In the internet research I've done, sweating IS the worst trigger for a flare up of Grover's Disease, which I've had since the 90's. I've started taking much cooler showers, which seems to be helping somewhat. The internet suggested bathing LESS. GD used to be a minor annoyance but these days, it's been really bad and topical steroid creams that used to work are not working any longer. The creams control the itching but not the outbreaks. My dermatologist suggested I try UVA treatment. Don't do it! It made it worse. I now have GD on my legs, which I didn't have before. It was limited to my torso. It's really bad under my breasts now, too and I think my bra is aggrevating it (as it promotes sweating). None of the internet info ties outbreaks to stress--but I'm convinced there is a link. I'm under a huge amount of stress now and the GD has never been this bad before. I don't know what to try and my dermatologist reminds me GD is a "rare disease" and no one is really doing any research or studies on it now. It's ugly and I hate it. I'm shocked I found people discussing it here. I'm happy to hear what anyone has to suggest.