Thanks for the query.
you might have developed a corn
The treatment for this will be a combination of antibiotics and salycilic acid.
Antibiotics will take care of infection and salicylic will reduce the size of lump.
Please meet a dermatologist
and discuss regarding this.
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.