Chronic idiopathic urticaria/chronic spontaneous urticaria
Acute urticaria (hives) is often caused by viruses or allergy. Chronic urticaria (hives) lasts longer than 6 weeks and is thought to be autoimmune. Urticaria is itchy, comes and goes, and can move around. The eruptions are spontaneous or inducible by exercise (exercise-induced anaphylaxis and cholinergic urticaria), water (aquagenic urticaria), coldness (cold urticaria), or sunlight (solar urticaria). One-third to two-thirds of cases are associated with angioedema (swelling beneath the skin). If a patient is on an ACEI drug, this must be stopped. Urticaria usually resolves in 24 hours and angioedema in 72 hours. Severity is measured by the weekly urticaria activity score (UAS7). If individual lesions last over 24 hours, a skin biopsy may be required.
The treatment algorithm starts with a second generation antihistamine like cetirizine (10-40mg/day), desloratadine (5-20mg/day), fexofenadine (120-480mg/day), or loratadine (10-40mg/day). These drugs can be increased up to four times the standard dose. Montelukast can be added and exacerbations may be treated with an oral steroid.
Omalizumab and cyclosporine are third-line therapies initiated at the specialist level.
Resources:
CIU Tracker App on App store and Google play
Dr. John's Blog 