Approach Considerations
The treatment of subacute thyroiditis is generally supportive to reduce the symptoms of thyrotoxicosis and to control neck pain in the setting of subacute granulomatous thyroiditis. Because no new hormone is being made, antithyroid medications are not effective in these conditions. Although the abnormal thyroid levels are temporary, emotional support is often necessary. [2, 3]
Patients are often dehydrated from thyrotoxicosis; encourage all patients to drink 6-8 cups per day of noncaffeinated fluids.
Surgical care is almost never recommended for subacute thyroiditis. In rare cases, surgery is recommended for patients who have frequent recurrences of thyrotoxicosis from subacute lymphocytic thyroiditis or recurrent pain from subacute granulomatous thyroiditis. [46]
Inpatient care
Inpatient care is only recommended in the rare cases in which severe symptomatic hyperthyroidism is present.
Diet
Avoiding high-dose iodine supplements, such as those found in seaweed tablets, during and after an episode of subacute thyroiditis is important. Inflammation appears to prevent the thyroid from escaping the iodine-induced Wolff-Chaikoff suppression of thyroid hormone synthesis. Consequently, patients are likely to become hypothyroid when ingesting large amounts of iodine.
Activity
No limitation in activity is necessary, but patients may experience tachycardia with exercise. Good hydration and beta-blocker therapy should allow patients with subacute thyroiditis–caused thyrotoxicosis to exercise normally.
Consultations
Generally, all patients with thyrotoxicosis should be referred to an endocrinology specialist. Distinguishing between the causes of thyrotoxicosis is important, because the therapies are very different.
Prevention
No medical intervention is known to prevent any form of subacute thyroiditis. Recurrent episodes in patients with recurrent subacute thyroiditis with severe symptoms can be prevented with thyroidectomy.
Pharmacologic Therapy
Pain in subacute granulomatous thyroiditis
Management of subacute granulomatous thyroiditis is directed towards 2 problems: pain and thyroid dysfunction.
Thyroid pain in this condition can be extreme (although some patients with mild pain require no treatment). Nonsteroidal anti-inflammatory drugs (NSAIDs)—such as such as ibuprofen (800-1200 mg/day in divided doses) and naproxen (1-1.5 g/day in divided doses)—are the first-line agents used for pain treatment, although large dosages are typically needed. Treatment can be tapered as allowed by the patient's pain.
Most NSAIDs provide comparable efficacy in pain relief. Avoid high-dose aspirin because, in some circumstances, aspirin can competitively displace thyroid hormone from its binding protein and increase the free, or bioactive, fraction of thyroid hormone, which can make patients feel more thyrotoxic. Analgesic therapy can usually be stopped after 2-6 weeks.
In extreme cases, stronger pain medications, including narcotic analgesics, are indicated for a brief period of 2-3 weeks. In the most extreme cases, high-dose steroids (eg, prednisone 40-60 mg/day) must be administered. Corticosteroids are highly effective, and relief of pain is quick and dramatic. If pain and tenderness do not disappear within 72 hours after the start of therapy, the diagnosis of subacute thyroiditis should be questioned. Symptoms of thyrotoxicosis are also alleviated with glucocorticoids.
Research indicates that prednisolone 15 mg/day with a taper of 5 mg every 2 weeks is a safe and effective means of quickly reducing pain. In a study of prednisolone use by Kubota et al, most patients had resolution of symptoms by 6-8 weeks, although the longest period of therapy was 40 weeks. [20] A study by Sato et al found that prednisolone (mean dose 15 mg/day) more quickly resolved symptoms of subacute thyroiditis than did the nonsteroidal anti-inflammatory drug loxoprofen (mean dose 180 mg/day) (7 vs 21 days to resolution, respectively). However, in the report, of 42 patients treated with either medication, the two drugs were comparable with regard to time to normalization of thyroid function. [47]
Hypothyroidism
The hypothyroid phase in subacute thyroiditis is usually mild and transient, and typically it does not require treatment. However, if symptoms are present or the TSH level is elevated, the patient needs replacement therapy with levothyroxine. Depending on the level of TSH, the starting dose can be 25-100 mcg/day; it is adjusted for normalization of TSH. Usually, the hypothyroid stage lasts 2-3 months, but some authors recommend treatment for as long as 6 months, followed by discontinuation of the drug and monitoring of TSH levels.
