in humans and domestic animals, a disease caused by any fungus that invades the tissues, causing superficial, subcutaneous, or systemic disease. Superficial fungal infections, also called dermatophytosis, are confined to the skin and are caused by Microsporum, Trichophyton, or Epidermophyton; athlete's foot, for example, is caused by Trichophyton or Epidermophyton. Subcutaneous infections, which extend into tissues and sometimes into adjacent structures such as bone and organs, are rare and often chronic. candidiasis (Candida) may be a superficial infection (thrush, vaginitis) or a disseminated infection affecting certain target organs, such as the eyes or kidneys. Painful ulcerations and nodules appear in subcutaneous tissues in sporotrichosis (Sporothrix). In systemic fungal infections fungi may invade normal hosts or immunosuppressed hosts (opportunistic infections). Cryptococcosis (Cryptococcus) and histoplasmosis (Histoplasma) are marked by respiratory distress.

Effective therapy against the invasive fungi is limited because the same antibiotics that interfere with fungi also attack the host's cells. Griseofulvin has met with some success in the treatment of superficial mycoses. Amphotericin B and flucytosine have also been used in treating the subcutaneous and systemic mycoses.