Pimples on the neck, known as acne, may be related to excessive sebum secretion, abnormal keratinization of hair follicle openings, and Propionibacterium acnes infections, with consumption of spicy, irritating, oily foods and lack of attention to cleansing as triggers. 1. Excessive sebum secretion and abnormal keratinization of follicle openings. Excessive sebum secretion and abnormal keratinization of hair follicle openings in the neck can lead to oil clogging, resulting in acne. 2. Propionibacterium acnes infection. Under the influence of the above sebaceous gland secretion factors, when the neck is infected with Propionibacterium acnes infection, due to inflammation stimulation can aggravate acne. 3. Bad dietary habits. Frequent consumption of spicy stimulation, greasy food, high sugar food, will stimulate the sebaceous gland secretion; commonly used oily cosmetics and so on also belong to the triggering factors of acne. When neck acne is not relieved for a long time, you should seek medical treatment in time, and actively treat it under the guidance of the doctor.