I have no personal experience to share.
I do have a suggestion of a professional resource that may be helpful - here's a link to the IBD Working Group website. You will have to register (free) to access the content.
www.ibdwg.org/index.cfmThe website has a case-study article about
a patient with UC and Ulcerative PG. Here's a link directly to the article by Dr. Aaron Brzezinski, of the Cleveland Clinic.
thecdwg.org/decisionMaps/brzezinski/index.cfmIf the link doesn't work you can access it from the IBDWG main page by going to Curbside Consults and
opening the Archive link to past Decision Maps.
The article doesn't specifically address your question but does discuss treatment of a patient with recurrent PG and differential diagnoses.
Perhaps the references for the article or Dr. Brzezinski may be helpful resources for you.
You don't say that your patient has IBD so please forgive me if this info is not applicable.