In rare cases, the hypothyroidism becomes permanent, with the patient requiring lifelong replacement therapy.
Thyroid hormone levels in subacute thyroiditis
The release of preformed hormone cannot be stopped in the destructive phase. In patients with very high levels of thyroid hormone, ipodate may be administered to inhibit the conversion of T4 to the more active form of thyroid hormone, T3. An ipodate dose of 1000 mg in 2 divided doses daily usually provides a rapid reduction in T3 and in thyrotoxic symptoms.
Peripheral manifestations of thyrotoxicosis
Patients often find great relief from tachycardia, palpitations, anxiety, and tremor with beta-blocker therapy. Beta-blockers may be used if symptoms of adrenergic stimulation are troublesome. Propranolol is generally recommended because of its central nervous system (CNS) effects; it also has the theoretical advantage of inhibiting conversion of T4 to T3 at higher doses. Beta blockade can usually be withdrawn in 2-6 weeks.
Exercise caution with the initial dose of propranolol; patients may become hypotensive, because they are often dehydrated from a decrease in the oral intake of fluids and increased perspiration from thyrotoxicosis. Beta-1 selective agents (metoprolol or atenolol) have more convenient dosing and are better tolerated.
Monitoring
All forms of subacute thyroiditis
Patients should be seen every 4 weeks for reassurance and for measurement of thyroid hormone levels. Occasionally, patients have relapses of the thyrotoxic phase and experience persistent symptoms. Monitor for the subsequent hypothyroid phase and treat with levothyroxine if patients are symptomatic. [48]
Subacute granulomatous thyroiditis
Patients usually recover completely from subacute granulomatous thyroiditis. The episodes rarely recur. Generally, patients are not prone to other thyroid disease and do not need long-term follow-up.
Subacute lymphocytic and subacute postpartum thyroiditis
These conditions are sometimes associated with chronic thyroiditis. Postpartum thyroiditis usually recurs after each pregnancy. Patients should be observed routinely every 6-12 months for the development of goiter or hypothyroidism from chronic thyroiditis.
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Three multinucleated, giant cell granulomas observed in a fine-needle aspiration biopsy of the thyroid; from a patient with thyrotoxicosis resulting from subacute granulomatous thyroiditis.
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Absence of iodine-123 (123I) radioactive iodine uptake in a patient with thyrotoxicosis and lymphocytic (subacute painless) thyroiditis. Laboratory studies at the time of the scan demonstrated the following: thyroid-stimulating hormone (TSH), less than 0.06 mIU/mL; total thyroxine (T4), 21.2 mcg/dL (reference range, 4.5-11); total triiodothyronine (T3), 213 ng/dL (reference range, 90-180); T3-to-T4 ratio, 10; and erythrocyte sedimentation rate (ESR), 10 mm/h. The absence of thyroid uptake, the low T3-to-T4 ratio, and the low ESR confirm the diagnosis of lymphocytic thyroiditis.
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Example of laboratory values as they vary over the course of subacute granulomatous thyroiditis. The entire episode may evolve through all 3 phases of the disorder over a period of as long as 6 months.
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Ultrasonogram of subacute granulomatous thyroiditis. A. Transverse image. B. Sagittal image with Doppler analysis. The echotexture is very heterogeneous and hypoechoic. The vascular flow is absent in much of the affected hypoechoic regions of the lobe and much less than would be expected if this were Graves disease hyperthyroidism.
Tables
Parameters |
Stage 1 |
Stage 2 |
Stage 3 |
Stage 4 |
Symptoms |
Thyrotoxicosis |
Euthyroid |
Hypothyroid |
Euthyroid (recovery) |
T4, T3 |
Elevated |
Normal |
Decreased |
Normal |
TSH |
Decreased |
Normal |
Elevated |
Normal |
T4 = thyroxine T3 = triiodothyronine TSH = thyroid-stimulating hormone |
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