What are the effects of elevation changes?

The daily change in elevation isn't unhealthy in and of itself. However, you may have an acclimation period while your body gets used to such changes. You might aid your body by changing your diet. You have to inhale more air and your lungs are under more pressure while in higher elevation so getting exercise is risky. Don't drink or smoke too much, if at all, the alcohol and nicotine circulates quicker through your blood, causing light-headedness. Try to steer clear of fast food which may elevate your blood pressure and cause the stress that consumes energy and causes headaches. Instead, drink plenty of water, eat foods high in antioxidants and carbs and a multivitamin daily.

Once acclimatized, you may find it's quite nice and relaxing living in the mountains, I certainly have.

The pressure is either greater or less than your use to, so your ears pop to adjust so your not as light headed from pressure change. Ever press really hard on either side of your head? Pressure change, and your head feels different. If pressure decreases, then there is less on your head, so your head feels lighter. I don't know if that can cause rashes though, you might just be sweating and there's something new in the air reacting with it. You might want to see a dr. about the rash, but the ears popping and light headedness should go away after you adjust to your surroundings.