Riedel’s thyroiditis is a rare type of chronic thyroiditis in which scar tissue replaces thyroid tissue. It can cause symptoms such as breathing problems, difficulty swallowing, and hoarseness.

Riedel’s thyroiditis is also known as:

  • Riedel struma
  • ligneous struma
  • chronic invasive fibrous thyroiditis

The condition can affect the thyroid gland and the surrounding area. As fibrotic tissue, or scar-like tissue, replaces the thyroid tissue, it can lead to symptoms such as dyspnea, dysphagia, and hoarseness.

Read on to learn more about the symptoms of Riedel’s thyroiditis. This article also looks at causes, how doctors diagnose the condition, treatment options, and more.

Symptoms of Riedel’s thyroiditis can include:

It can also lead to hypoparathyroidism, hypothyroidism, and Horner syndrome.

Hypoparathyroidism

Hypoparathyroidism can occur when the parathyroid glands do not produce enough parathyroid hormone.

Symptoms can include:

  • numbness or tingling (paresthesias) affecting the fingers, toes, or lips
  • muscle cramps, aches, or spasms
  • fatigue
  • weakness
  • headaches
  • dry skin
  • brittle nails
  • patchy hair loss

Hypothyroidism

Hypothyroidism, or an underactive thyroid, occurs when the thyroid gland does not make enough thyroid hormone.

Symptoms can include:

  • cold intolerance
  • fatigue
  • unexplained weight gain
  • muscle and joint pain
  • dry skin or hair
  • slow heart rate

Horner syndrome

Horner syndrome occurs when something affects the sympathetic nerve supply to the eye. This can happen if Riedel’s thyroiditis affects the sympathetic trunk, which runs from the skull to the coccyx.

Symptoms can include:

  • upper eyelid drooping
  • lower eyelid swelling
  • smaller pupils
  • sinking of the eyeball
  • different iris colors

Riedel’s thyroiditis is a rare condition that occurs when chronic inflammation and scarring of the thyroid gland merges with surrounding structures such as the windpipe (trachea) and muscle.

The exact cause of Riedel’s thyroiditis is unclear. It may be related to an autoimmune condition, particularly as some people with the condition have certain antibodies.

The condition may also be related to the immune protein immunoglobulin G4 (IgG4).

More research is necessary to better understand the possible causes of Riedel’s thyroiditis.

To assist with reaching an accurate diagnosis, a doctor may begin by asking questions about symptoms and performing a physical examination.

Tests that can help reach an accurate diagnosis include:

In some cases, due to the firmness of the thyroid gland in Riedel’s thyroiditis, fine needle aspiration may not be possible. In these cases, a doctor may recommend a biopsy in a surgical setting instead.

Your doctor can provide more information about what tests they recommend and what they involve. They may refer you to an endocrinologist, a hormone specialist.

As Riedel’s thyroiditis is a rare condition, there is no standard treatment.

Glucocorticoids can help manage inflammation, particularly in the early stages of the condition.

A selective estrogen receptor modulator (SERM) medication called tamoxifen can help block hormone signals, which can be useful in treating Riedel’s thyroiditis.

Mycophenolate mofetil, an immunosuppressive agent with anti-fibrotic properties, may also help.

Doctors may also recommend surgery. Subtotal or partial thyroidectomy can help relieve compressive symptoms. However, there is a risk of complications, so doctors may only recommend minimal surgery where absolutely necessary.

Your doctor can provide more information about the treatments they recommend, including the benefits and risks, to help you create a suitable treatment plan.

Riedel’s thyroiditis is a very rare condition. It affects around 1.06 in every 100,000 people.

Possible complications of Riedel’s thyroiditis include:

  • respiratory failure
  • venous thrombosis, where a blood clot blocks the vein
  • Horner syndrome
  • hypoparathyroidism
  • complications as a result of surgery, such as damage to the recurrent laryngeal nerve

Seeking medical advice as soon as there are concerns about Riedel’s thyroiditis may help to reduce the likelihood of complications.

Riedel’s thyroiditis is a rare condition that can cause breathing difficulty, swallowing problems, and hoarseness. The exact cause is unclear, but symptoms develop due to fibrotic tissue replacing the thyroid tissue, causing hardening of the thyroid.

Doctors may order imaging tests such as ultrasounds, CT scans, and PET scans to help diagnose the condition. Fine needle aspiration or biopsy may be necessary to confirm the diagnosis.

There is no single treatment for Riedel’s thyroiditis. Doctors may recommend medications such as glucocorticoids, tamoxifen, and mycophenolate mofetil. Surgery can also help, though there are risks of complications.