Subacute Thyroiditis: Diagnostic Difficulties and Simple Treatment

SUBACUTE THYROIDITIS: DIAGNOSTIC DIFFICULTIES AND SIMPLE TREATMENT

Joel I. Hamburger

Northland Thyroid Laboratory, Southfield, Michigan

Subacute thyroiditis (SAT) constitutes 0.8% produce the systemic manifestations of hyperthyroid of referrals to Northland Thyroid Laboratory ism, usually mild. and is one tenth as common as hyperthyroidism. The laboratory abnormalities are readily under The peak age is 30â€”SOyears, and women pre standable in terms of the underlying pathophysiology. dominated by a factor of 4.5. Two thirds of the As a consequence of the diffuse inflammation, the patients presented in typical fashion with a thyroidal uptake of radioactive iodine (RAI) is im painful tender goiter, but for one third the paired (1â€”9). The discharge of thyroid hormone presentation was atypical in that there was no elevates serum thyroxine values (ST4) (1â€”9). The pain, the principal complaint in most cases erythrocyte sedimentation rate (ESR) is elevated being painless goiter, thyroid nodule, or fea as a nonspecific response to inflammation (1â€”9), and tures of hyperthyroidism. Elevated erythrocyte occasionally there is an increase in the white blood sedimentation rates were found in all typical cell count (WBC) as well (3,6â€”9). patients and in 11 of 14 atypical patients. As the disease progresses the local and systemic Serum thyroxine iodide values were elevated in features decline until full recovery is realized, usually two thirds of the patients, typical and atypi within 2â€”4months. In some instances there is a cal. The radioactive iodine uptake was sub temporary hypothyroid phase (2,3) which rarely nornwl for all and responded subnormally to may prove permanent (10) . Lesser degrees of func thyroid-stimulating hormone for 24 of 27 pa tional impairment may be less rare. tients. Diagnosis of SAT is further supported The possibilities for different presentations of SAT by spontaneous resolution of complaints, goi can be anticipated if one considers the implications ter (nodule), and abnormal laboratory val of the protracted course of the illness, as well as van ues. Failure to consider the possibility of SAT ations in severity and extent of involvement, patient in the absence of neck pain may lead to errone perceptivity, and the time lapse between onset of ous diagnosis and improper therapy. Treatment illness and consultation with the physician. When with simple analgesics is satisfactory for most SAT presents without many of its cardinal features SAT patients. Evidence for permanent func there may be diagnostic difficulties. Although failure tional impairment was demonstrated for four to diagnose an acute, self-limited disorder may not patients. be serious per se, the potential for incorrect alterna tive diagnoses leading to unnecessary or improper therapy, is an important concern. Therefore, a prim Subacute thyroiditis (SAT) presumably results cipal objective of this paper is an analysis of ex from viral infection of the thyroid gland, causing an perience with SAT, emphasizing the recognition of acute exudative process which gradually regresses, the atypical presentation. Three particularly instruc eventuating generally in complete recovery. The hail tive patients will be reported in brief. mark of the acute phase of SAT is a painful, tender A secondary objective is to offer support for the goiter, the characteristic local manifestations of the inflammatory process (1â€”3). Accompanying sys temic manifestations of inflammation include low Received Oct. 24, 1972; revision accepted Aug. 31, 1973. For reprints contact: Joel I. Hamburger, Northland Thy grade fever, sweats, and malaise. Discharge of stored roid Laboratory, 20905 Greenfleld, Suite 300, Southfield, thyroid hormone by this inflammatory process may Mich.48075.

