What Is Chronic Spontaneous Urticaria? Experts Break Down What You Need to Know

If you’ve ever had an allergic reaction that includes hives—a rash with itchy, raised bumps or welts—then you know how uncomfortable they are. In addition to the intense, sometimes uncontrollable itching, hives can also burn, sting and swell.

The good news is that hives are typically short-lived and go away on their own once you take allergy medication—that is, unless you have chronic spontaneous urticaria (CSU). In that case, your hives may last for long periods of time.

CSU, also known as chronic hives, affects 1.4% of the population, and women are twice as likely to be diagnosed with the condition than men, according to the American College of Allergy, Asthma & Immunology (ACAAI). Not only that, but CSU is most common in adults aged 30 to 50 and most prevalent in women in their 40s, a 2019 study in the Journal of the American Academy of Dermatology found.

But if you’ve never heard of it, you’re not alone. Here’s what to know about CSU including the symptoms and treatment options. 

What Is Chronic Spontaneous Urticaria?

Chronic Spontaneous Urticaria, or CSU, is a condition where hives and sometimes deeper swelling—called angioedema—appear on the skin without any clear external trigger, says Dr. Hannah Kopelman, a dermatologist at teledermatology platform DermOnDemand.

“The keyword here is ‘chronic,’” she explains. “These outbreaks last for six weeks or more and often seem to occur randomly.” 

The random nature of CSU is another hallmark of the condition.

“The term ‘spontaneous’ indicates that it occurs without an identifiable external trigger such as food, medication or physical stimuli—like pressure, cold or heat,” says Dr. Helen A Brough, a professor of pediatric allergy at King’s College London.

Unlike allergic reactions, which usually have a clear cause, CSU often persists despite eliminating potential allergens, which Kopelman says makes it more challenging for patients to understand.

What Are the Symptoms of Chronic Spontaneous Urticaria?

Unsurprisingly, the most common symptom of CSU is itchy, raised hives: red or skin-colored welts that vary in size, says Dr. Shamsa Kanwal, a consultant dermatologist. The other hallmark symptoms include swelling—especially around the lips, eyelids or extremities—and a burning or stinging sensation in affected areas.

You may also get hives that change location and resolve within 24 hours, Kopelman says, as well as skin lesions that reappear daily or almost daily for weeks. 

“Additional symptoms can include fatigue, sleep disturbance or anxiety—mostly related to the chronic discomfort,” she says. “If you notice recurring hives without a clear cause, or if they’re lasting more than six weeks, that’s a strong sign to get evaluated for CSU.”

According to Brough, other key signs that you’re dealing with CSU include:

• Hives occurring most days of the week for more than 6 weeks
• Hives not responding to common antihistamines
• Lack of identifiable allergenic triggers
• Swelling without hives
• Interference with daily life, sleep or mood

To ensure that you’re prepared when you see a doctor, Kanwal recommends keeping a record of your symptoms: when they started, how long they last and any patterns you notice. 

According to Brough, you should also keep track of: 

• Whether your hives move around or resolve within 24 hours
• Any potential triggers or patterns (even if none are obvious)
• Medications, supplements and/or lifestyle factors
• Family history of autoimmune or allergic conditions
• Response to over-the-counter antihistamines or other therapies

“A dermatologist, allergist or general practitioner can start the evaluation, but dermatologists are often the first step for skin-related symptoms,” Kanwal says.

What Causes Chronic Spontaneous Urticaria?

The exact cause of CSU isn’t fully understood, which Kopelman says makes it difficult to manage.

“Most evidence points to autoimmune activity—meaning the body’s immune system is mistakenly triggering mast cells in the skin to release histamine, which causes hives and swelling,” she says.

According to Brough, up to 40% of CSU cases involve immunoglobulin E (IgE) autoantibodies, or IgE itself. Additionally, CSU is associated with a number of other autoimmune conditions, including type I diabetes, rheumatoid arthritis, celiac disease, systemic lupus erythematosus (SLE), polymyositis, dermatomyositis and Sjögren’s syndrome, per a 2019 study in the journal Frontiers in Immunology. 

There are also some exacerbating factors that can act as potential triggers for CSU but aren’t root causes in the traditional sense, Kopelman explains.

For example, some cases of CSU may follow a viral or bacterial infection, Brough says. In other instances, emotional stress can trigger or exacerbate CSU, she notes. Hormonal changes—especially perimenopause and menopause—are also believed to play a role.

“Shifts in estrogen and progesterone may influence immune reactivity and mast cell stability,” Brough explains. However, despite these theories, the majority of CSU cases remain idiopathic—meaning no known cause can be identified, she clarifies. 

How Does Chronic Spontaneous Urticaria Impact Midlife Women?

Midlife women are more likely to experience CSU than any other group. “In my practice, I’ve seen CSU disproportionately affect women in their 40s and 50s—especially during perimenopause and menopause,” Kopelman says. “Hormonal fluctuations, particularly changes in estrogen, may destabilize mast cells and make the skin more reactive.”

Additionally, there’s also a higher prevalence of autoimmune conditions in women during this life stage, which might be part of the link, Kopelman says. This includes conditions like Hashimoto’s thyroiditis, lupus and rheumatoid arthritis. 

“On top of that, stress and sleep disruption—both common in midlife—can make flare-ups worse,” she says.

Stress from multitasking roles, like caregiving and attempting to have some kind of work-life balance, may exacerbate symptoms or lower tolerance thresholds, Brough adds. Sleep can be a vicious cycle: a lack of sleep can trigger symptoms, but having itchy, uncomfortable hives also makes it much harder to get restful sleep. 

The effects of CSU go beyond the physical symptoms, Brough points out, including causing a decreased quality of life. CSU may also take an emotional toll, she says, and, as a result, are often mistaken for anxiety or stress-related hives—and in some cases, dismissed.

Finally, CSU may be misdiagnosed or underdiagnosed in midlife women because of gender bias or attributing symptoms to “hormonal issues,” she notes.

How Do You Treat Chronic Spontaneous Urticaria?

Treatment for CSU usually starts with high-dose, non-sedating antihistamines—often more than the typical over-the-counter dose, Kopelman says.

If that’s not enough, doctors may add leukotriene receptor antagonists, short courses of corticosteroids, or try an injectable biologic,” she explains. “In more stubborn cases, immunosuppressants like cyclosporine may be used under specialist supervision,” she adds.

While being treated for CSU, it’s also important to avoid known aggravators, like tight clothing, NSAIDs, alcohol and heat, and to manage your stress, Brough says.

Is There a Cure for CSU?

While there is no guaranteed cure, the good news is that CSU can go into remission, Kanwal explains.

According to Brough, many cases of CSU resolve spontaneously—around 50% within one to five years.

“Some people experience symptoms for a few months; others for a few years,” Kopelman says. “The key is finding a treatment plan that controls your symptoms and reduces flare-ups while minimizing medication side effects. With the right approach, most people can live comfortably with CSU.” So, if you’re experiencing any CSU-related symptoms its important to talk to your healthcare provider to discuss the right course of treatment.

All content independently developed by SHE Media with the support of Novartis Pharmaceuticals Corporation.