urticaria
"I have had cholinergic urticaria for a few years now. I break out into hives when I start exerting myself physically or it's hot. After taking Zyrtec 1/2 an hour before my workout, I didn't experience that irritating itchy feeling all over nor did I get hives. My skin got red but no bumps. I don't care as long as I don't get the irritation which works to create an aversion to exercise. I took a 5 mg dosage. After my workout, I went to sleep at 7 p.m., woke up for an hour and then went to bed at 9 p.m. only to sleep the whole following day. I was unusually fatigued and sleepy. I'm going to try 2.5 mg today to see if that helps."