple sites. Infections can be spontaneously cured or controlled by topical antifungal treatment. Although T.<unk>  tinea pedis in children is extremely rare, it has been reported in children as young as two years of age. Hand Tinea manuum is commonly caused by T.<unk>  and is characterized by unilateral infections of the palm of the hand. Groin Along with E. floccosum, T.<unk>  is the most common cause of this disease, also known as 'jock itch.' Infections cause reddish brown lesions mainly on the upper thighs and trunk, that are border by raised edge. Nail Once considered a rare causative agent, T.<unk>  is now the most common cause of invasive fungal nail disease (called onychomycosis or tinea unguium). Nail invasion by T.<unk>  tends to be restricted to the underside of the nail plate and is characterized by the formation of white plaques on the lunula that can spread to the entire nail. The nail often thickens and becomes brittle, turns brown or black. Infections by T.<unk>  are frequently chronic, remaining limited to the nails of only one or two digits for many years without progression. Spontaneous cure is rare. These infections are usually unresponsive to topical treatments and respond only to systemic therapy. Although it is most frequently seen in adults, T.<unk>  nail infections have been recorded in children.
Trichophyton rubrum
Epidermophyton floccosum
Microsporum fulvum
Microsporum gypseum
Malassezia furfur
Pythium insidiosum
Alternaria tenuissima
Trichobacteriosis axillaris