Chronic spontaneous urticaria (CSU) is the medical name for hives that:
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Have no known cause
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Lasts a long time
Chronic = Lasts 6 weeks or longer
Spontaneous = No obvious cause or trigger
Urticaria = red and itchy raised welts or spots on the skin (hives)
What causes CSU?
When your immune system detects a threat, it releases histamine and other inflammatory chemicals.
Histamine can dilate blood vessels, which can cause swelling, itching, and redness of the skin.
What triggers hives?
The most common triggers for hives usually include:
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Allergies
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Bacterial infections, including urinary tract infections and strep throat
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Viral infections, including colds and mono
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Certain medicines, including antibiotics and ibuprofen
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Extremely hot or cold temperatures
Unlike other types of hives, CSU usually has no identifiable trigger and the cause is unknown. But it is often associated with type 2 inflammation.
Type 2 inflammation = an overactive immune response that can contribute to inflammatory diseases.
Treatments for CSU
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Antihistamines are used first
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Biologics (monoclonal antibodies that target the immune system) if symptoms are still not controlled
Help for the CSU
If you have hives that last six weeks or longer or keep coming back, talk to your primary care doctor, dermatologist, or allergist.
This educational resource was created with support from Regeneron and Sanofi.
