Resumen

MARSIGLIA G, Italo. Estudio clínico y epidemiológico de la tiroiditis subaguda (tiroiditis granulomatosa de de Quervain). Gac Méd Caracas [online]. 2006, vol.114, n.4, pp.273-290. ISSN 0367-4762.

In this prospective clinical-epidemiologic study about subacute thyroiditis made in Caracas, Venezuela, during 44 years (1961-2004), in a sample of 11 648 cases of a private internal medicine consultation, there were found 30 cases of subacute thyroiditis. Prevalence of 0.26 %, incidence of 0.68 cases per year, and subacute thyroiditis relative frequency equivalent to 2.9 % of all thyroid disease cases, were conclusive that subacute thyroiditis is a non common disease in our environment. Female accounted for 60 % of cases. Mean age was 44.80±11.89 years, ranging between 21 to 78 years, modal class 5th decade. The acute onset occurred in 2/3 of the cases, with fever, fatigue and nervousness as frequent manifestations. Neck pain or pain referred to the pharynx occurred in 87 % of cases. Thyroid gland enlargement, mild to moderate and bilaterally, tender and firm at palpation, showed nodular pattern in 93 % of cases. Migratory pattern and early recurrences were observed isolated or jointly in half of the cases. In our experience, the presence of "migratory nodules" must be considered an important key for diagnosis of subacute thyroiditis. Atypical forms, painless or unilateral subacute thyroiditis affected 27 % of cases. Systemic character of subacute thyroiditis was suggested by transitory findings of hepatomegaly, lymphadenopathy and hematological, hepatic and proteins tests alterations. Between 1st and 6th weeks of subacute thyroiditis, transitory thyrotoxicosis occurred in 78 % of cases; serum TSH was the most sensible hormonal index with low concentrations in 86 % cases. Actually, T3 and T4 increases, TSH and thyroid I-131 uptake suppression and clinical manifestations of thyrotoxicosis, maximized intensity and frequency at 3 weeks of disease onset. Thyroid I-131 uptake was depressed in 83 % of cases, especially in association with thyrotoxicosis and thyroid bilateral disease. Multiple and simple linear regression analysis showed inverse relationship between unilateral or bilateral extension of subacute thyroiditis and thyroid I-131 uptake, time of evolution of subacute thyroiditis and serum T3T and, in the acute phase of subacute thyroiditis, thyroid I-131 uptake and serum T3T. Statistical findings and physiopathology of subacute thyroiditis could have the following explanation: 1. Suppression of thyroid I-131 uptake depends as much of thyroid tissue damage (higher suppression of I-131 uptake at higher extension of inflammatory process), as of serum T3T concentration (higher suppression of thyroid I-131 uptake at higher serum T3T concentration, that produces TSH inhibition); and 2. T3T increase occurs in the acute phase of subacute thyroiditis (inverse relationship between time of evolution of subacute thyroiditis and serum T3T). Additional findings in the acute phase of subacute thyroiditis were: scintigraphy do not showed thyroidal image in 73 % of cases; thyroid ultrasonography revealed moderate increase of thyroid volume and diffuse or focal hypoechogenicity; and anti-TPO antibodies were negative in 91 % of cases. In the intermediate phase of subacute thyroiditis frequency of hypothyroidism was 30 %. Transitory hypothyroidism (27 %), clinical or subclinical, showed "biphasic thyroiditis" pattern, occurring after transitory thyrotoxicosis, 1 1/2 to 6 1/2 months after onset of disease, with duration between 1/2 to 6 months and mean 2±1.73 months. Response to prednisone treatment was excellent and after one week, remission of thyrotoxicosis was observed. Complete recovery occurred in 97 % of cases. Only one case had permanent hypothyroidism. Late recurrence was present in one patient, 16 years after a first episode of subacute thyroiditis. In this study, subacute thyroiditis had a mean duration of 3.36±2 months, ranging 1 to 15 months. The follow up mean per case was 4.8 years.

Palabras clave : Subacute thyroiditis; de Quervain thyroiditis..