Dirt inside the foreskin, commonly found in patients with a long prepuce, is mainly caused by the accumulation of lipid secretions of the inner plate of the prepuce inside the foreskin, and daily cleaning is recommended to prevent inflammation of the foreskin. When the patient’s foreskin is too long, due to the strong secretion function of the inner plate of the foreskin, some lipid secretions usually increase, if the patient can’t clean up these secretions in time, they accumulate in the cavity of the foreskin, and over time, they will form foreskin scale. Can produce stimulation of the foreskin, glans mucosa, often cause penile itching, inflammation, etc.. It is recommended that patients develop the habit of circumcision cleaning, the foreskin upturned, completely exposed the glans as well as the coronal groove, warm water cleaning, to maintain local cleanliness, can effectively prevent the formation of circumcision and glansitis. The dirt inside the foreskin is mainly due to the accumulation of lipid secretions, it is recommended to wash in time, if there are uncomfortable symptoms timely consultation.