Living with chronic hives can be unpredictable and frustrating. Flare-ups may seem to come out of nowhere, and many people spend months — or even years — trying to understand what’s triggering their symptoms. For some, chronic hives happen alongside other health conditions, including autoimmune diseases like type 1 diabetes. While not everyone with chronic hives has type 1 diabetes (and vice versa), understanding how they may overlap can help you better manage your health.

Here are eight important things to know about the link between type 1 diabetes and chronic hives, including why they may happen together, how they’re treated, and what to discuss with your healthcare provider.

1. Both Conditions Have an Immune System Connection

Type 1 diabetes and chronic spontaneous urticaria have something in common — they both happen when the immune system doesn’t work the way it should. In type 1 diabetes, the immune system makes antibodies that mistakenly attack insulin-producing cells in the pancreas.

In chronic hives, the immune system triggers mast cells (a type of white blood cell) to release histamine. This process often involves immunoglobulin E (IgE) antibodies, which cause the release of histamine, the chemical responsible for those itchy welts.

Having one condition doesn’t automatically cause the other. They can happen together because of shared immune system traits, but many people have type 1 diabetes without ever developing chronic hives, and vice versa.

2. You Can Have Both Conditions

While there’s some evidence of a link between type 1 diabetes and chronic hives, the research is pretty limited. One review of past studies found that between 0.2 percent and 5.5 percent of people with chronic hives also have insulin-dependent diabetes (the former term for type 1 diabetes).

There’s more research on acute hives and type 1 diabetes. Research suggests people with type 1 diabetes have a higher risk of developing hives. One large study found that hives happened in 26.6 out of every 1,000 people with type 1 diabetes each year, compared to 6.85 out of every 1,000 people without it. Children under 18 with type 1 diabetes had about 3.6 times the risk compared to those without diabetes.

3. Fluctuating Blood Sugar Levels Don’t Cause Chronic Hives

One common question is whether high or low blood glucose directly triggers hives. Some researchers have wondered if fluctuations in blood sugar might prompt mast cells to release histamine. However, there’s no solid proof that blood glucose levels directly cause chronic hives.

This is important because if you’re experiencing unexplained hives, it doesn’t necessarily mean that your diabetes management is failing. The connection between these conditions seems to stem from shared immune system characteristics rather than blood sugar control itself.

4. They Have Overlapping Triggers

While blood sugar itself isn’t a proven trigger of hives, both conditions have shared triggers that can worsen your symptoms. Illness, stress, or inflammation in the body can make a hive flare-up worse and make it more difficult to manage your blood glucose. This means these factors can impact both chronic hives and a fluctuation in your blood sugar. If you have both conditions, it may seem like one is impacting the other. But in reality, there are factors that can make both conditions worse.

You may notice that when you’re fighting off a cold or going through a stressful period, your hives act up and your blood sugar becomes less predictable. Recognizing this pattern can help you and your healthcare team plan ahead during tough times.

5. People Who Have an Autoimmune Condition Are More Likely To Develop Another

People with one autoimmune disorder — a condition where the body’s immune system mistakenly attacks itself — have a higher chance of developing another. The most common autoimmune conditions people develop in addition to chronic hives include:

• Type 1 diabetes
• Celiac disease
• Thyroid disease

Of these, thyroid disease has the most significant link, with some studies showing rates as high as 50 percent in people with chronic hives. If you have both type 1 diabetes and chronic hives, ask your healthcare provider about testing for thyroid antibodies, especially if you haven’t been checked recently.

6. Hives May Look Similar to Other Diabetes Skin Issues

Several diabetes-related skin conditions resemble hives. Here’s how to tell them apart.

Device-Related Reactions

Reactions to insulin pumps, continuous glucose monitors (CGMs), or other diabetes devices are common but distinct from chronic hives. Caused by adhesives or friction, these reactions appear as discolored or dark patches strictly where the device touches your skin. Unlike hives, which move around the body unpredictably, device reactions stay in one spot.

Insulin Allergies

While rare, true insulin allergies cause welts that can spread across the body, rather than staying at the injection site. If you notice systemic hives shortly after injecting, contact your healthcare provider immediately.

Lipohypertrophy

These are firm lumps under the skin caused by injecting in the same spot too often. Unlike hives, they are solid, don’t itch, and don’t disappear and reappear. Because they can affect insulin absorption, rotating your injection sites is crucial.

Diabetic Dermopathy

Also called “shin spots,” these appear as scaly, discolored patches (light brown, red, or darker spots, depending on your skin tone). Unlike hives, they don’t itch, swell, or come and go quickly. They fade slowly over months or years. They’re harmless but indicate changes in small blood vessels.

If you’re not sure whether your skin rashes are caused by your device, your injection site, or something else, a dermatologist or allergy specialist can help sort it out.

7. Some Chronic Hives Treatments Can Interfere With Type 1 Diabetes Treatment

When chronic hives don’t improve with antihistamines alone, some people may need other treatment options. This is where working with your diabetes care team becomes essential.

Steroid medications like prednisone are sometimes used for severe hive flares. These drugs can significantly raise blood glucose levels, often requiring you to adjust your insulin temporarily. If your dermatologist or allergy specialist suggests steroids, consult your endocrinologist immediately to create an insulin adjustment plan. You may need to increase your insulin doses while taking steroids.

The good news is that the main treatment for chronic hives — nondrowsy antihistamines — is considered safe for people with type 1 diabetes. If antihistamines aren’t enough, omalizumab (Xolair), an anti-IgE medication given by injection, is sometimes used. Case reports, including one describing a 13-year-old with both conditions, suggest omalizumab can be used safely in people with type 1 diabetes without making blood sugar control worse. However, you should always consult your healthcare providers about new treatments for either condition.

8. Logging Your Symptoms Can Help

Given the complex link between type 1 diabetes and chronic hives, keeping a symptom log can give your healthcare provider valuable information.

Write down when hive flares happen, where on your body they show up, and how severe they are. Also note if any other factors could be contributing — illness, stress, sleep changes, or disruptions in routine.

A simple notes app, symptom diary, or photo log works well. Photos are especially helpful, because hives often disappear before you can get to an appointment. Bringing this documentation helps your care team spot patterns you might miss.

Taking the Next Step

Type 1 diabetes and chronic hives both involve the immune system, which may explain why they sometimes happen together — but one doesn’t directly cause the other. Distinguishing chronic hives from insulin device-related skin issues, understanding how treatments affect your blood sugar, and tracking your symptoms can help you work more effectively with your healthcare team.

You can start logging your symptoms and taking photos to share with your care team. If you haven’t been tested for thyroid problems, ask your healthcare provider whether it makes sense given your history. Additionally, if you’re prescribed steroids for a skin flare, reach out to your endocrinologist right away about short-term insulin adjustments. Your specialist team can give you personalized advice based on your specific situation and help you manage both conditions together.

Join the Conversation

On MyChronicHivesTeam, people share their experiences with chronic hives, get advice, and find support from others who understand.

Have you ever experienced unexplained hives since your diabetes diagnosis? Let others know in the comments below.