History
Patient presentation depends on the etiology of the thyrotoxicosis. Subacute granulomatous thyroiditis is associated with an acute, viruslike illness with fevers and myalgias with a painful thyroid. A recent birth signals postpartum thyroiditis. Often, thyrotoxicosis caused by subacute lymphocytic thyroiditis, postpartum thyroiditis, or the surreptitious use of thyroid hormone is symptomatic because of persistent tachycardia, nervousness, and weight loss. Symptoms of thyrotoxicosis that persist for longer than 2 months are probably not caused by subacute thyroiditis.
Subacute granulomatous thyroiditis
Some patients experience a flulike prodromal episode 1-3 weeks prior to the onset of clinical disease. The natural course of the disease can be divided into the following 4 phases, which usually unfold over a period of 3-6 months:
-
Acute phase - Lasts 3-6 weeks and presents primarily with pain; symptoms of hyperthyroidism also may be present
-
Transient asymptomatic and euthyroid phase - Lasts 1-3 weeks
-
Hypothyroid phase - Lasts from weeks to months; it may become permanent in 5-15% of patients
-
Recovery phase - Characterized by normalization of thyroid structure and function
The diagnosis is made based on clinical findings. Prodromal flulike symptoms (fevers, myalgia, malaise) or known infectious disease, such as pharyngitis, measles, mumps, Q fever, or typhoid fever, may occur. In young patients, de Quervain thyroiditis may develop following an episode of Henoch-Schönlein purpura. However, a history of prodromal symptoms often cannot be obtained.
Local symptoms
Local symptoms can include the following:
-
Dysphagia
-
Hoarseness (uncommon)
-
Pain over the thyroid area that is gradual or of sudden onset
Pain is the presenting symptom in over 90% of cases. It usually involves both lobes of the thyroid; in 30% of cases, it starts on one side and then migrates contralaterally within a few days. While the pain may be limited to the region of the thyroid, it may also involve the upper neck, throat, jaw, or ears. Some patients may first consult an otolaryngologist.
The pain may be so severe that the patient cannot tolerate palpation of the neck. The pain is most commonly bilateral. Occasionally, it may be unilateral, beginning in one lobe and spreading to the opposite side (creeping thyroiditis). Coughing, swallowing, or even tightening a necktie aggravates pain.
Constitutional symptoms
Constitutional symptoms (often absent) can include the following:
-
Fever
-
Malaise
-
Anorexia
-
Fatigue
-
Muscle aches
Symptoms of hyperthyroidism
Hyperthyroidism is usually is mild, becoming severe only in rare cases. The symptoms are transient, typically lasting 3-6 weeks. Symptoms of hyperthyroidism occurring in the acute phase of subacute granulomatous thyroiditis include the following:
-
Tachycardia
-
Tremulousness
-
Heat intolerance
-
Sweating
-
Nervousness
-
Warm skin
-
Frequent bowel movements
Symptoms of hypothyroidism
Symptoms of hypothyroidism occur in the late phase of the disease in up to 50% of cases. The hypothyroidism is most often mild or moderate. It is also transient, lasting weeks to months in 90-95% of cases. Symptoms of hypothyroidism occurring during the second phase of subacute granulomatous thyroiditis include the following:
-
Fatigue
-
Dry skin
-
Lethargy
-
Eyelid swelling
-
Cold intolerance
-
Constipation
Atypical symptoms
Atypical presentations of subacute granulomatous thyroiditis—that is, extremely rare symptoms that have been documented as case reports—can include the following:
-
Thyroid storm [22]
-
Fever of unknown origin
-
Painless subacute granulomatous thyroiditis
-
Occult de Quervain disease mimicking giant cell arteritis
-
Prominent prostration and confusion lasting several weeks
-
Solitary painless nodule
Subacute lymphocytic thyroiditis
This form of subacute thyroiditis is associated with a painless, firm enlargement of the thyroid gland and high thyroid hormone levels. Only suspicion by the clinician and use of radioactive iodine uptake measurement can distinguish Graves hyperthyroidism from subacute lymphocytic thyroiditis.
Subacute postpartum thyroiditis
This condition is associated with a painless, firm enlargement of the thyroid gland and high thyroid hormone levels. The identifying feature is its occurrence 1-6 months after childbirth. Patients may report lack of sleep, nervousness, fatigue, and easy weight loss. [3, 2]
Autoimmune hyperthyroidism from Graves disease can also occur for the first time postpartum and must be distinguished from postpartum thyroiditis. Both conditions are associated with high antithyroid antibody titers.
Physical Examination
All conditions described are associated with thyrotoxicosis and the signs and symptoms of hypermetabolism. None of the forms of subacute thyroiditis is associated with the thyroid eye disease observed primarily with Graves hyperthyroidism. The presence of bilateral proptosis and chemosis with high thyroid hormone levels and goiter is highly suggestive of Graves disease.
Subacute granulomatous thyroiditis
Patients often present with an acute, viruslike illness characterized by high, spiking fever; malaise; myalgia; fatigue; and prostration.
Thyroid pain is usually symmetrical. In 30% of cases, however, it starts on one side and then migrates contralaterally within a few days. While the pain may be limited to the region of the thyroid, it may also involve the upper neck, throat, jaw, or ears. In many patients, the pain is so severe that he or she cannot tolerate palpation of the neck. The pain may be intense enough to prevent the swallowing of saliva, liquids, and food.
Thyroid enlargement, however, is usually symmetrical and mild, occasionally with areas of localized firmness. Erythema and hyperesthesia of the overlying skin may be present at the onset of severe cases. Cervical lymphadenopathy is uncommon. Lid retraction is rare, and exophthalmos does not occur.
Thyroid hormone levels are often extremely elevated, resulting in marked signs and symptoms of thyrotoxicosis. Cases of lesser severity also exist, and the etiology may be confusing.
Symptoms of hyperthyroidism occurring in the acute phase of subacute granulomatous thyroiditis include the following:
-
Tachycardia
-
Tremulousness
-
Heat intolerance
-
Sweating
-
Nervousness
-
Warm skin
-
A rapid relaxation phase of tendon reflexes
Subacute lymphocytic thyroiditis
Patients present with a nonpainful thyroid enlargement and elevated thyroid hormone levels. This condition must be distinguished from Graves thyrotoxicosis because antithyroid medication is not indicated in this temporary condition.
Subacute postpartum thyroiditis
Patients present 1-6 months postpartum with painless thyroid enlargement and elevated thyroid hormone levels. Sometimes, distinguishing between the usual postpartum changes in physiology and additional thyroid pathology is difficult. [3, 2]
-
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.
-
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.
-
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.
-
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 |
||||