Volume 15, Number 2 81 HAMBURGER recommendation of simple analgesics and reassur ance as the treatment of choice for most patients with TABLEOF62PATIENTSWITHSUBACUTETHYROIDITIS1. AGE AND SEX SAT (1â€”3,11â€”13). Age (years) Men Women Total METHODS 2004420â€”2908830â€”394182240â€”49391250â€”59471160â€”69055Total115162 A review of the records of 62 SAT patients re ferred to the Northland Thyroid Laboratory con stitutes the basis for this report. Historical data and physical findings were recorded on all patients. White blood counts (WBC) and erythrocyte sedimentation rates (ESR) were frequently performed. The serum thyroxine iodide concentration (ST ,) was deter mined by the competitive protein-binding method TABLE 2. BY62SATCOMPLAINTS REPORTED (Abbott Laboratory kit), normal range (Northland PATIENTS Thyroid Laboratory) 3.0â€”6.5 ,@g%, expressed as iodide. For patients receiving estrogens or other Neckpain40Ear radiation13Migratingor iaw medications which might alter binding globulin con other8Goiter from one side to the centrations, a free thyroxine index was calculated swelling30Weightor neck using values for the ST, determination and the tn loss22Palpitotion20Heat iodothyronine resin uptake (Abbott Laboratory kit) intolerance19Malaise18Fever as previously described (14). A 24-hr radioactive iodine uptake value ( RAI) sweats17Tremor11Scantyor night was obtained for all patients. Standard methodology menses7Loose was used with the technical controls outlined in de bowels7Insomnia3 tail elsewhere ( 14 ) . TSH testing was done after a preliminary RAI by administering 5 units intra muscularly (Thytropar, Armour Laboratories) , a tracer capsule 8â€”10hr later, and counting 12â€”15hr symptoms which were commonly reported were not afterwards. A normal response in our laboratory is included for they are just as common with other thy an increment of at least 10% over the baseline value roid disorders, and indeed in patients without thyroid (confirmed by a study of 9 1 patients either taking disease. Symptoms other than local pain and swell thyroid hormone without evidence of thyroid disease ing result from the systemic responses to inflamma or euthyroid with marginally low baseline RAT val tion or the discharge of thyroid hormone. Distinc ues). tion between these two processes was often difficult. In the case reports ST , values in some instances For example, tachycardia, palpitation, sensation of were performed elsewhere. If the normal ranges vary warmth, sweating, and insomnia could result from from those cited above, they will be given. either or both processes. For most patients the sys temic manifestations of SAT were mild, and were RESULTS overshadowed by the local findings. More than one SAT is an uncommon disease. During a 2-year third of the patients were unaware of any thyroid period between 1970 and 1972, 5,254 patients with abnormality until it was called to their attention, thyroid disease were seen at the Northland Thyroid including eight patients who acknowledged tender Laboratory. Forty-two had SAT, for an incidence ness for the first time when the thyroid was palpated of 0.8% . During the same period there were 428 by the author. patients with hyperthyroidism for a ratio of 10 to 1. Table 3 lists the predominant considerations which Woolner reported 8 patients with Graves' disease for led to thyroid consultation. The majority of patients every one with SAT (15). were referred for either neck pain, goiter, or both. There is general agreement that most patients with The firm-to-hard nature of thyroid tissue involved SAT are between 30 and 50 years of age (5,6,11), with SAT raised the index of suspicion for cancer with women outnumbering men by 5 to 1 (5,16). when apparently solitary nodules were found. Lab Table 1 indicates that our data are consistent with oratory data frequently proved confusing to the fam these earlier observations. ily physician, particularly the apparent discrepancy Table 2 reveals the relative frequency of the more of an elevated ST, with a subnormal RAT, even prominent complaints elicited by history from SAT though local findings were the dominant considera patients. Nervousness, fatigue, and certain other tion in the referral. The patient with hair loss had an

82 JOURNAL OF NUCLEAR MEDICINE SUBACUTE THYROIDITIS

obtained in more than three fourths of the typical TABLE 3. PRINCIPAL FINDING PRECIPITATING patients but less than half of the atypical group. For REQUESTFOR THYROID CONSULTATION both groups evidence of systemic involvement on Neckpain40Painless physical examination (e.g., tachycardia, tremor, ele goiter12Thyroid vated temperature, hyperreflexia, excessive perspira nodule4Suspected hyperthyroidism3Hair tion) was less common than by history, suggesting value1Confusionloss, unexpected high5T that by the time the patients were seen in consulta with laboratory data tion the disease was already subsiding in some in Atrial fibrillation with goiter1 1 stances. An elevated white blood count was found in only 13 of 32 patients studied. However, the ESR was TABLE 4. PHYSICAL FIN ON over 30 mm/hr in 38 of 41 patients and was 23, THYROIDFirm-to-hardEXAMINATION OF THEDINGS 26, and 28 mm/hr in the remaining 3. An elevated consistency56Tenderness48Diffuse ESR was an important finding for atypical patients. Elevated ST, values were found in 37 of 58 patients. enlargement34Unilateral For many, the magnitude of the elevation was rather enlargement15Solitary nodule5Multinodular4No modest; hence the discrepancy between the frequency of elevated ST., values and the relative infrequency thyroid enlargement appreciated4 of physical findings of hyperthyroidism was more apparent than real.

