Every day with Chronic Spontaneous Urticaria raises a new question

What is chronic spontaneous urticaria?

Chronic spontaneous urticaria (CSU) is a condition in which itchy raised welts, swelling beneath the skin, or both occur repeatedly for more than six weeks without a consistent external trigger. Individual hives usually fade within 24 hours, although new ones may continue to appear.

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CSU is not contagious and is usually not caused by a food allergy. It can significantly disrupt sleep, concentration, work and emotional wellbeing. mama health's guide to understanding chronic urticaria covers the condition in full.

What causes chronic spontaneous urticaria?

In many cases, CSU is driven by autoimmune activation of mast cells, which release histamine and other inflammatory mediators in the skin. The exact initiating cause often cannot be identified, which mama health's guide to causes and spontaneous outbreaks covers in more detail. Whether CSU counts as an autoimmune condition, and how thyroid disease fits in, is covered in is CSU autoimmune.

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Heat, pressure, stress, infection, alcohol and certain medicines may worsen symptoms without being the underlying cause. Nonsteroidal anti-inflammatory drugs can aggravate hives in some people. mama health's guides to tracking food, stress and heat triggers, stress and itching and cold and heat-induced urticaria cover the aggravators people ask about most.

Is food causing it?

Food is the first thing most people suspect, and it is usually not the cause. mama health's guide to CSU versus food allergy explains how the two differ and why the distinction matters. For the diets people try anyway, see a low-histamine diet and what the evidence says about diet and CSU. Restricting food without a confirmed trigger can do more harm than good, so any change is worth discussing with the clinician managing the condition.

Treatment options

Second-generation, non-sedating H1 antihistamines are first-line treatment and may be adjusted under medical supervision. Trigger avoidance is recommended only when a reproducible aggravating factor has been identified. mama health's guide to treatment options when symptoms aren't controlled sets out the steps.

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For symptoms that remain uncontrolled, biologic therapy such as omalizumab or other specialist treatments may be considered, covered in what happens when antihistamines aren't enough and starting a biologic. Short courses of oral corticosteroids are sometimes used for severe flares but are not suitable as routine long-term therapy. Reducing antihistamines once symptoms settle is its own decision, covered in reducing antihistamines. Questions between appointments can be put through mama health, which is free urticaria support grounded in medical science and the experience of others.

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Living with chronic spontaneous urticaria

Photographs and a symptom diary help document episodes that disappear before an appointment. Useful details include hive frequency, swelling, medication use, infections, menstrual patterns, pressure or heat exposure, and effects on sleep and daily function. All of it can be kept in one place in the mama health app, a free urticaria app built with in-house doctors.

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Loose clothing, cool compresses, fragrance-free skin products and avoiding known aggravators may provide additional comfort. Painkillers and other medicines are worth reviewing with a clinician rather than stopping necessary treatment independently.

When to seek emergency care

Call emergency services immediately if swelling affects the tongue or throat, breathing becomes difficult, wheezing develops, the voice changes, faintness occurs, or symptoms suggest anaphylaxis. Isolated lip or eyelid swelling without breathing symptoms still requires prompt medical advice if severe or progressive.

How long does CSU last?

CSU often resolves on its own over time, although the duration is unpredictable and symptoms may recur. Most people achieve good control with stepwise treatment even when the underlying cause remains unknown. mama health's guide to how long CSU lasts covers remission and relapse.

Who is at risk of developing chronic spontaneous urticaria?

CSU is more common in women and may occur alongside autoimmune thyroid conditions or other autoimmune conditions. Infections, stress, heat, pressure, alcohol and NSAIDs can aggravate symptoms in some people.

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Major complications are uncommon. Angioedema can be frightening, and sleep and mental health may be substantially affected. Restricting food without a confirmed trigger can also cause unnecessary harm.

What are the symptoms of chronic spontaneous urticaria?

Symptoms include intensely itchy raised wheals that vary in size and shape, appear anywhere on the body, and usually disappear from one spot within 24 hours. Episodes recur on most days or intermittently for more than six weeks.

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Angioedema causes deeper swelling, commonly around the eyelids, lips, hands, feet or genitals, and may feel painful or tight rather than itchy. mama health's guide to CSU with angioedema covers what the swelling means and when to get help. Hives that come from a clear allergic reaction behave differently, covered in allergic urticaria.

How is chronic spontaneous urticaria diagnosed?

Diagnosis is clinical, based primarily on the history and appearance of typical hives or angioedema lasting more than six weeks. A clinician confirms that individual lesions behave like urticaria, asks how long they last, reviews photographs, and checks for angioedema, physical triggers, medications, infections, systemic symptoms and signs suggesting urticarial vasculitis or another disorder.

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Testing is deliberately limited in typical CSU. Extensive allergy testing is usually unnecessary unless the history points to a specific trigger. A complete blood count and markers of inflammation may be considered, with thyroid testing or other targeted studies based on the history. Skin biopsy is reserved for painful, bruising or long-lasting lesions, and allergy tests are used only when a reproducible immediate exposure is suspected. Results and letters can be read back in plain language in the mama health app, a free CSU support app.