Oh you're most welcome!
Another thing --- no steroids, oral or injected for 2 months prior to a dh biopsy. Lay off any topical steroid creams for 2 weeks prior.
Really, stand your ground with them. It would also be great if you can get a friend or family member to go with you in case they take the biopsy from somewhere that you can't see such as the back of your neck. Your friend/family member can watch to make sure they don't take it directly ON a lesion.
Do you have a primary care doc? You can also go to that doc & ask for a full celiac panel PLUS an eTG or TG3. 60% of people with dh test negative on the celiac blood panel but maybe you're one of the 40% who will test positive. It's worth a shot.
Do you have copies of your blood test results? Can you post them? Don't forget to list the reference ranges. Is the TTG the only celiac test they did?
Do you have a copy of your pathology report? Get it if you don't. How many biopsies did they take & from what areas?
Were you eating gluten right up until the biopsy?
I got them on the back side of my knees too. All the literature points out knees & elbows but doesn't mention the "behind the knee" portion of your leg. I eventually got them ON the knees itself but that was one of the last places to present. I also got them on the inside bend of my arm instead of the elbow and just like the knees, it eventually presented on my elbows. Not to be forgotten; the literature also states it can present anywhere on the body.
If you found those links I've posted about how a dh biopsy is done correctly then print them out & take them with you to SHOW them. Any derm should be able to follow the directions or they should turn in their license. As to them saying herpes, well duhhhhhhhhhhhhhhhhhhhh, dh does have a herpes like presentation. That's why they call it dermatitis herpetiformis! Remember, they work for YOU, not the other way around. Insist. Make sure you're still eating gluten. Let us know how it goes. The best of luck to you!