A lot of small pimples on the face may be caused by acne, or it may be caused by many diseases that manifest as pimples, such as folliculitis, cornuosis, and other diseases. 1. Acne: Acne may be triggered by poor dietary habits, increased secretion of sebaceous glands, bacterial infections and other factors. Symptoms such as pimples, comedones, pustules, and cysts in areas with dense sebaceous glands such as the cheeks, forehead, or jaw may cause a lot of small pimples on the face. 2. Folliculitis: caused by bacterial or fungal infections, friction of external substances leading to hair follicle damage, the body’s immune system decline and other factors. The manifestation of a single, multiple or groups of red papules centered on hair follicles, sometimes with pustules at the top. There may be a lot of small pimples on the face. 3. Corns: related to heredity or damaged sweat ducts, manifested as firm pimples the size of corn grains, usually does not affect the health. If you have a lot of small pimples on your face, it is recommended that you go to the hospital and under the guidance of your doctor, have a relevant examination to clarify the cause of the disease.