Hives Triggered by Heat, Sweat and Exercise
Cholinergic urticaria is a type of physical hives that appears when your core body temperature rises. It is one of the more common forms of inducible urticaria and mostly affects teens and young adults. The welts are small, itchy or stinging, and usually fade within an hour.
What Does Cholinergic Urticaria Look Like?
The hallmark is a crop of tiny wheals, usually 1 to 3 millimeters wide, surrounded by a larger red flare. They often start on the neck, chest and arms and can spread. Many people also feel prickling, burning or warmth before the bumps appear. See our guide to what hives look like for comparison.
Common Triggers
Anything that raises body temperature or triggers sweating can set it off:
- Exercise and sports
- Hot showers, baths and saunas
- Spicy foods and hot drinks
- Fever
- Emotional stress or anxiety
How Cholinergic Urticaria Is Diagnosed
A doctor usually diagnoses it from your history. A supervised exercise or warm-water challenge may be used to reproduce the bumps. It is worth separating it from exercise-induced urticaria, which causes larger wheals, and from exercise-induced anaphylaxis, which is more serious.
Managing Cholinergic Urticaria
Non-sedating antihistamines taken daily, under a doctor’s guidance, are the usual first step. Practical measures help too: warm up gradually, use lukewarm showers, wear loose breathable clothing, and keep a trigger diary. Some people find regular, gradual exercise lowers their reactions over time, but this varies. Stop exercising and cool down if hives or lightheadedness appear.
When to Call 911
Call 911 or go to the nearest emergency room right away if hives come with trouble breathing, wheezing, tightness in the throat, swelling of the tongue or lips, dizziness or fainting. These can be signs of anaphylaxis, a severe allergic reaction that needs immediate treatment.
When to See a Doctor
See a doctor if your symptoms last more than a few days, keep coming back, cover large areas, or interfere with sleep or daily life. Dr. Tiffany Young’s Hives Treatment Center in San Francisco offers online and in-person consultations for patients with cholinergic urticaria.
Frequently Asked Questions About Cholinergic Urticaria
Is cholinergic urticaria dangerous?
Usually not, but it can occasionally cause wheezing, dizziness or swelling. Seek emergency care if you have trouble breathing or feel faint.
Does cholinergic urticaria go away?
Many people improve over several years, though the course varies. Some have flares for a long time.
Can stress cause cholinergic urticaria?
Emotional stress can raise body temperature and heart rate and may trigger or worsen episodes in some people. Read more about stress hives.
Get Relief for Your Hives
Frequent heat-triggered hives respond best to a personalized plan. Visit our hives treatment page to see the latest treatment options for your outbreak.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. If you think you are having a medical emergency, call 911.
