Clinical manifestations and outcome of polyarthralgia associated with chronic lymphocytic thyroiditis

Arthralgia is among the most frequent musculoskeletal symptoms occurring in patients with chronic lymphocytic thyroiditis (CLT), often causing pain and physical impairment over extended periods of time. Our study aims to characterize arthralgia and, in particular, polyarthralgia (PA) associated with CLT and to evaluate the influence of thyroid replacement therapy.

Of 130 patients affected with CLT attending the Division of Rheumatology for rheumatic complaints, the authors sequentially selected 20 patients with PA without any known rheumatic diseases. Of these 20 patients, 8 were euthyroid, 2 hyperthyroid, and 10 hypothyroid. The last group had never undergone therapy for thyroid disease; then, they were treated with thyroxine and followed up for 24 months. Clinical assessment included the number of joints affected by pain (NAJ), the visual analogic scale of pain (VAS), the duration of PA (number of days), and the intake of acetaminophen.

At baseline, the only correlations in the 20 patients with PA were between NAJ and antithyroid microsomal antibodies (r =.782; P <.001), thyroid stimulation hormone (r =.651; P =.001), and erythrocyte sedimentation rate (r =.511; P = 0.021), respectively. During follow-up, although symptoms improved in the 10 hypothyroid patients treated with thyroxine, a statistical significance was reached only after 12 months.

Patients with CLT may be affected with PA severely, even in absence of hypothyroidism. Replacement therapy with thyroxine in hypothyroid patients with CLT induced a progressive but gradual improvement of symptoms.