Dermatophytosis is a fungal infection affecting keratinized areas of the body (stratum corneum of the epidermis, hair or nails). In fact, dermatophytes settle in areas rich in dead keratin material, which they eat.
Unlike candidiasis, dermatophytosis in general is not an invasive infection. They can be caused by fungi belonging to the genera Epidermophyton, Microsporum or Trichophyton spp . and, based on the site of the infection, they are divided into
- tinea corporis,
- tinea cruris (or inguinal ringworm)
- tinea pedis (or athlete's foot)
- tinea unguium (onychomycosis)
- tinea capitis
- tinea barbae.
The transmission can take place from person to person, from animal (cat, dog, rabbit, mouse and cattle) per person or, more rarely, from the ground to the person. Predispose to dermatophytosis the conditions of immunosuppression (eg patients with diabetes) or reduction of local defenses (eg trauma with vascular compromise).
Most common symptoms and signs *
- Pus formation
- Leg itch
- Itching in the hands
- Itching in the head
- Scales on the skin
- Skin Ulcers
- Coarse and opaque nails
The symptoms of dermatophytosis vary depending on the site of infection (skin, hair or nails).
Dermatophytosis may not be clinically evident or cause inflammation (more or less severe) on the surface of the skin. Most often, inflammation is mild and associated with the intermittent appearance of asymptomatic or little pruritic lesions. In the most serious cases, on the other hand, inflammation manifests itself with blisters and sudden onset fissures (this happens especially at the level of the feet).
Sometimes, dermatophyte infections determine the formation of a kerion, that is a large soft inflammatory lesion that determines areas of alopecia.
Tinea barbae is a dermatophyte infection of the beard region; occurs with superficial annular lesions or with an inflammatory kerion, but signs similar to those of folliculitis may also appear.
Tinea capitis affects the scalp; causes the gradual appearance of round patches associated with dry scaling and / or alopecia. Some dermatophytes cause a gray or black ringworm, depending on whether the hair breaks above (leaving small roots) or at the level of the surface of the scalp (where the spots appear dotted). Less commonly, tinea capitis manifests itself as a diffuse desquamation, similar to dandruff, or with a pustular appearance. If the inflammatory reaction towards the dermatophyte is very serious it can cause the formation of a kerion, which, in case of scarring, can cause hair loss.
Tinea corporis is an infection of the face, trunk and limbs. This dermatophytosis is characterized by the appearance of pink-red annular patches with flaky, slightly raised edges, which expand peripherally and tend to lighten centrally.
Tinea cruris is an inguinal dermatophyte infection particularly favored by hot weather, apposition of skin folds (especially in obese subjects), damp and tight clothing. Generally, it causes an itchy and annular lesion that can become complicated with maceration and secondary bacterial or candida infections. Furthermore, scratching and lichenisation dermatitis can occur.
Finally, tinea pedis is dermatophytosis of the feet; it is the most common infection. Narrow shoes, heat and humidity in the area facilitate the proliferation of fungi. Tinea pedis produces lesions that manifest as scaling, plantar thickening, redness, itching and a burning sensation between the toes. In addition, blisters, ulcers and fissures may appear.
The diagnosis of dermatophytosis is based on the clinical aspect and is confirmed by the examination of cutaneous scarifications (they show the presence of the hyphae). Culture testing is generally not necessary, except for serious nail infections (the causative agent may not be a dermatophyte) and scalp (to exclude other diseases that cause alopecia).
The treatment involves the use of topical or oral antifungal drugs. Sometimes, corticosteroids can be used to help relieve itching and pain caused by severe inflammatory lesions.