Cholinergic Hives help!?

Okay I'm a freshmen in high school, and since september i started getting these hives, it started out little but now it's driving me insane! These hives i get are when i play tennis and after hot showers so im guessing its cholinergic hives after doing research. I don't know why the hell after 12 years im suddenly allergic to body heat, but yeah. My piano teacher(whos a nurse) says its because of hormone change, but if i get medicine wouldn't it involve regular shots when the hives come or will it be like pills?

i have this condition also and i am in the army before a workout i usually take claritin or zyrtec and it usually helps

Cholinergic urticaria can be treated by limiting strenuous exercise. It responds well to a medication called hydroxyzine, which is an antihistamine. However, the main side effect of sleepiness is often not tolerated well. Showering with hot water may cause a release of histamine throughout the body depleting histamine stores and causing a 24-hour refractory period.

i no how u feel about it driving u insane ive giaint uticaria n had it for 3 years the best thing to do is sleep naked n keep cool if it itches put camomile lotion on it but try not to scratch it makes it worse if its the hot showers makin it worse before u get out of the shower put it on cool for one min some medication works for some where it dont for others i was put on steroids it wernt nice. its all well asking yr piano teacher but she isnt yr doctor he will be able to tell u more because he nos more about u