ST., ordered by her physician to rule out hypothy RAI values were subnormal for all patients roidism. When a high value was reported, consulta whether typical or not. Only two patients had values tion was requested. over 5 % , one with 6% and one with 8 % . A sub Table 4 summarizes the findings on palpation of normal response to TSH (an increment of less than the thyroid. A firm-to-hard diffuse goiter was highly I 0% ) provided further confirmation of impaired characteristic although at times involvement was thyroid function. TSH tests were done on 27 patients. limited to one lobe or even a solitary nodule. The observed increments ranged from 0 to 16%, Forty of the 62 SAT patients were considered with an average of 5.2% . For only three patients typical in that the presenting complaint was neck were increments greater than 10% found (1 1, 13, pain and an enlarged, tender thyroid gland. The re and 16% ) . When the RAT was adequate for scan maiming 22 patients were considered atypical since ning, even though the response to TSH was subnor pain was not spontaneously appreciated, although mal, the pattern in most cases was one of patchy and for eight patients some tenderness was acknowledged irregular bilateral function, demonstrating foci of when the thyroid was subjected to palpation. For relatively less involved tissue in the diffusely inflamed some of these atypical patients the diagnosis was gland. For six patients with significant responses to made only retrospectively after further events clan TSH, scanning also provided evidence of impaired fled a confusing picture. thyroid function since uptake was asymmetrical and Table 5 summarizes the clinical and laboratory confined to uninvolved tissue. Figure 1 shows the findings for typical and atypical patients. A history scans for two such patients. of systemic complaints (e.g., malaise, fever, sweats, An attempt was made to correlate the duration palpitation, weight loss, tremor, loose bowels) was of the disease before evaluation, as estimated by his

TABLE 5. CORRELATION HISTORY, PHYSICAL FINDINGS, LABORATORY DATA ON TYPICAL AND ATYPICAL SAT PATIENTS

of findings of thyroidWBC Type/ systemic systemic > > > < numberHistory complaintsPhysicalinvolvementenlargementLaboratoryfindingsTypeof9%Dif.Unilat.Nod.None 10,000ESR' 30 mm/hrST4 6.5 @g%RAI Typ/40 34 15 22 14 4 0 9/23 28/28 21/37 40 Atyp/22 9 4 12 1 5 0 3/9 11/14 16/21 22 Total/62 43 19 34 15 9 4 12/32 39/42 37/58 62

* For fractional expressions the numerator indicates the number of abnormal values, the denominator the number of patients tested.

Volume 15, Number 2 83 HAMBURGER

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tory and the observed clinical and laboratory fea There was no clinical evidence of hypenthyroidism. tunes. The subacute nature of the disease and the The thyroid gland was neither enlarged nor tender. retrospective nature of the study complicated this The ST., was 3. 1 ,@g% ( 1 month after the above analysis. Nevertheless, for 24 typical patients the elevated ST4 value) . The RAT was 5 % , and in data seemed adequate for analysis. Since the severity creased only to 9% after TSH. The ESR was 54. and extent of involvement, as well as patient per A diagnosis of subsiding SAT was made. A repeat ceptivity are at least equally important determinants evaluation 2 months later revealed normal ST4, RAT, of the history and physical findings elicited, it is not and ESR values. surprising that Table 6 suggests that duration before Case 2. A 62-year-old woman noted over a 3â€”4 consultation did not seem to have much influence day period the development of a large mass in the upon the findings. left side of the neck. There was neither pain nor For the atypical patients it was much more diffi tenderness, but an intermittent low-grade fever up cult to obtain data on the duration of the disease to 100.5Â°F had been detected. There was also mild since the presenting thyroid features were often un malaise. The RAT was 1% . A diagnosis of thyroid appreciated by the patient until examination was per cancer was suspected but thyroid consultation was formed for some unrelated purpose. sought before surgery. Three instructive atypical patients will be pre There was a 4-cm, firm, nontender mass in the left sented briefly. lobe of the thyroid gland. The ST., was 8.9 ,.@g%, the Case 1. A 37-year-old man complained of sweat ESR 5 1. An RAI after TSH was 8% . The scan (A ing, hand tremor, and a 5-lb weight loss. No thy of Fig. 2 ) revealed all of the tracer within the right roid enlargement or tenderness was noted. The RAT lobe. A diagnosis of SAT was made and treatment was I .5% , and the ST., I 1.2 @g% (NR 4.5â€”8.5 with prednisone, 60 mg daily, was instituted. Within

@Lg% ). A diagnosis of hyperthyroidism was made. 1 week the mass completely disappeared. Prednisone An â€œunknownchemical blockâ€• was invoked to ex was withdrawn over the next 6 weeks. One month plain the low RAT value. Treatment with surgery or later the ST., was 4.5 ,@g%, the ESR I 5, and the antithyroid drugs was advised because â€œobviously RAT 14% . The scan (B of Fig. 2) revealed recov

131! is out of the question in view of the poor uptakeâ€•. ery of function in the left lobe. At this point thyroid consultation was requested. Case 3. A 38-year-old physician was hospitalized

TABLE 6. CORRELATION SYMPTOMS, PHYSICAL FINDINGS, LABORATORY DATA PATIENTSNo. WITH DURATION OF ILLNESS,24 TYPICAL SAT

>patientsDurationofESR Physical findings of >ST4 @g%52weeks4 illnessSystemic symptoms systemic involvement 30 mm/hr6.5

