Thanks for the query,
You have developed an allergic reaction
and penicillin cannot treat allergic reaction.
Apply a mild steroid lotion like desonide
Also take an antihistamine tablet.
This will give you some relief.
treatment with oral steroids
may be required.
Please meet a dermatologist
for exact diagnosis.
Let me know if you have any other doubt.
you can ask a direct question to me on this forum, following the below link.
Wishing you a good health.