Thank you for your question.
The only way to diagnose and treat lesions on the genitals is to actually see them. There are several causes of blister like lesions. Some of them tend to be quite painful too. You say they are itchy but not painful. I would suggest you see a doctor specialising in skin and DVD. Also maybe worth checking if there are similar lesions in the mouth or elsewhere on the body. Sometimes your doctor can do a microscopic exam the same day and even a viral culture to detect the organism. Its a good idea to go while the lesions are still visible. Often the lesions heal up but return at a later date. Treating them in time can be beneficial.
hope this helps