MyUC here. First here is the article,
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2418916/pdf/postmedj00106-0024.pdf
It basically says that eosinophilia is and can be a manifestation of ulcerative colitis. It's rare but well documented. I was on prednisone for my colitis on and off for about 10 years. Eventually prednisone didn't do anything for my elevated wbc/eosinophil count. The steroids just caused my wbc to continue to elevate. Hence the Imuran. That put everything back into check. I also have occasional asthma and some various allergies. I went through patch testing but it didn't really come up with anything substantial. My colonscopies, prior to Imuran, showed abundant eosinophils in my colonic mucosa. Before the Imuran my colon was heavily affected by my pancolitis. Once the Imuran healed my colon the eosinophils dropped. My last colonscopy showed a 98% normal colon. My bloodwork has showed a normal wbc for the last 2+years and my eosinophil count is now just above normal. Not even twice normal, it's within a few hundred of normal. Not only did I see allegist/immunologists but I saw and am seeing an allergist/immunologist that is the clinical director of eosinophilic disorders at one of the best medical teaching institutions in the world.
Any other question? I am glad to help.
MyUC