For me it's what are called nightshade vegetables ... Potatoes, peppers, eggplant, and I eat less tomato. If I avoid especially potatoes I have only had 2 flare-ups in the last couple years

Only by trial and error I have found that too much fruit causes flare ups for me. I limit myself to maximum 2 servings a day at the moment - I could quite easily graze on fruit all day.

I am on the keto diet, it eliminates my HS. We are all different so may not work on you, but might be worth a try. Hard for some to give up sugars and carbs (potatoes, pasta, rices and breads) You will know in a week if it works, and 2 weeks you will be really impressed it it works for you. There are others that it works on, not just me!