54142â€”4 3 14654weeks3 weeks11 9 53Total 3 2418 15 2413

84 JOURNAL OF NUCLEAR MEDICINE SUBACUTE THYROIDITIS

with an acute episode of atnial fibrillation. The work Table 7 records the principal clinical and labora ing diagnosis was myocardial infarction. In the past tory features of 22 atypical patients. year he had undertaken a vigorous exercise program Some of these patients require special comment. including bicycling and running. He drank 10â€”20 For Patients 1, 2, 9, and 10 the laboratory data are cups of coffee daily. The thyroid gland was minimally minimal. These patients were seen before we were enlarged and very slightly tender. He had been un more alert to the problem of atypical SAT. The spon aware of neck pain. Conversion to sinus rhythm was taneous disappearance of goiter or nodules and re achieved with bed rest, digitalis, and quinidine. Stud turn of thyroid function to normal provided strong ies for myocardial infarction were negative. Thyroid support for a retrospective diagnosis. consultation was requested. The findings for Patient 4, including a small goiter, The ST, was 10.8 @g%, and the ESR 44. The high ESR, normal ST.,, and suppressed RAT which RAT was 1% , unresponsive to TSH. A diagnosis of was not responsive to TSH are compatible with SAT was made. The patient was advised to avoid Hashimoto's disease (which might also have an ele exercises and coffee but otherwise to resume normal vated ESR) . However, recheck 5 months later re activity. vealed further deterioration of thyroid function while During 3 months observation there were no recur the ESR had fallen to normal. This course is more rences of atnial fibrillation but the thyroid doubled consistent with the progression of SAT. We hope to in size. The patient noticed the onset of muscle have further followup indicating complete recovery. cramps, paresthesia, and cold intolerance. The RAT Patient I 8 had neither an ESR determination nor was I 0% , the ST., 0.6 ,@g%, and the serum TSH by followup data, but the high ST4 in conjunction with nadioimmunoassay was 172 @U/ml (greatly ele a suppressed RAT which was unresponsive to TSH vated) . The antithynoglobulin titer was less than make at least a presumptive diagnosis of SAT. 1â€”16 (not elevated) . He was given levothyroxine Treatment for the entire series of patients included 0.2 mg daily for 4 months. Later, after levothyroxine principally reassurance and simple analgesics, usually had been withdrawn for 6 weeks, the thyroid gland aspirin, occasionally supplemented with codeine for was normal in size and thyroid function tests were a few days. None of the patients received adrenal also normal. corticosteroid therapy other than for diagnosis These case reports exemplify the errors which may (three patients presenting with discrete nodules). result from failure to consider the possibility of SAT The value of reassurance deserves emphasis. Most in the absence of neck pain. Therefore, the clinical patients with pain had already tried aspirin-contain features which should suggest atypical SAT and the ing medications, but without relief. However, after procedures useful in confirming a presumptive diag having been assured that their disease was not seni nosis will be summarized. ous, these patients reported that the pain was either Painless, diffuse, or local thyroid enlargement is relieved by simple analgesics or not so severe as to the most common presenting complaint. Clinical fea cause either disability or concern. Analgesics were tunes of hyperthyroidism with an unexplained sub normal RAT value, or the query by a confused phy II IllIlIllIllIllIll II @ I II III II Ill I I I @ sician who cannot explain a high ST4 value in I I I I 11111 I, II I I ,I conjunction with a low RAT, are additional situa II III I.' tions which should suggest the possibility of atypical I II I I.@ I .1 ri I @ I I II RI I I .@ *@tI . HI @ SAT (assuming, of course, that a searching inquiry R I Ill I Iii @â€˜1:@II1' @I I @ I I 1111 1111@IIII1Ifl 1 I L @ for interfering medications was unrewarding). II II I 1

@ Further laboratory support for the diagnosis is I I I 11I11 I jil 11 @ I II IP1 @IIIiIIlI I @ provided by an elevated ESR and a subnormal re I I III I I I. I . I @ sponse to TSH. Scan evidence of patchy and irregu . II1IIIIIIII @.I@@I1111111II 1.I I@... @III.I lan or asymmetrical function following TSH stimula 1 I I 1 L I @ I I I II I I II I I @ tion is additional valuable data. II I I I 11111 II @II I I I An important diagnostic feature is the complete SUPRASTERNAL SUPPASTIRNAL NOTCH NOTCH spontaneous resolution of symptoms, thyroid enlarge A B ment, and abnormal laboratory data within 2â€”4 0 I 2 0 1 2 @ months. I I I _, For suspicious nodules a prompt and complete (centimeters (centimeters) resolution induced by a short course of prednisone, and sustained afterwards, is of considerable diagnos FIG. 2. A. Initial scanafter TSH revealsuptakeof 1@lonly in right lobe, while left lobe mass is functionless. B. Recovery of ticvalue. bilateral function.

