There are many conditions that can cause penile lesions; many of these can or should be treated, and it is therefore very important that you go see your doctor
so they can take a look and recommend treatment.
There are several conditions that classically cause itching. Lichen simplex chronicus occurs with persistent rubbing or scratching, often after an itch, and leads to thickening and persistent itching, often of the scrotum. This can be treated with antihistamines. Scabies can infect the penis and cause itchy nodules or blisters on the penis; this would often be accompanied by itching elsewhere, and needs to be diagnosed under the microscope. Molluscum contagiosum is a viral infection that can cause dome-shaped bumps and often has some itching. An inflammatory condition of the penis called Zoon's balanitis can also cause itching and often red or oozing patches on the penis.
There are also many other conditions that can cause lesions on the penis that may be irritating and making you itch. If you are sexually active, you are at risk for sexually transmitted diseases, including genital warts
(HPV infection), and could be spreading these to other people. For these reasons I strongly recommend you go see your doctor. It can be uncomfortable to go see a doctor with this problem, but physicians see these kinds of lesions all the time, and they can help you find a diagnosis and very likely give you treatment to make your itch feel better.