Yes it is possible that a topical skin cream can cause a flare. There are many threads warning about
different topicals that can aggravate Crohn's or UC. Here is one example:
stkitt said...
Do not use Clindamycin lotion if you have Crohn disease, antibiotic-associated colitis, or ulcerative colitis. Call your physician and explain the info included with the medication as he will most likely tell you not to use this lotion but perhaps will have another Rx for you to use.
https://www.healingwell.com/community/default.aspx?f=17&m=2164454