Hard pimples on the foreskin are mostly seen in pearl rash, circumcision, warts and so on. 1. Pearl rash: mainly occurs in the coronal edge of the penis as well as the coronal groove, there may also be a small number of appearances on the foreskin, often and local stimulation and physiological developmental variations, most of them do not have obvious symptoms of discomfort. 2. circumcision: it is due to inflammation caused by traumatic stimulation or infection of the glans area, which may lead to small pimples on the foreskin, accompanied by itching, pain and other symptoms. 3. Condyloma acuminatum: a sexually transmitted disease caused by human papilloma virus infection, easy to appear in the external genital skin mucosa, men usually appear in the glans, the coronal groove, the foreskin and so on above, most of the small reddish particles, the texture is soft, with the progression of the disease, it may be formed in the form of cauliflower-like, papillary. Hard pimples on the foreskin may also be caused by other reasons, it is recommended to go to the hospital in time.