What is the evaluation and treatment of Hashimoto's (Hashimoto's thyroiditis) thyroiditis?

From the Guidelines

Hashimoto's thyroiditis is an autoimmune disorder that requires evaluation through blood tests measuring thyroid function and treatment with synthetic thyroid hormone replacement, typically starting at 25-50 mcg daily or 1.6 mcg/kg body weight, with dose adjustments based on TSH levels measured every 6-8 weeks until stabilized, as recommended by the most recent guidelines 1.

Evaluation of Hashimoto's Thyroiditis

The evaluation of Hashimoto's thyroiditis involves:

• Blood tests measuring thyroid function (TSH, free T4, free T3) and thyroid antibodies (anti-TPO and anti-thyroglobulin) 1
• Physical examination for thyroid enlargement

Treatment of Hashimoto's Thyroiditis

The treatment of Hashimoto's thyroiditis primarily involves:

• Synthetic thyroid hormone replacement with levothyroxine (brand names include Synthroid, Levoxyl), typically starting at 25-50 mcg daily for mild cases or 1.6 mcg/kg body weight, with dose adjustments based on TSH levels measured every 6-8 weeks until stabilized 1
• Annual TSH testing once stable
• The medication should be taken on an empty stomach 30-60 minutes before breakfast or 3-4 hours after the last meal of the day
• Certain medications and supplements (calcium, iron, antacids) should be taken at least 4 hours apart from levothyroxine to avoid interference with absorption

Considerations for Treatment

• For patients without risk factors, full replacement can be estimated using ideal body weight for a dose of approximately 1.6 mcg/kg/d 1
• For those older than age 70 years and/or frail patients with multiple comorbidities, consider titrating up from a lower starting dose of 25-50 mg 1
• Elevated TSH can be seen in the recovery phase of thyroiditis, and in asymptomatic patients with FT4 that remains in the reference range, it is an option to monitor before treating to determine whether there is recovery to normal within 3-4 weeks 1

Lifestyle Modifications

Lifestyle modifications including stress management, adequate sleep, and anti-inflammatory diet may help manage symptoms, though they don't replace medication. Some patients may benefit from combination therapy adding T3 (liothyronine/Cytomel) if symptoms persist despite normal TSH on levothyroxine alone. Treatment is typically lifelong, as the condition causes progressive thyroid damage.

From the FDA Drug Label

As pituitary thyroid-stimulating hormone (TSH) suppressants, in the treatment or prevention of various types of euthyroid goiters, including thyroid nodules, subacute or chronic lymphocytic thyroiditis (Hashimoto's) and multinodular goiter

• The evaluation and treatment of Hashimoto's thyroiditis involves the use of thyroid hormone drugs, such as liothyronine, as replacement or supplemental therapy in patients with hypothyroidism of any etiology, including Hashimoto's thyroiditis.
• The treatment goal is to normalize the serum TSH level and maintain euthyroidism.
• Levothyroxine can also be used to treat Hashimoto's thyroiditis, with the dosage adjusted based on the patient's serum TSH levels and clinical response 2 3.

From the Research

Evaluation of Hashimoto's Thyroiditis

• Hashimoto's thyroiditis is characterized by thyroid-specific autoantibodies and is one of the commonest autoimmune disorders 4.
• The diagnosis of Hashimoto's thyroiditis is clinical and based on clinical characteristics, positivity to serum antibodies against thyroid antigens, and lymphocytic infiltration on cytological examination 4.
• The disease is related to an interaction among genetic elements, environmental factors, and epigenetic influences, with cellular and humoral immunity playing a key role in its development 4.

Treatment of Hashimoto's Thyroiditis

• The mainstream of treatment is based on the management of hypothyroidism with substitution therapy, typically levothyroxine 4, 5.
• Lifelong levothyroxine substitution is required in most cases of patients with Hashimoto's thyroiditis 5.
• Careful supplementation of possible deficiencies, such as iodine, selenium, and vitamin D, is recommended for the dietary management of Hashimoto's thyroiditis patients 5.
• A diet low in gluten may be beneficial for Hashimoto's thyroiditis patients with or without celiac disease 5.

Disease Mechanisms and Associations

• Hashimoto's thyroiditis is characterized by lymphoplasmacytic infiltration, lymphoid follicle formation with germinal centers, and parenchymal atrophy 4.
• The occurrence of large follicular cells and oxyphilic or Askanazy cells is frequently associated with Hashimoto's thyroiditis 4.
• A relationship between Hashimoto's thyroiditis and possible malignant transformation has been proposed, involving immunological/hormonal pathogenic links 4.
• Hashimoto's thyroiditis is frequently associated with autoimmune diseases of other organs, such as vitiligo, Addison's disease, and diabetes mellitus type 1 6.

Patient Outcomes and Symptoms

• Patients with Hashimoto's thyroiditis often experience multiple extrathyroidal symptoms, including digestive, endocrine, neuropsychiatric, and mucocutaneous symptoms 7.
• Elevated thyroid antibodies are inversely associated with health-related life quality and positively associated with inflammation and multiple extrathyroidal symptoms 7.
• Serum antithyroid peroxidase antibody levels decline in most patients with Hashimoto's thyroiditis who are taking levothyroxine, but may not become negative in all patients 8.