Skip to Main Content

++

Graves disease is a multisystem autoimmune disease involving hyperthyroidism, eye manifestations, and dermopathy.1-12In children, in contrast to adults, the latter manifestation are absent or mild.

++

Epidemiology

++

The disease occurs in preschool children; rarely, it may begin in infancy. However, the incidence increases sharply as children approach adolescence. Girls are affected six to eight times more often than boys. Graves disease, like Hashimoto thyroiditis, has a genetic basis; a high proportion of patients have a family history positive for goiter, hyperthyroidism, or hypothyroidism. It is believed that both Graves disease and Hashimoto thyroiditis arise randomly in a genetically predisposed population. The concordance rate for Graves disease in monozygotic twins has been reported as 30% to 60%; in dizygotic twins, it is only 3% to 9%. Family studies have disclosed a high percentage of circulating antithyroid antibodies in near relatives. Furthermore, certain HLA haplotypes, such as HLA B8 and Dr3 in Caucasians, and linkage to genetic determinants on the X chromosome and chromosomes 14 and 20 have been reported in affected families.

++

Pathophysiology

++

The hyperthyroidism is due to the production of thyroid-stimulating autoantibody, which, like thyroid-stimulating hormone (TSH), stimulates the TSH receptor. The three principal autoantigens in Graves disease (the TSH receptor, thyroid peroxidase, and thyroglobulin) have been cloned. The TSH receptor autoantibodies have the major pathogenetic role in Graves disease. The production of thyroid stimulating antibodies by B lymphocytes is probably a secondary response to a cell-mediated immune reaction requiring involvement of T lymphocytes in a manner similar to that postulated for Hashimoto thyroiditis. Cell cultures of lymphocytes from patients with Graves disease produce immunoglobulins only after stimulation with phytohemagglutinin. Because the latter substance stimulates only T cells (which are incapable of secreting immunoglobulins), it may be inferred that both cell-mediated and humoral immune mechanisms are involved in the genesis of the thyrotoxic state. This is supported by more recent studies indicating that thyrocytes can be activated by TSA + insulinlike growth factor 1 (IGF-1) to express powerful T-cell chemoattractants that stimulate T-cell infiltration independently of the TSH receptor.

++

Clinical Features

++

The onset of thyrotoxicosis is usually insidious, with a period of increasing nervousness, palpitation, increased appetite, and muscle weakness.8-11 Marked weight loss occurs in some patients, usually in association with a voracious appetite. Occasionally, children and especially adolescents show a weight increase with the onset of the disease. Except for exophthalmos and other eye signs, the symptoms of thyrotoxicosis are nonspecific and, for prolonged periods, may be mistaken for some other condition. Behavioral abnormalities, declining school performance, and emotional instability frequently dominate the clinical picture. In other patients, cardiovascular signs are most prominent, and attention is focused on a cardiac murmur or decreased exercise tolerance. Fatigability and objective muscle weakness are observed in 60% to 70% of patients. The pulse pressure widens, and the precordium may be overactive. Other signs of sympathetic overactivity ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.