Snapshot A 32-year-old G0P1001 woman and her 4-week old newborn come to the clinic for a routine newborn checkup. The mother complains of irritation and palpitations but denies other concerns. A physical examination of the newborn is unremarkable and he is tracking well within his growth curves. A thyroid function test of the mother shows low levels of TSH. Introduction Introduction thyroiditis includes a diverse group of disorders that is characterized by some form of thyroid inflammation all the conditions presented here are not associated with thyroid pain or tenderness clinical syndromes silent thyroiditis postpartum thyroiditis Riedel thyroiditis ETIOLOGY Pathogenesis association, to various degrees, with chronic autoimmune thyroiditis (Hashimoto disease) Silent Thyroiditis Characterized by transient hyperthyroidism (followed sometimes by hypothyroidism) and then recovery; considered a variant form of chronic autoimmune thyroiditis (Hashimoto’s thyroiditis) risk factors positive family history of thyroid autoimmune disease lithium therapy cessation of glucocorticoids Presentation frequently incidentally detected by routine thyroid testing hyperthyroid symptoms developing over 1-2 weeks and lasting 2-8 weeks weakness, fatigue, irritability, palpitations, stare/lid retraction, tachycardia, and tremor the thyroid gland is not painful/tender may be followed by hypothyroidism for 2-8 weeks (usually clinically mild or asymptomatic) cold intolerance, constipation, or fatigue Studies low serum TSH moderately elevated serum free T4 normal or slightly elevated T3 Treatment no treatment is needed for most patients symptomatic hyperthyroid phase beta-blocker (e.g., propranolol) for prevention of atrial-fibrillation symptomatic hypothyroid phase levothyroxine Postpartum Thyroiditis Autoimmune destructive thyroiditis within one year after delivery characterized by either 1) transient hyperthyroidism 2) transient hypothyroidism or 3) transient hypothyroidism followed by hypothyroidism and then recovery most women recover within one year but about 1 in 5 women will develop permanent hypothyroidism risk factors type 1 diabetes mellitus prior history of postpartum thyroiditis positive antithyroid peroxidase antibodies Presentation presentation can be similar to that in painless thyroiditis, however, many of the symptoms are often attributed to breastfeeding or newborn stress hyperthyroid symptoms developing over 1-2 weeks and lasting 2-8 weeks weakness, fatigue, irritability, palpitations, stare/lid retraction, tachycardia, and tremor the thyroid gland is not painful/tender may be followed by hypothyroidism for 2-8 weeks (usually clinically mild or asymptomatic) cold intolerance, constipation, or fatigue Studies high or high-normal serum free T4 and T3 low serum TSH high serum antithyroid peroxidase antibody Treatment asymptomatic patients should be monitored via regular thyroid function tests symptomatic hyperthyroidism phase beta blockers (propranolol is preferred in women who are breastfeeding) symptomatic hypothyroid phase levothyroxine Riedel Thyroiditis An invasive fibrotic process associated with a mononuclear cell inflammation that extends into the perithyroidal soft tissue may occur as part of IgG4-related systemic disease association with chronic autoimmune thyroiditis (Hashimoto thyroiditis) Presentation slowly growing painless goiter that is “stony” hard anterior neck pressure dysphagia hoarseness hypoparathyroidism symptoms of hypothyroidism (e.g., cold intolerance, constipation, or fatigue) Imaging ultrasonography will demonstrate heterogeneous hypoechoic lesions with the absence of vascular flow in the Riedel’s regions Studies laboratory tests normal serum TSH serum calcium and phosphorus for identification of coexist hypoparathyroidism pathology resected thyroid tissue demonstrates hard, white, avascular tissue histology shows intense infiltration of lymphocytes, plasma cells, neutrophils, and eosinophils early in the disease Treatment treat hypothyroidism if present with levothyroxine glucocorticoids and tamoxifen to reduce progression surgical resection if tracheal or esophageal compression is present Complications recurrent pneumonia due to bronchial compression hypoparathyroidism