Wheat grain bumps under the penis may be caused by penile pearly papules, condyloma acuminatum, folliculitis and other factors. 1. Penile pearly papules: may be related to poor hygiene, friction, belong to a benign lesion, will make the local skin color pimples, usually no conscious symptoms, and will not endanger the health of the reproductive system, usually can not be treated, regular review can be. 2. Condyloma acuminatum: usually caused by human papilloma virus infection, mostly transmitted through sexual contact, will lead to localized penile pimples, and accompanied by mild itching and tingling, and has a strong contagious. 3. Folliculitis: men do not often wash the penis area, may induce folliculitis, infection aggravation will make the local appearance of small pustules, may also be accompanied by itching and tingling. The reason for the wheat pimples under the penis is many, it is recommended that men go to the urology department of the hospital for appropriate examination and treatment.