Volume 15, Number 2 85 @ @No. &

HAMBURGER

continued until the pain subsided and then discon Four patients had evidence of impairment of func tinued on the patients' initiative. Relapses were not tion more than 1 year after the acute episode. One observed in this series although mild relapses may of these patients was hypothyroid at 3 months and not have been reported. at I 5 months still had an ST., value of 1.2 ,@g% Thirty-four patients were re-evaluated 2â€”3months and an RAT of 1% unresponsive to TSH. The sec or longer after the acute episode. Twenty six had ond patient was normal at 3 months but at 12 completely recovered, although two had transient months the ST, values were 3.0 and 3.5 @g%on two hypothyroidism. One patient considered to have re determinations, and the serum TSH concentration covered had persistent goiter at 3 months. However, by radioimmunoassay on three determinations was it was known that she had goiter before the develop 21 , 36, and 42 @zU/ml(pooled euthyroid serum con ment of SAT. trol I 0.5 @U/ml) . A third patient on birth control Of the eight patients who failed to recover, two medication had free thyroxine indices of 1.2 and 1.0 had goiter and hypothyroidism, respe@tively, ,at 3 (NR 0.8â€”2.1) 13 months after the acute episode. and 5 months after the acute episode. These patients The RAT was 18% and unresponsive to TSH. The may yet experience a complete resolution of the scan revealed a normal appearing left lobe but a very disease. Two additional patients had persistent nod small right lobe remnant measuring only 1 X 1.5 ules, one of which proved to have autonomous func cm. The serum TSH concentration by radioimmuno tion and was probably pre-existing. assay was 21 and 27 @@U/mlon two determinations

TABLE 7. CLINICAL AND LABORATORY FEATURES,22 PATIENTS WITH ATYPICAL SUBACUTETHYROIDITIS

% Age,PresentingThyroid glandESRST,RAI Sexcomplaintsize(mm/hr)(@g%)TSHt Thyroid scan Followup

1 14F Goiter 3OgmT 7.3 Recovery 2 31F Goiter 3OgmT 12.7 Recovery 3 21F Goiter 6OgmT 35 13.0 Goiter & hypo, 16 mo. 4 54F Goiter 40gm 1 37 4.6 2 Hypo at 5 mo. ESR 17. No furtherstudy. 5 38F Goiter 3OgmT 46 6.8 1 Recovery 6 38M Atr. Fib. 3OgmT 44 9.4 1 Transient hypo then recovery 7 36F Unexplained 3OgmT 28 4.7 2 9 Patchy, bilat. function Recovery High$14 8 21F Hair Loss 2OgmT 8.3 1 3 Recovery High514 9 38M Nodule 2.5 cm 3 Recovery 10 17F Nodule 3.0cm 7.0 1 Recovery 11 29F Nodule 1.5 cm 6.1 2 9 Nod. cold, patchy funct. Recovery elsewhere 12 62F Nodule 4.0 cm 9.8 1 5 Rt. lobe funct. only Recovery 13 20F Goiter 30gm 23 6.7 2 10 Patchy, bilat. function Recovery 14 16M Goiter 40 gm 26 7.2 1 4 Recovery 15 23F Goiter 40gm 40 6.4 1 2 None 16 35F Goiter 40gm 48 8.1 1 5 Midline patchy function Recovery 17 23F Goiter 30gm 36 6.1 2 3 None 18 45F Goiter 30gm 8.6 1 1 None 19 37F Goiter 40gm 7.4 1 1 High serum TSH, poor High 514 funct. Rt. lobe, 13 mo. 20 37M Possible 20 gm 54 11.2 2 9 Patchy, bilat. function Recovery Hyper. 21 49M Possible 20gm 45 8.2 2 5 Recovery Hyper. 22 21M Possible 20 gm 32 7.2 1 8 Patchy, bilat. function None Hyper.

S Size is estimated in grams with 20 gm considered normal. â€˜T@',indicates tenderness. For discrete nodules the average diam eter is given. @ t = before, = after.

