There are more causes of fungal skin infections, and there are about 300 types of pathogenic fungi. Causes of fungal infections include the following: 1. Causes of the body: Fungal infections can be caused by a lowered immunity of the body; 2. Infectiousness: Common fungal infections include ringworm, ringworm of the hands, ringworm of the feet, ringworm of the nails, ringworm of the femur, ringworm of the body, such as infection of foot, which is a shallow fungal infection. Infections are caused by people infecting each other, such as wearing other people’s slippers or socks in public places, or using common things with each other between couples or families can be infectious. Ringworm can also be transmitted by shaking hands, or ringworm or ringworm can be transmitted by touching shared items.