This is defined as hives lasting longer than 6 weeks.
Patients like this come in miserable and worried with this problem, often having seen multiple specialists.
Common reasons for lack of effectiveness of antihistamines are 1) the particular antihistamine used is not strong enough 2) the antihistamine is not used in a high enough dose 3) the antihistamines are not continued for a long enough period.
The most well tolerated initial treatment are the non-sedating antihistamines like fexofenadine, loratidine, and cetirizine.
In about half of patients with chronic idiopathic hives, the explanation is that body's immune system is, in a sense, overactive. The immune system is attacking the normal tissues of the body and causing hives as a result.
We know certain urticaria sufferers have other signs of autoimmune problems.
Because of those 5% of cases with a cause, it is worthwhile to see a physician to determine if any underlying disease is present (e.g.Some have autoimmune thyroid disease, vitiligo, swollen joints, or certain abnormalities in the blood (especially the ANA test).A new treatment has recently emerged for autoimmune urticaria.So, in many patients with chronic hives, there is really no exposure (drug, food, insect, chemical) to blame for the urticaria.The patient must understand and accept this for their ideal management.