Small red pimples on the face are considered to be caused by acne, folliculitis, urticaria and other factors. 1. Acne: If the patient’s body androgen level is elevated, it will stimulate the sebaceous glands to secrete a large amount of oil, when the oil and the shed epidermis at the same time block the pores, it will form an inflammatory reaction in the local area, which will lead to the symptom of small red pimples on the face. 2. Folliculitis: If the face is not cleaned properly, it will lead to the growth of local bacteria, which will stimulate single or multiple hair follicles, triggering an inflammatory reaction, so that the patient will have the symptom of small red pimples on the face, accompanied by itching, pain and other symptoms. 3. Urticaria: If the patient belongs to the allergic body, the face in contact with pollen, animal hair, dust and other allergic substances, will make the local vascular permeability increase, thus triggering the symptoms of small red pimples on the face, accompanied by different degrees of itching. When the appearance of small red pimples on the face, it is recommended that early treatment to minimize the adverse effects of the disease.