I'm not aware of any foods being related to HS. I was a vegan and still got it, on a raw diet and still got it, etc. I've never read, been told by dr or another sufferer that certain foods can cause flares or anything. You could ask a dermatologist though. It could've been because your body was already on the defense because you were sick. Were you on antibiotics or anything?
I forgot, I once read somewhere someone believed theirs was associates with potatoes. They cut them out and hadn't had a flare since. I tried no potatoes for a couple months after this, no luck. The cause of HS is unknown. Some researchers have tried to link it to a few conditions (thyroid, RA, Chron's Etc), But like many sufferers I have none of these so this doesn't help. There's some good quotes about all this in another thread, I think it's called something like Thyroid conditions and HS. Hope this helps!