Dermatophytosis
Also called tinea or ringworm, dermatophytosis is a disease that can affect the scalp (tinea capitis), body (tinea corporis), nails (tinea unguium), feet (tinea pedis), groin (tinea cruris), and bearded skin (tinea barbae).
Tinea infections are quite prevalent in the United States and are usually more common in males than in females. With effective treatment, the cure rate is very high, although about 20% of persons with infected feet or nails develop chronic conditions.
Causes
Tinea infections (except for tinea versicolor) result from dermatophytes (noncandidal fungi) of the genera Trichophyton, Microsporum, and Epidermophyton that involve the stratum corneum, nails or hair.
Transmission can occur directly (through contact with infected lesions) or indirectly (through contact with contaminated articles, such as shoes, towels, or shower stalls). Some cases come from animals or soil.
Signs and symptoms
Lesions vary in appearance and duration with the type of infection:
Tinea capitis, which mainly affects children, is characterized by round erythematous patches on the scalp, causing hair loss with scaling. In some children, a hypersensitivity reaction develops, leading to boggy, inflamed, commonly pus-filled lesions (kerions).
Tinea corporis produces flat lesions on the skin at any site except the scalp, bearded skin, groin, palms, or soles. These lesions may be dry and scaly or moist and crusty; as they enlarge, their centers heal, causing the classic ring-shaped appearance.