86 JOURNAL OF NUCLEAR MEDICINE SUBACUTE THYROIDITIS

(pooled euthyroid serum control 10.5 pU/mI). The (5,16). Since most SAT patients do not have an fourth patient returned for the first time 11 years elevated WBC, the study is of little diagnostic value; after a typical episode of SAT. She was euthyroid but however, awareness of this occasional finding is im had a diffuse goiter twice normal size with the right portant, if only to avoid needless search for another lobe larger than the left. explanation. The RAT is usually suppressed. Tf the disease is DISCUSSION localized to a small area, a normal value may be There are numerous synonyms for subacute thy obtained (9,20,22 ) . The suppressed RAT may sim roiditis (SAT). The eponym deQuervain refers to ply reflect cellular injury if the involvement is diffuse the pathologist who described the characteristic his (9,19,24). This is why there is a subnormal response tologic features, features which have given rise to to the relatively small doses of exogenous TSH which names favored in the pathology literature, including readily stimulate normal thyroid tissue ( 1,24) . Pro tubercular, pseudotubercular, giant cell, and gran longed stimulation with larger TSH doses may pro ulomatous thyroiditis. Viral or mumps thyroiditis duce greater RAT increments but still considerably are names reflecting the presumptive etiology. The less than that observed in normals (9) . Even though mumps virus was first to be associated with SAT. SAT has spared a substantial portion of the thyroid More recently a number of other viruses have been the RAT may still be suppressed because the inflam implicated ( I 7) . A designation which relates to the matory process not only impairs cellular function in clinical picture has been preferred by most physi the involved area but also discharges thyroid hor cians. Acute thyroiditis is favored by some but can mone, elevating serum concentrations and thus sup lead to confusion with suppurative thyroiditis which pressing pituitary TSH release ( 19,25 ) . For these is also known as acute. Acute nonsuppurative thy patients exogenous TSH is more likely to produce a roiditis avoids this pitfall but seems needlessly cum significant increment in the RAI, and scanning will bersome. Furthermore, although the more overt show the location of the uninvolved or less involved presentation of SAT may justify the adjective acute, tissue (Figs. 1 and 2). there is growing appreciation that for most patients SAT usually progresses from a more or less acute the designation subacute is appropriate. phase to recovery over a period of 2â€”4 months. There is little difficulty in recognizing SAT in the Occasionally the duration may be prolonged, even classical presentation. A history of neck pain radi to 1 year or more, and punctuated with relapses of ating to the jaw or ear often migrating from one side acute manifestations. A transient period of hypothy to the other is characteristic. Also common are roidism may occur in as many as one in four patients malaise, low-grade fever, sweats, and mild manifesta (2,3) . This may be unappreciated if the patients are tions of hyperthyroidism. This history in conjunction not seen frequently. with a tender somewhat swollen thyroid gland makes This classical picture of SAT may actually be the the diagnosis almost certain. exception rather than the rule (18) . The clinical and It should be noted that the thyroid gland usually laboratory features which the physician observes will is not enlarged beyond one and one half to twice depend upon the rapidity of evolution of the disease, normal size (5,1 1,18) . This enlargement generally the severity and extent of involvement, patient per is diffuse but may be asymmetrical, unilateral, or ceptivity, and the time lapse before the patient seeks even present as a solitary nodule as in our Case 2 medical advice. Since consulting physicians generally (19â€”22). see patients later in the course of the illness, often The most consistent laboratory abnormality is an after prior studies have provided data confusing to elevated ESR, even to 100 mm/hr (2,3,8,1 1 ) . Of the attending physician, the screening process may course, this is not a specific finding and may be seen favor the consultant with an experience consisting with Hashimoto's disease as well (23) . The elevated of a greater proportion of atypical and less acute PBT results from an inflammatory discharge of both SAT patients. For example, Cassidy observed the thyroxine and other iodinated proteins. Hence there absence of tenderness in 12% of his patients, and is a greater elevation in PBI than BET or ST., ( I ,3). only 20% had the characteristic elevation in PBT The greater simplicity and reliability of the ST., de with a depressed RAT (18) . Similarly, for 22 of our termination has led to discontinuation of the PBT in 62 patients pain was not the presenting complaint. many laboratories. However, when the ST., is used Although the RAT was subnormal in all patients, of for diagnosis of SAT, a lesser value will be obtained 58 patients for whom ST., tests were performed, 21 than would have been the case with the PBT. An had values which were not elevated. elevated white blood count (WBC) has been ob Most helpful in the recognition of the atypical served by some (3,6â€”9), and denied by others SAT patient is the unexplained finding of an ele

