It looks like a mere pimple ...a simple infection under the skin just as you may get any other area ..
I would start with applying Neosporin cream twice a day and watch this ....
I expect that it will clear up over the course of a week...
The appearance and your history do not suggest an STD ..
I would have more concern if it expanded or you had multiple bumps appear or blisters developed ..
I think it will clear within about 1 week time frame ..
I hope that this information is helpful for you
Let me know if you have further questions or concerns
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Thank you and Best Regards,
Anthony Bray MD