A lot of small rice bumps on the back may be a symptom of certain diseases, such as Malassezia folliculitis, acne, etc., and should be promptly consulted to identify the cause of the disease. 1. Malassezia folliculitis: mainly caused by Malassezia follicular inflammatory damage, occurring in sebaceous gland-rich areas, such as the back, chest, etc. Typical lesions for inflammatory follicular papules, small pustules, hemispherical, small in diameter, the number of generally more, can be surrounded by a red halo. 2. Acne: non-inflammatory papules formed as a result of blockage of follicular sebaceous gland ducts, often occurring on the back, face, etc. Its clinical manifestations are mainly conical papules consistent with the mouth of the hair follicle, yellowish-white or stippled black, accompanied by enlarged pores and sebum overflow. In addition, a lot of small rice bumps on the back may also be caused by other diseases, it is recommended that the patient promptly go to the regular hospital dermatology department, to be clear after the cause of the disease, the appropriate treatment.