The sudden growth of many small rice-grain bumps on the face is a condition that could be whitehead acne. The symptoms are small bumps that resemble grains of rice, which are usually the type of acne. It is a type of acne vulgaris, which occurs mainly when the follicle sebaceous gland opening is blocked, or when the local sebaceous glands are unable to excrete effectively due to excessive secretion, and then concentrates into lipid plugs, which accumulate on the surface of the ducts of the follicle sebaceous gland opening, so that it is observed as a whiteheaded pimple, or like a grain of small fatty grains.