I was diagnosed with Grover's about 30 years ago after moving to Hawaii. Topical steroids have never really worked that well. When it gets really bad I have to take Prednisone. However, my derm recently prescribed the antibiotic Cephalexin. Gone after only a couple days! Holy Crap! And, it's having a hard time coming back. So, I rub a little triamcinolone which takes care of it. Keeping fingers crossed. Might even try sun bathing. That always has aggravated it but maybe not now after the antibiotics.