Re: Can't handle this mystery allergy
Hives happen sometimes. They might be caused by a food or medicine, or by something you touched. Since it started on your legs, a food is not the most likely explanation.
Under "something you touched" it could be: Soap, laundry soap, moisturizer, sunscreen, bug repellent, industrial cleansers, perfume, or anything you're exposed to at work. Remember, it could be something you've used for years, especially if the manufacturer tweaked the formula a bit, which they do all the time.
Or it could be a medicine or food, including one you've had safely before.
For now, the best way to reduce the itching is to physically stay cool. Getting hot and sweaty will make it worse, cool rooms, light clothing, and cool showers will help.