The infection is related to a variety of circumstances. 1. to consider is the environmental factors, the summer temperature is high, the skin is prone to sweating, conducive to the growth of spores. 2. to consider is the drug factors, long-term use of antibiotics or glucocorticoids, as well as immunosuppressants, easy to lead to dysbiosis and immune deficiency, but also to the conditions created by the infection of spores. 3, Also consider with the skin barrier function is impaired, certain skin diseases, such as eczema, atopic dermatitis, etc., resulting in abnormal skin barrier function, easy to infect spores of furfur. There are also certain systemic diseases, such as diabetes, AIDS, etc., can also lead to infection. 4, may also be related to lifestyle factors, usually no attention to skin cleanliness and hygiene, but also easy to breed spores of furfur.