In this article:

It may sound like a stretch to correlate your allergies to your thyroid gland. After all, your thyroid gland is generally more preoccupied with other matters, such as regulating your metabolism and growth and development. Yet, when you look at what causes both Hashimoto's thyroiditis and allergies, the link between the two is surprisingly easy to see. Let's dive into how the two are related and what you can do to manage both conditions.

‍

Hashimoto's thyroiditis, also known as autoimmune thyroid disease, is a condition where your immune system attacks healthy tissues in your thyroid gland. Our immune systems are highly sophisticated—they can detect when even the smallest foreign invaders are in our bodies and can mount an attack to eradicate invaders to keep our bodies healthy. But sometimes, our immune systems go into overdrive and attack even healthy tissue. The over-responsiveness or hyperactivity of the immune system is what causes autoimmune disease.

In Hashimoto's, the immune system attacks healthy thyroid cells, leading to chronic inflammation over time. When your thyroid is continually inflamed, it can cause the organ to be less effective at doing what it is supposed to do, making thyroid hormones. Thus, Hashimoto's can cause the thyroid gland to lose the ability to produce enough hormone to support the body's metabolic needs.

‍

‍

An over-responsiveness of the immune system also causes allergies. Usually, a foreign particle enters the body. Then the immune system responds by creating antibodies to recognize and fight these foreign substances in the future. When the body recognizes them after first exposure, it releases several chemicals into the body, including histamine, that cause specific symptoms.

Allergens enter your body through your eyes, nose, mouth, skin, and digestive tract, and common allergens include:

• Dust

• Pollen

• Bee or wasp venom

• Dander

• Mold

• Food proteins (like cow's milk, egg, peanut, soy, and almond)

• Chemicals (like those found in drugs, cosmetics, etc.)

Everyone responds to allergens differently. Some people are not sensitive at all, whereas others are highly sensitive. The body's response can range from allergic rhinitis (hay fever) to anaphylaxis, where your immune response is so severe that it blocks your airway and drops your blood pressure. Anaphylaxis can be life-threatening and requires immediate medical attention.

Most people with allergies have allergic rhinitis. Symptoms of allergic rhinitis include:

• Sneezing

• Runny nose

• Itchy eyes, nose, and roof of the mouth or the back of the throat

• Red, swollen eyes (also called allergic conjunctivitis)

Sometimes, people can also develop hives when they contact something to which they are particularly allergic, such as hay or pet dander.

‍

Both conditions result from an overactive immune system. Given this shared etiology of over-responsiveness of the immune system, studies show that people with Hashimoto's are more likely than the general population to suffer from allergies and vise versa. 

One study found that of the general population, only 1.5% had Hashimoto's. However, in patients with allergic rhinitis, 16.3% of them had Hashimoto's. Another study shows that people with autoimmune hyperthyroidism, or Graves' disease, are also more likely to have chronic allergies than the general population. The numbers are even higher for people with Graves' disease, where 42.9% of people with Graves' have allergic rhinitis.

Other allergic processes, like eczema and food allergies, are also likely to occur in people with autoimmune thyroiditis. 

Because there is a higher incidence of allergies in people with autoimmune thyroid disease, it may be beneficial to find out if you have allergies because exposure to allergens can further agitate your immune system. Similarly, people who have allergies may want to be mindful of thyroid disease, especially if they have other autoimmune conditions like rheumatoid arthritis.

‍

An essential part of managing Hashimoto's is keeping your immune system in check. If you do have allergies, it is crucial to avoid any triggers as much as possible. When your immune system becomes too overactive, it can worsen thyroid inflammation and cause frustrating allergy symptoms. 

Aside from causing allergy symptoms, too much activity from your immune system can also cause you to have a Hashimoto's flare-up. When you have a flare-up, your thyroid symptoms worsen due to some sort of trigger. For many people, it is stress or illness, but allergies can cause a flare-up too. 

Avoidance allergens

Avoiding allergens is the best way not to have allergy symptoms. However, most allergens are unavoidable. To decrease your chances of having allergy symptoms, the American Academy of Allergy, Asthma, and Immunology recommends: 

• Steering clear of animals that make you allergic. If that is not feasible, make sure to wash your hands and clothes thoroughly after coming in contact with them.

• Track pollen counts to see when they are at their peak and keep indoors as much as possible during high pollen count times. Also, keep your windows and doors closed during these times.

• Wash your bedding frequently and change air filters regularly.

• Wear sunglasses or glasses to keep pollen out of your eyes.

• Keep your home free of mold by regularly cleaning (especially wet areas like your bathroom and kitchen) and use HEPA air filters on your vacuum. 

‍

Lower inflammation in the body

You can make changes to your diet and lifestyle to lower inflammation in the body. Some of these changes may include identifying and removing dietary and environmental triggers, eating a nutrient-dense diet, repairing leaky gut, managing stress, getting adequate sleep, and moving your body regularly. 

Try natural antihistamines

Histamine is a protein released in the body in response to an allergen that causes inflammation, redness, and irritation. Some herbs, like nettle leaf, butterbur, mangosteen, or ginger, may reduce these histamine reactions. 

‍

Take over-the-counter allergy medications

Over-the-counter medications are the first-line treatment for chronic rhinitis and are highly effective. Intranasal corticosteroids are the most successful at treating allergic rhinitis. However, people also find success using antihistamines that you commonly see at the supermarket, including:

• Zyrtec®

• Allegra®

• Xyzal®

• Claritin®

‍

Limited offer

20% off your first Thyroid Test

Test your thyroid levels from home and know your levels in days

Use code GETBETTER at checkout

Use code

Oops! Something went wrong while submitting the form.

Before you start a new allergy medication, measure your thyroid hormone levels with a thyroid blood test. Some allergy medications may come with a warning that people with a thyroid condition should not take them. However, this is usually only applicable for people whose thyroid is not stable.

As seasons change, many people struggle with allergy symptoms. To keep your symptoms in check and avoid any complications, talk to your thyroid doctor to determine if a daily allergy medication is safe for your thyroid.