A layer of small bumps on the face without pain or itching may be folliculitis, allergic dermatitis, acne and other diseases. 1. Folliculitis: is due to bacteria, fungi and other pathogens caused by hair follicle infection leads to hair follicles and the surrounding purulent dermatosis, manifested in the formation of red pimples around the hair follicles, a layer of small pimples on the face without pain and itching may be caused by folliculitis. 2. Allergic dermatitis: it is a disease of itchy skin, pimples and other symptoms caused by allergic substances, a layer of small bumps on the face without pain and itching may be caused by allergic dermatitis. 3. Acne: a chronic inflammatory disease caused by blockage of the sebaceous glands of hair follicles, characterized by polymorphic skin lesions such as pimples, papules, pustules, and nodules that develop on the face. A layer of small bumps on the face does not hurt or itch may also be seen in other diseases, if the persistence of non-relief, it is recommended that patients seek medical attention in a timely manner, a clear diagnosis, standardized treatment under the guidance of the doctor.