Thank you for your question.
There are several conditions that can cause sores on the penis. Genital herpes simplex is the most common. Herpes can form bumps rather than blisters. It can be confirmed by doing a stain of a swab of the lesion or herpes culture. Blood tests to look for antibodies to herpes can also be done. There are other STDs that can cause sores on the penis, including syphilis and chancroid. There are other causes of bumps on the penis, such as molluscum contagiosum or folliculitis. Since herpes is the most likely, the first step is to confirm whether it is herpes.