The cause of acne on the neck, clinically, is mainly due to the patient's low immune function, or the local sanitation is not ideal, resulting in local hair follicles or local sebaceous glands to produce inflammatory reactions. Generally, it may be that the patient often stays up late, or due to improper extrusion, etc., local hair follicular papules may occur. Of course, it may also be that the patient improperly uses glucocorticoid drugs, which eventually induces fungal infection, such as malassezia folliculitis caused by malassezia infection.