Thank you for the input.
Redness of penis with a little swelling can be from inflammation or infection of the skin of the penis.
It can be due to a bacterial or fungal infection.Allergy
to soap, lotion can cause it.
You can wash the area with saline water
Neosporin cream can be used after cleaning the area.
In mild cases, it would subside with those measures.
If you notice the swelling, redness is increasing, I would advise to take an examination by doctor.
I hope this information will be helpful.
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Wish his healthy life.