Recurrent Acute Urticaria
Recurrent Acute Urticaria: Mechanisms & Mediators What is Recurrent Acute Urticaria? Recurrent acute urticaria refers to repeated, temporary episodes of hives (itchy, raised welts) where each individual flare resolves completely within a few days or weeks, but episodes keep returning over time. If individual outbreaks last less than 6 weeks at a time, it is classified as acute urticaria rather than chronic urticaria (which persists continuously past 6 weeks). Why It Is Often Non-Allergic While true type-I IgE-mediated allergies (like a severe peanut or bee sting allergy) do cause hives, the majority of recurrent acute episodes—especially those triggered by viruses, NSAIDs, cold air, or stress—do not involve a true allergen at all. Instead, they stem from direct activation of mast cells and basophils (the immune system's primary alarm cells in the skin), which can be setting off their defense response without an allergen binding to an IgE antibody. What the Body Releases Besid...