Thyroiditis: An Integrated Approach LORI B. SWEENEY, MD, Virginia Commonwealth University Health System, Richmond, Virginia CHRISTOPHER STEWART, MD, Bayne-Jones Army Community Hospital, Fort Polk, Louisiana DAVID Y. GAITONDE, MD, Dwight D. Eisenhower Army Medical Center, Fort Gordon, Georgia Thyroiditis is a general term that encompasses several clinical disorders characterized by inflammation of the thyroid gland. The most common is Hashimoto thyroiditis; patients typically present with a nontender goiter, hypothyroid- ism, and an elevated thyroid peroxidase antibody level. Treatment with levothyroxine ameliorates the hypothyroid- ism and may reduce goiter size. Postpartum thyroiditis is transient or persistent thyroid dysfunction that occurs within one year of childbirth, miscarriage, or medical abortion. Release of preformed thyroid hormone into the bloodstream may result in hyperthyroidism. This may be followed by transient or permanent hypothyroidism as a result of depletion of thyroid hormone stores and destruction of thyroid hormone–producing cells. Patients should be monitored for changes in thyroid function. Beta blockers can treat symptoms in the initial hyperthyroid phase; in the subsequent hypothyroid phase, levothyroxine should be considered in women with a serum thyroid-stimulating hormone level greater than 10 mIU per L, or in women with a thyroid-stimulating hormone level of 4 to 10 mIU per L who are symptomatic or desire fertility. Subacute thyroiditis is a transient thyrotoxic state characterized by anterior neck pain, suppressed thyroid-stimulating hormone, and low radioactive iodine uptake on thyroid scanning. Many cases of subacute thyroiditis follow an upper respiratory viral illness, which is thought to trigger an inflammatory destruction of thyroid follicles. In most cases, the thyroid gland spontaneously resumes normal thyroid hormone production after several months. Treatment with high-dose acetylsalicylic acid or nonsteroidal anti-inflammatory drugs is directed toward relief of thyroid pain. (Am Fam Physician. 2014;90(6):389-396. Copyright © 2014 American Academy of Family Physicians.) CME This clinical content hyroiditis is a general term that measured. Second, the laboratory test result conforms to AAFP criteria refers to inflammation of the thy- should be interpreted within the context of for continuing medical education (CME). See roid gland and encompasses sev- the medical status of the patient. Patients CME Quiz Questions on eral clinical disorders. The family recovering from recent illness or those tak- page 372. Tphysician will most commonly diagnose ing drugs such as glucocorticoids or opiates Author disclosure: No rel- thyroiditis because of abnormal results on may have suppressed TSH, but free thy- evant financial affiliations. thyroid function testing in a patient with roid hormone levels will be normal or low. ▲ Patient information: symptoms of thyroid dysfunction or anterior Third, the degree of hyperthyroidism and A handout on this topic neck pain. The diagnosis of chronic autoim- the severity of symptoms should be consid- is available at http:// mune thyroiditis (Hashimoto thyroiditis) is ered. Patients with overt hyperthyroidism familydoctor.org/family usually straightforward. Patients typically (suppressed TSH and elevated free thyroid doctor/en/diseases- conditions/thyroiditis.html. present with a nontender goiter, symptoms hormone levels) and significant symptoms of hypothyroidism, and elevated thyroid can be treated with beta blockers, regardless peroxidase (TPO) antibody level. However, a of the etiology. Fourth, the physician should diagnostic dilemma occurs when the patient attempt to differentiate between Graves dis- presents with thyroid-stimulating hormone ease and other forms of thyroiditis, because (TSH) suppression. The natural history of patients with Graves disease are candidates postpartum, silent, or subacute thyroiditis for thionamide therapy. This differentiation may include a hyperthyroid or toxic phase of is best made by measuring radioactive iodine short duration, followed by transient or per- uptake on a thyroid scan. manent hypothyroidism. In the case of postpartum, silent, or sub- When hyperthyroidism does not match acute thyroiditis, the radioactive iodine the clinical picture, several steps should be uptake during the hyperthyroid phase will be taken. First, the laboratory test result should low. Most of these patients will have recovery be confirmed, and free thyroxine (T4) and of euthyroidism, but some may benefit from free triiodothyronine (T3) levels should be treatment aimed at relieving symptoms of SeptemberDownloaded 15, from 2014 the American◆ Volume Family 90, NumberPhysician website6 at www.aafp.org/afp.www.aafp.org/afp Copyright © 