Brief Answer:
Might be a sebaceous cyst; also chances of viral warts

Detailed Answer:
Hi,
Thank you for posting your query in healthcaremagic.com
This is Dr. Swarnava dattagupta answering your query.

I have gone through your query and understand your concern.
You have given a very short history of your red hard swelling over scrotal skin. I would like to know a few things like since when it is present, any pain or discharge from it, the size of it, any sexual exposure.
It would be also very helpful if you can post a picture of the swelling so that I can tell you further.
However, it can be a sebaceous cyst or a viral wart which are common swellings in this location. Chances of wart is more if there is history of sexual exposure. If it has got no symptoms, dont worry as of now. If it grows gradually, a Surgeon can be consulted to rule out other pathology.
Get back to me with a picture of the swelling.

Hope i have answered your question.
If you have any further questions i will be happy to help.
Regards

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