Urticaria may be acute or chronic. As opposed to acute urticaria, chronic urticaria is defined by recurrent episodes occurring at least twice a week for 6 weeks (Grattan, Sabroe, & Greaves ...

Doctors refer to these hives as "acute urticaria." Hives that recur several times a week for longer than 6 weeks are called "chronic urticaria." In about half of patients with "chronic spontaneous ...

Acute urticaria (hives) is a common skin condition that affects up to 20% of people at some point in their lives. It can ...