Volume 15, Number 2 87 HAMBURGER vated ST4 with a suppressed RAT in conjunction with sponse to this treatment, but in contrast to SAT the an elevation in the ESR. The subnormal or asym condition relapses equally promptly when the medi metrical response of the RAT to TSH provides help cation is withdrawn (27) . It is possible that a local ful additional information. The spontaneous resolu ized lymphoma might respond partially to corti tion of the clinical features, including the goiter costeroid treatment; however, these lesions are (nodule) and abnormal laboratory values provides exceedingly rare and would be unlikely to exhibit the confirmation of the presumptive diagnosis of atypical prompt and complete regression characteristic of SAT. SAT (Case 2). Lack of awareness of the changing clinical and The discharge of thyroid hormone which occurs laboratory features of SAT as it progresses through with SAT may adversely affect a marginal cardiovas its course can cause the diagnosis of SAT to be over cular system. Therefore, it seems likely that other looked. This is not serious since SAT is a self-limited SAT patients have had experiences similar to that disorder which almost always results in complete of Case 3. However, the predominance of SAT in recovery. The potential for incorrect diagnosis is of relatively young women may explain the lack of greater concern. Acute pharyngitis is the most com emphasis in the literature upon cardiovascular corn mon diagnostic error (3) . However, the incorrect plications (6) . In Case 3 it would appear that it diagnoses which may lead to serious therapeutic error was the fortuitous combination of mild hyperthyroid include suppurative thyroiditis, hyperthyroidism, and ism, strenuous exercise, and excessive coffee which thyroid neoplasm. produced the unusual presenting manifestation of Suppurative thyroiditis is exceedingly rare, and atnial fibrillation. usually involves a preexisting goiter. The patient is Although adrenal corticosteroids produce prompt very ill. There is high fever, an exquisitely tender relief of the pain and goiter of SAT (2,21 ) , upon fluctuant mass with inflamed overlying skin, and withdrawal of this medication relapse may be a prob enlarged tender adjacent lymph nodes. The WBC is lem (6,28) . Indeed, the frequency of relapse may very high, usually over 20,000. be increased by this treatment (23) . Steroids may In the absence of appreciable pain and tenderness not be suitable for patients with diabetes, peptic hyperthyroidism may be considered early in the ulcer, or a history of tuberculosis. Our experience course of SAT on the basis of evidence of hyper supports the contention that many SAT patients can metabolism and an elevated ST., valve (Case 1). The be treated successfully with simple analgesics and low RAT should suggest SAT. Thyrotoxicosis factitia reassurance (1â€”3,11â€”13) . We, too, were impressed is also possible, but here the RAT responds to TSH, with relapses in our early experience when we used and the scan reveals a normal thyroid gland rather steroids. In our aspirin-treated patients relapse was than the asymmetrical or patchy uptake seen in those not a problem. Patients failing to respond to simple SAT patients who respond to TSH. If a patient with treatment may be given steroids, unless contraindi thyrotoxicosis factitia happens also to have primary cated, or may be considered for x-ray therapy (16). hypothyroidism (the reason for the initial access to The end result of SAT is almost always complete thyroid hormone) , there would be a subnormal re recovery. Persistent goiter may occur (4,6) . Al sponse to TSH. However, the ESR would not be though transient hypothyroidism is rather common elevated. Patients with bona fide hyperthyroidism during recovery (2,3 ) , permanent hypothyroidism is may have suppressed RAI values if they have re rare (3,5,8â€”10,17) . Three of our patients developed ceived iodides (a fact of which neither patient nor this complication. For two the clinical manifestations physician may be aware) . Again the ESR should be were minimal as would have been expected in view helpful. Also, assuming iodide ingestion to cease, of the relatively minor deviations in the laboratory the suppressed RAT will rebound in I or 2 weeks in data. In fact it might be more precise to say that hyperthyroidism. these patients have impairment of thyroid function Unnecessary surgery may be advised for patients rather than frank hypothyroidism. The availability with SAT (Case 2) . In one surgical series approxi of TSH radioimmunoassay was of particular value in mately 10% of patients with thyroiditis had SAT the confirmation of the functional deficiency. A (26) . It has been said that surgery may be unavoid fourth patient, although euthyroid, had impairment able for some SAT patients (8) . Rapidly growing of function as evidenced by a diffuse goiter. Tt seems thyroid cancer may be tender (3) ; hence tenderness possible that patients with mild hypothyroidism or is not diagnostic of a benign process. However, if functional impairment might have been overlooked there is an elevated ESR a trial of adrenal cortico in earlier reports which emphasized complete recov steroids may prove definitive (19,20) . The goiter of ery in all instances. Hashimoto's disease may regress promptly in re Tt has been suggested that the cellular injury pro

