The main causes of buttocks with granular roughness include keratosis pilaris, eczema, warts, folliculitis and so on. 1. Keratosis pilaris: due to various factors triggering the appearance of keratinized pimples at the mouth of the hair follicle, then the phenomenon of roughness of the buttocks with granularity can occur. 2. Eczema: acute stage is mainly manifested as local erythema, visible pinpoint or cornucopia of rashes, touch will have a granular feeling. 3. warts: due to human papilloma virus infection of the human body, these viruses can trigger the skin proliferation, mostly manifested as a rough surface, hard, soybean size or larger keratinized pimples, touching the buttocks skin will be conscious of the skin roughness, there is a granular sensation. 4. Folliculitis: If the hair follicle is infected by bacteria, then there can be a rash, then there will also be rough particles on the buttocks phenomenon. Finally, the phenomenon of roughness in the buttocks with granularity, please consult a doctor in time to find out the cause and follow the doctor’s instructions for treatment.