I think most of the dh sufferers that did try Dapsone & could not tolerate it (side effects) as well as those who did fine on it do not visit the site anymore. I will say that from my experience on the site; the majority who tried it had side effects too badly to stay on it. I have never tried it & don't believe I can b/c I'm allergic to sulfa drugs as is the case with many it seems.
Also, from my experience on here; pretty much 100% had crazy bad, bone deep itch. You can't sleep @ night & if you fall asleep you will be woken in short order from the itching. It's just insane!!!!
I found a couple links for you re: the steroids affecting biopsies. The biopsy is looking for IGA deposited under the skin which is what the rash results from. These links refer to steroid use affecting the IGA in the celiac blood work & state 1 month. The skin is different & would take longer (just as it takes longer to get the antibodies out of the skin) to get out of the skin. But judge for yourself.