Why Do Some People Develop Long-Term Hives, or Chronic Spontaneous Urticaria?

Chronic spontaneous urticaria (CSU) is a skin condition that causes itchy, raised outbreaks of hives on the skin that last at least six weeks. Unlike typical hives, CSU appears without a clear trigger, such as food, medications, or contact with an irritant.

CSU causes itchy, raised skin patches or lesions called papules or hives. Usually, hives (or hives) are a sign of an allergic reaction and last from a few hours to a few days. However, with CSU, the hives are present somewhere on the body for at least six weeks and the cause may be uncertain.

Rather than being caused by an allergy or environmental trigger, experts believe that CSU is usually autoimmune in origin, meaning it occurs when your immune system becomes overactive.

In more than half of CSU cases, the immune system randomly activates infection-fighting cells called mast cells. These mast cells are found under the skin, and when activated, they release histamine and other chemicals. This can lead to leaky blood vessels and the formation of hives.

Experts aren’t sure why people with CSU have overactive immune systems, although genetic changes can make a person more vulnerable to the disease.

Other possible causes of CSU may include:

• Infections: Some research has linked CSU to hepatitis A or C, digestive system infections, and bacterial infections.
• Associated autoimmune diseases: CSU can sometimes be an early manifestation of an autoimmune disease, such as systemic lupus erythematosus (SLE), celiac disease, type 1 diabetes, and autoimmune thyroid disease.
• External triggers: Although it is less common, CSU can sometimes be caused by external or environmental triggers. This may include stress, hormonal changes, taking nonsteroidal anti-inflammatory drugs (NSAIDs), pressure, water, cold, heat, exercise, vibration, and sunlight.

People who develop ASC are also more likely to have allergic rhinitis (hay fever), asthma, or atopic dermatitis (eczema), although these do not appear to cause the condition.

CSU causes smooth, itchy bumps or papules on your skin. These papules often appear red or pink on fair or medium skin. On darker skin tones, they may have lighter or darker shades of brown.

Hives can appear anywhere on your body and vary greatly in size and shape. Individual papules usually disappear on their own within 24 hours, but new ones usually appear in different areas.

If you suffer from CSU, you may experience:

• Mild to intense itching
• A tingling or burning sensation in the affected areas
• Welts that turn white or pale when you press on them
• Impaired quality of life, such as sleep disturbances, sexual dysfunction, or mental health problems

About four in 10 people with CSU also have angioedema, which is a deep swelling under the skin. Angioedema often affects the lips or the area around the eyes, or less commonly, the genitals, hands, or feet. This may cause tingling, numbness, or pain.

It is often difficult to determine the cause of CSU: it may be a person’s immune system, an infection, or another unknown factor. For this reason, you cannot always prevent it.

However, people who develop the disease may be able to reduce symptom flare-ups by avoiding known triggers. Keeping a symptom diary can help you identify whether specific factors, such as heat or stress, are making your hives worse.

Common strategies include:

• Avoiding certain medications like aspirin and ibuprofen
• Minimize pressure from belts or tight clothing that causes friction
• Manage stress through mindfulness, yoga, or journaling

CSU usually goes away on its own. For about 50% of people, the problem disappears within six months. In others it lasts longer, but rarely 10 years or more. Cases tend to persist longer if a person has autoimmune thyroid problems or also has angioedema or intense swelling.

However, UCC can be treated: the main goal is to help patients control their symptoms and improve their quality of life. Health care providers start your treatment plan with standard medications and increase the dose if necessary.

Common treatments include:

• Second generation antihistamines: These are usually recommended first, and people with CSU will usually be advised to take them daily. Second-generation antihistamines work by blocking histamine receptors in your skin to reduce itching and swelling. Examples include cetirizine, loratadine, and fexofenadine.
• High dose antihistamines: If your symptoms do not improve with the standard dose, your doctor may increase it up to four times. About 40% of people with CSU will see a significant reduction in their symptoms with these medications.
• Omalizumab: If antihistamine medications don’t work, omalizumab is a good alternative. This injectable medication targets your immune system and prevents mast cell activation. Research suggests that this method helps up to 70% of CSU patients.
• Cyclosporine: If nothing else helps, doctors may consider cyclosporine. This medication dampens an overactive immune system, but can also cause unpleasant side effects, including high blood pressure or problems with kidney function.

Usually, hives go away on their own. But if they persist and you think you might be suffering from CSU, it’s best to see a doctor to rule out other conditions or get treatment.

A dermatologist, immunologist, or allergist usually manages CSU. They may perform screening tests like a complete blood count or C-reactive protein (CRP) test to rule out underlying disorders.

If at any time your hives become widespread or you develop other serious symptoms, such as swelling of the throat or tongue or difficulty breathing, seek emergency medical attention. These may be signs of a life-threatening allergic reaction called anaphylaxis.