2014 American Academy of FamilyAmerican Physicians. Family For the Physician private, noncom 389- mercial use of one individual user of the website. All other rights reserved. Contact [email protected] for copyright questions and/or permission requests. Thyroiditis hyperthyroidism or hypothyroidism, provided they are ing less common forms. Table 2 summarizes drugs asso- monitored for anticipated changes in thyroid function. ciated with thyroiditis.1-8 Surveillance and clinical follow-up are necessary in all Figure 1 is an algorithm for the diagnosis of thyroiditis.9 forms of thyroiditis because of the potential for change in thyroid status. Treatment with levothyroxine may Chronic Autoimmune Thyroiditis result in iatrogenic hyperthyroidism. Chronic autoimmune thyroiditis (Hashimoto thyroid- Table 1 summarizes key aspects of thyroiditis, includ- itis) is the most common form. It is characterized by Table 1. Thyroiditis Subtypes Type Presentation Etiology Diagnosis Complications Therapy Chronic autoimmune thyroiditis Hypothyroidism; rarely thyrotoxicosis secondary to alternating Autoimmune Presence of nontender goiter; thyroid function tests; Hypothyroidism is usually Levothyroxine (Hashimoto thyroiditis, chronic stimulating and inhibiting thyroid autoantibodies elevated TPO antibody levels permanent lymphocytic thyroiditis) Presence of an elevated TPO antibody level confers risk for many types of thyroid dysfunction and is a general marker of thyroid autoimmunity; a frankly elevated TPO antibody level is more specific for Hashimoto thyroiditis Infectious thyroiditis Thyroid pain, high fever, leukocytosis, and cervical lymphadenopathy; Multiple infectious organisms, Thyroid fine-needle aspiration with Gram stain and Acute complications may include Hospitalization and treatment with intravenous (suppurative thyroiditis) focal inflammation may result in compressive symptoms such as most commonly bacterial culture; blood cultures; neck magnetic resonance septicemia and acute airway antibiotics (nafcillin plus gentamicin or a dysphonia or dysphagia; patients may assume a posture to limit Streptococcus pyogenes; imaging or computed tomography with contrast obstruction; later sequelae of third-generation cephalosporin); abscess neck extension; palpation may reveal focal or diffuse swelling Staphylococcus aureus and media; plain radiography of the lateral neck may the acute infection may include formation may necessitate surgical drainage; of the thyroid gland and the overlying skin will be warm and Pneumococcus are among reveal gas in the soft tissues; thyroid autoantibodies transient hypothyroidism or euthyroidism is generally restored after erythematous; presence of fluctuance suggests abscess formation the most common isolates are generally absent; serum thyroxine and vocal cord paralysis treatment of infection triiodothyronine levels are usually normal Postpartum thyroiditis Hyperthyroidism alone; hyperthyroidism followed by hypothyroidism; Autoimmune Thyroid function tests; elevated TPO antibody levels; Euthyroidism is generally Beta blockers can be considered for significant or hypothyroidism alone within one year of parturition low radioactive iodine uptake in the hyperthyroid achieved by 18 months, but hyperthyroid symptoms (in the hyperthyroid phase* up to 25% of women become phase); levothyroxine for symptomatic permanently hypothyroid; hypothyroidism (in the hypothyroid phase) high rate of recurrence with and for permanent hypothyroidism subsequent pregnancies Radiation-induced thyroiditis† Patients may present with thyroid pain and transient thyrotoxicosis Radiation Clinical diagnosis made in the setting of recent Hyperthyroidism generally Self-limited, but symptoms may be treated previous radiation resolves within one month with beta blockers and nonsteroidal anti- inflammatory drugs Riedel thyroiditis (fibrous Very firm goiter or compressive symptoms (dyspnea, stridor, Autoimmunity may contribute Thyroid biopsy Most patients are euthyroid, Glucocorticoids and mycophenolate thyroiditis)‡ dysphagia), which appear disproportionate to the size of to the pathogenesis approximately 30% are (Cellcept); tamoxifen may work by inhibiting the thyroid; hypocalcemia may occur as a result of fibrotic hypothyroid fibroblast proliferation transformation of the parathyroid glands Silent thyroiditis (silent Hyperthyroidism alone; hyperthyroidism followed by hypothyroidism; Autoimmune Thyroid function tests; elevated TPO antibody levels; Euthyroidism is generally achieved Beta blockers can be considered for significant sporadic thyroiditis, painless or hypothyroidism alone low radioactive iodine uptake in the hyperthyroid by 18 months, but up to 11% of hyperthyroid symptoms (in the hyperthyroid sporadic thyroiditis, subacute