Acne around the neck can be caused by folliculitis, boils, atopic dermatitis and other diseases. 1. Folliculitis: Folliculitis is mainly caused by pathogen infection, followed by skin trauma, wearing tight clothes and rubbing the skin can also stimulate the hair follicles to trigger folliculitis, manifested as red pimples centered on the hair follicles, which can appear around the neck. 2. Boils: acne around the neck can also be boils, boils are mostly caused by Staphylococcus aureus infections, the affected area will appear slightly elevated red painful nodules, about the size of a pea. Most of them can turn into pus and burst on their own, and the inflammation will gradually subside and heal after the pus flows out. 3. Atopic dermatitis: the causes of atopic dermatitis are mostly related to genetics, immune abnormalities, environmental factors, etc. It manifests itself as dry skin, eczema-like rashes, and intense itching, etc., and it is common in the hands, feet, and neck. There are more causes of acne around the neck (e.g. acne, etc.), and it is necessary to consult a doctor for examination and clear diagnosis, and do not self-medication.