Which preposition to use with excoriation

of Occurrences 4%

At other times, though fortunately very rarely, excoriation of the navel and the parts around takes place, which quickly spreads, and assumes an angry and threatening character.

in Occurrences 1%

Strangely he smiled as he observed the nicks and deep excoriations in stock and barrel of the formidable weapon.

Which preposition to use with  excoriation