ABSTRACT
A type of subacute thyroiditis occurring epidemically in a factory in Helsinki was observed in 44 cases. In every case the thyroiditis followed an acute infection of the upper respiratory tract. The variation in incidence during one and a half years was in good agreement with that of the acute infection. Since Helsinki is in an endemic goitre region, the fact that the disease was of the migrating type was of great diagnostic importance. In all cases but one, the nodules have persisted. One case of asymptomatic thyroiditis was seen. In the majority of the patients the thyroid gland had been carefully palpated before the thyroiditis occurred, and in all cases the condition was followed up by the same investigator. Special attention was paid to changes in the iodine metabolism, the serum cholesterol, the electrophoretic distribution pattern of the serum proteins, and the circulating thyroid auto-antibodies. In many cases needle biopsy of the thyroid gland was performed. Thyroid function invariably returned to normal with time, although one patient remained in a hypothyroid state for about a year. In no cases were thyroid auto-antibodies found. For the beta-globulin fraction, the electrophoretic distribution pattern of the serum proteins gave values which were still not normalized in any case, and only in two cases was the alpha2-fraction normalized. The needle biopsy, when thyroid tissue was obtained, showed almost the same picture as in endemic goitre, but in some specimens nonspecific inflammatory changes were seen. Prednisolone relieved the symptoms, but did not affect the course of the disease. According to the present observation this type of epidemic thyroiditis would seem to represent a form of nonspecific subacute thyroiditis.
COVID-19 mRNA vaccine may trigger subacute thyroiditis