###Human: I was masturbating and noticed soreness under head of penis. What is it? ###Assistant: Hi. I have been through your case in detail. Well in short as you know there are two possibilities:  1. Friction erosion. 2. It could be herpes infection. Herpes 2 usually on genitalia and herpes 1 on lips. As now there is no limitation in having herpes 1 on genitalia due to common oral sex. So in my opinion, you may have it as blistering is not the only presentation, superficial erosions also represent herpes. So it is always better to keep pathology of herpes in mind rather rely only on the frictional blister. For management, do the following: All treatment for seven days. For more information consult a dermatologist online -->