Can You Pinpoint Chronic Spontaneous Urticaria Triggers?

Medically Reviewed by Neha Pathak, MD on October 08, 2021
4 min read

The intense itching. The sleepless nights. The unpredictability. All the things you’ve tried to get rid of your hives -- or at least to calm the itch a bit. If you’ve been diagnosed with chronic spontaneous urticaria (CSU), also known as chronic hives, you know how frustrating and life-altering it can be. What more can you do, especially when your doctor doesn’t know what’s causing it? (And you’re not alone there; a cause isn’t found in 80% to 90% of people with CSU.)

Though they’re not the underlying cause of CSU, some things have the potential to aggravate your condition, says Jacquelyn Sink, MD, a dermatologist at Northwestern Medicine Regional Medical Group in Chicago.

This is actually good news because with some careful tracking, you just may be able to figure out exactly what your personal triggers are. And if you can ID your triggers, you can take steps to avoid them.

What triggers CSU is different for everyone, says Ohara Aivaz, MD, a dermatologist and internist at Cedars-Sinai Medical Group in Los Angeles. But there are plenty of things that are known to cause flare-ups or make CSU worse in many people. Common triggers include:

  • Nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin and ibuprofen
  • Antibiotics, particularly penicillin and sulfa
  • Narcotics (pain medications)
  • Lack of sleep
  • Stress
  • Alcohol
  • Rich meals
  • Spicy or fermented foods
  • Dramatic changes in your diet
  • Environmental factors such as sunlight, cold, and heat (like hot showers or extreme humidity)
  • Tight clothing, straps, or areas of friction such as under your arms and on your inner thighs
  • Menstrual cycle
  • Not taking your antihistamine regularly
  • Illness or infection

When you have hives that just won’t go away, it’s important to see a doctor. You’ll need tests to make sure there isn’t a medical cause like an infection, a medication, or a disease such as rheumatoid arthritis, diabetes, or a thyroid condition. Aivaz says these blood tests should be included to help your doctor rule out those problems:

  • A complete blood count (CBC) with differential. These numbers are often normal in people with CSU. Rarely, very high counts of a type of white blood cell called eosinophils can be a sign that an allergic disorder or parasitic infection is causing the CSU, Aivaz says.
  • C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR). These are often normal too. Very high values can show that your CSU is severe and won’t respond to antihistamines. If these levels are elevated, your doctor should look for an underlying systemic disease such as an autoimmune condition, infection, or cancer, Aivaz says.
  • Thyroid-stimulating hormone (TSH) and thyroid antibodies. These tests check for thyroid disease, which is more common in people with CSU.

Your doctor may also do a skin biopsy to rule out other skin problems, Sink says.

A diagnosis of CSU means there’s no clear trigger or cause behind every episode of chronic hives. If your hives are triggered most or all of the time by something specific, CSU isn’t the right diagnosis, and your doctor will need to look at what else could be going on, Sink says.

For instance, if you primarily get hives because of physical things like heat, cold, exercise, water, or sunlight, the best diagnosis is physical (or inducible) urticaria. Some people have both CSU and inducible urticaria. Many people with CSU have some flares that are triggered by physical things; they’re just not the main trigger of their symptoms, like they are with inducible urticaria.

When your symptoms flare, it’s a good idea to keep a diary. You may notice a pattern, which can help you pinpoint and avoid anything that could be a trigger for making your hives worse or causing a flare-up. Avoiding your triggers may lower the frequency and severity of your symptoms, according to Sink.

Keep track of things like:

  • Where the hives appear
  • Foods you’ve eaten
  • Exposure to cold, heat, or sunlight
  • What you were doing when the hives began
  • All the medications (both over-the-counter and prescription), supplements, and herbs you’ve taken
  • How much sleep you got the night before
  • Things you may have touched or used, such as plants, animals, or chemicals

If you don’t want to track all these, think about starting a food diary. Aivaz says this can help you spot food allergens that may be triggering your flares.

Think about keeping a mood journal too, especially if you think stress might be a trigger. This can help you identify what causes your stress so you can work on minimizing it. Less stress may help you manage your CSU, Sink says.

When you feel discouraged and frustrated, remember that it’s rare for CSU to be permanent. Half of cases go into remission within a year, and most resolve within 5 years. CSU isn’t an allergic reaction, so it’s also rare for it to cause severe problems. And, maybe most important, the symptoms can be controlled for most people. Identifying your personal triggers is an important tool that may help you manage your disease.