Few conditions are as disruptive as chronic hives. The itching is relentless, the visible welts are unpredictable, and the most common reaction from outside — "what are you allergic to?" — is almost always the wrong question. Most chronic urticaria is not allergic at all.
Acute vs chronic urticaria
The distinction matters because the cause and the treatment are different:
- Acute urticaria lasts less than 6 weeks. Common triggers include viral infections, drug reactions, and occasionally food allergies. Most resolve spontaneously.
- Chronic urticaria persists for 6 weeks or more, with hives appearing on most days. In the majority of these patients, no specific trigger is ever identified.
This is where the confusion starts. Patients with chronic urticaria are often told to eliminate foods, switch detergents, throw out cosmetics, change their diet entirely. These efforts rarely change outcomes, because the underlying mechanism is not allergic.
What is actually happening
Chronic spontaneous urticaria (CSU) is now understood as an immune-mediated condition. In roughly 40% of patients, there is detectable autoreactive IgG against the IgE receptor (FcεRI) on mast cells, or against IgE itself. In another subset, the mechanism is more subtle but still consistent with mast-cell hyperactivation. Whatever the upstream cause, the final common pathway is histamine and other mediators released from mast cells — producing the hives, swelling, and itch.
First line — second-generation antihistamines
Treatment begins with a non-sedating second-generation H1 antihistamine: cetirizine, loratadine, fexofenadine, or bilastine. The licensed dose (usually once daily) controls a portion of patients.
For those who don't respond, current guidelines support up-titration to four times the licensed dose. This is one of the most under-applied steps in primary care. Patients are often told "the antihistamine isn't working" when the issue is that the dose was never escalated. At 4x dosing, a substantial proportion of patients who failed at standard dose achieve good control.
When antihistamines aren't enough — omalizumab
For patients whose hives persist despite four-fold antihistamine dosing, the next step is omalizumab, an anti-IgE biologic given as a subcutaneous injection every 4 weeks. The typical CSU dose is 300mg, though 150mg works for some patients.
Most responders see meaningful improvement within 6 to 12 weeks. The benefit is generally well-tolerated, and the safety profile after years of use in both asthma and urticaria is reassuring. Other systemic options exist (cyclosporine, dapsone) but are reserved for refractory cases or used in specific contexts.
What to avoid
Two things commonly waste time and patient money:
- Extensive food allergy panels looking for an allergic cause. In chronic urticaria these are almost always negative or misleading, and pursuing them delays effective treatment.
- Restrictive elimination diets. They rarely change the underlying disease and often create new problems.
When to refer
- Hives persisting for more than 6 weeks
- Symptoms not controlled on max-dose second-generation antihistamines
- Co-existing angioedema or systemic symptoms
- Patient distress, sleep disturbance, or impact on daily life that warrants escalation
Our Allergy Rapid Access Clinic sees most referred patients within the same week. Chronic urticaria is one of the most rewarding conditions to treat once the right ladder is followed — the vast majority of patients are fully controlled.