Five Patients with Painless Thyroiditis Simultaneously Developed in a Nursery School.

Abstract

Painless (silent) thyroiditis (PT) occurred simultaneously in 1 male and 4 females aged 21 to 52 years working at a nursery school. Clinical symptoms did not include goiter, or pain or tenderness of the neck in any of the patients but were characterized by edema of the lower legs as well as palpitation and loss of body weight as observed in subacute thyroiditis. General blood analysis showed that all patients were negative for C-reactive protein (CRP) and 3 had mild impairment of liver function. Examination of thyroid function suggested transient thyrotoxicosis accompanied by a marked reduction in radioactive iodine uptake (RAIU), but antithyroglobulin hemagglutination antibody (TGHA) and antithyroid microsomal hemagglutination antibody (MCHA) were negative in all patients. Examination of various viral antibodies showed no significant changes in their titers. Thyrotoxicosis was transient and disappeared without treatment or by glucocorticoid administration. Our results suggested that PT observed in this study was caused by some environmental factor. The possibility of an unidentified virus as a factor cannot be ruled out.

Familial Occurrence of Silent Thyroiditis

“…Only 27% (12 patients) of the patients were negative for these antibodies. Thus, the absence of antithyroid antibodies may be characteristic of such silent thyroiditis as shown in the present and previous studies [11,12].…”

“…In addition, these antibodies measured by the particle agglutination method were not detected in the five patients in the study by Ogura et al [11] and 12 patients in the study by de Bruin et al [12]. Silent thyroiditis is considered a variant form of chronic thyroiditis and many patients with silent thyroiditis have anti-Tg and anti-TPO antibodies in their serum [18,19].…”

“…Low CRP concentrations and ultrasonograms indicated that silent thyroiditis had developed in the three members. In 1988, Ogura et al [11] reported that silent thyroiditis occurred simultaneously (October) in five staff members of a nursery school. In 1990, de Bruin et al [12] reported the presence of atypical subacute thyroiditis, which developed in 12 patients, including two family members in the same period (July-September).…”

“…In addition, silent thyroiditis can also develop in patients after the cessation of steroid treatment for rheumatoid arthritis [4], after adrenalectomy in patients with Cushing's syndrome [5,6], after the administration of gonadotropin-releasing hormone analogues [7], and after viral infections [8][9][10]. However, the outbreak of silent thyroiditis (or atypical thyroiditis) has been indicated in few reports [11,12] Here, we report the cases of two brothers and their mother who developed silent thyroiditis in spring. They had allergic rhinitis caused by Japanese cedar pollen.…”

Painless Thyroiditis Associated with Severe Inflammatory Reactions in Amyloid Goiter: A Case Report.

“…Furthermore, previous reports describing painless subacute thyroiditis [23,24], including two `outbreaks' of cases [30,31], do not fully explain the etiology for the condition, except for a report by de Bruin et al [31] in which the patient exhibited significantly lower frequency of HLA-B35 but increased frequency of HLA-B15 with painless subacute thyroiditis compared with the painful forms. From a diagnostic standpoint, painless thyroidal destruction with definite inflammatory reactions is very difficult to distinguish from etiologies of other fevers of unknown origin such as infections, malignancy and collagen disease, which makes thorough systemic examinations necessary [12,23,24].…”