Fungal Skin Infections are caused by an excessive growth of fungus on the skin's surface, affecting the skin, hair or nails. Common fungal infections include ringworm, tinea versicolor, jock itch, male yeast infection and intertrigo, or skin fold rash. Symptoms vary per condition but may include itchy, scaly red rash, discoloration and inflammation. Humid climates or stress may trigger an overgrowth of yeast, leading to a fungal skin infection. Other contributing factors include obesity, weakened immune system and wearing tight-fitting clothing. It is also possible to contract a fungal infection, such as ringworm, by coming into contact with someone who has an infection, as they may be contagious. To help avoid fungal infection, keep skin clean and dry, and avoid sharing towels, hairbrushes and combs.