Hives are a skin reaction that causes red or white itchy welts. The welts vary in size and appear and fade repeatedly as the reaction runs its course.
Chronic hives are a condition in which the welts last more than six weeks or recur over months or years. Chronic hives usually aren’t life-threatening. But the condition can be very uncomfortable and interfere with sleep and daily activities.
Often, the cause of chronic hives is not clear. In some cases, chronic hives are a sign of an underlying health problem, such as thyroid disease or lupus.
You can try various treatments to relieve your symptoms. For many people, antihistamine and anti-itch medications provide relief from chronic hives.
Read more:
http://acaai.org/allergies/types/skin-allergies/hives-urticaria
https://www.allergyuk.org/skin-allergy/urticaria-and-angiodema
http://www.mayoclinic.org/diseases-conditions/chronic-hives/basics/definition/con-20031634
http://emedicine.medscape.com/article/762917-overview