88 JOURNAL OF NUCLEAR MEDICINE SUBACUTE THYROIDITIS duced by SAT may predispose to the remote onset 12. TOREKAIT, KUMAOKAS: Subacute thyroiditis treated of hypothyroidism (as has been the case with â€˜31Twith salicylate. N Engi I Med 259: 1265â€”1267,1958 13. MCCONAHEYWM : Treatment of granulomatous (sub treated hyperthyroids) (18). One of our patients acute) thyroiditis. Mod Treat I : 168â€”175,1964 would seem to exemplify this possibility. It seems 14. HAMBURGERJI: Hyperthyroidism: Concept and Con prudent to suggest annual evaluation of thyroid troversy. Springfield, CC Thomas, 1972, pp 5â€”35 function for those who have had SAT. 15. WOOLNERLB. MCCONAHEYWM, BEAHRSOH : Gran ulomatous thyroiditis (deQuervain's thyroiditis). I Clin ACKNOWLEDGMENTS Endocrinol Metab 17: 1202â€”1221, 1957 16. CRILE 0, RAMSEY EW: Subacute thyroiditis. JAMA The initial studies for Case 3 of the case reports were 142: 458â€”462,1950 performed by Michael Podolsky, Dept. of Radiology and 17. VOLPE R: Acute (subacute) nonsuppurative thy Nuclear Medicine, Botsford General Hospital, Farmington, roiditis. In The Thyroid, Werner SC, Ingbar SH, eds, New Mich. 48024, and Zieger Osteopathic Hospital, Detroit, York, Harper & Row, 1971, pp 853â€”861 Michigan. Dr. Podolsky kindly permitted us to see the 18. CASSIDYCE: The diagnosis and treatment of subacute patient in consultation and for followup examinations. thyroiditis. In Clinical Endocrinology ii, Astwood EB, Cas Retrieval of records on subacute thyroiditis patients, re sidy CE, eds, New York, Grune & Stratton, 1968, pp. 220â€” cording of data, and review of the literature was performed 231 by Sheldon Hamburger, student at Oak Park High School, 19. LEWITUS Z, RECHNICJ, LABIN E: Sequential scan Mich., as a summer vacation study project. fling of the thyroid as an aid in the diagnosis of subacute thyroiditis. isr J Med Sci 3 : 847â€”854,1967 REFERENCES 20. DEWIND LT: Reversible manifestations of thyroiditis. 1. VANDERLINDERi, MILNE I: Subacute thyroiditis. JAMA 172: 158â€”159,1960 JAMA 173:1799â€”1802,1960 21. SKILLERNPG : Etiopathogenesis and management of 2. VOLPER: Treatment of thyroiditis. Mod Treat 6: 474â€” thyroiditis. N Y State I Med 63: 241â€”248,1963 496, 1969 22. HAMBURGER JI, KADIAN G, R0sSIN HW: Subacute 3. GREENE iN: Subacute thyroiditis. Am I Med 51: thyroiditisâ€”evolution depicted by serial â€œâ€˜Iscintigram. I 97â€”108,1971 NuclMed6: 560â€”565, 1965 4. BERGEN 55: Acute nonsuppurative thyroiditis. Arch 23. BASTENIEPA, ERMANSAM : Thyroiditis and Thyroid internMed 102:747â€”760,1958 Function, New York, Pergamon, 1972, p 130 5. STEINBERGFU : Subacute granulomatous thyroiditis, a 24. SKILLERN PG. NELSON HE, CRILE G : Some new review. Ann intern Med 52: 1014â€”1025,1960 observations on subacute thyroiditis. I Clin Endocrinol 6. SCHULTZAL: Subacute diffuse thyroiditis. Postgrad Metab 16:1422â€”1432,1956 Med129: 76â€”85,1961 25. CZERNIAKP, STEINBERGAH : The chronology of 7. SWANNNH: Acute thyroiditis. Ann intern Med 56: events in the development of subacute thyroiditis, studied by 68â€”71,1962 radioactive iodine. I Clin Endocrinol Metab 17: 1448â€”1453, 8. MEANS JH, DEGROOT LI, STANBURY JB: The Thy I957 roid and its Diseases. 3rd ed, New York, McGraw-Hill, 1963, 26. HARLANDWA, FRANTZVN : Clinicopathologic study pp 420â€”432 of 261 surgical cases of so-called â€œthyroiditisâ€•.I Clin En 9. ROBBINSJ, RALL JE, TUNNELL JB, et al: The effect docrinolMetab16:1433â€”1437,1956 of thyroid-stimulating hormone in acute thyroiditis. I Clin 27. BLIZZARD RM, HUNG W, CHANDLER RW, et al: EndocrinolMetab11: 1106â€”1115,1951 Hashimoto's thyroiditisâ€”clinical and laboratory response to 10. Iv@ HK: Permanent myxedema: An unusual compli prolonged cortisone therapy. N Engl I Med 267: 1015â€”1020, cation of granulomatous thyroiditis. I Clin Endocrinol I962 Metab 21: 1384â€”1389,1961 28. VAGENAKIS AG, ABREAN CM, BRAVERMAN LE: Pre 11. FURSZYFERJ, MCCONAHEYWM, WAHNERHW, et al: vention of recurrence in acute thyroiditis following corti Subacute (granulomatous) thyroiditis in Olmstead County, costeroid withdrawal. I Clin Endocrinol Metab 3 1: 705â€”708, Minnesota.Mayo ClinProc 45: 396â€”404,1970 1970

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