Hyperthyroidism

Hyperthyroidism, also known as Graves disease, is most common in girls age 10-15 with an autoimmune disorder familial history. Graves disease most commonly presents with a goiter, as well as warm moist skin, restlessness, proximal muscle weakness, fine hand tremor with arm extension, growth acceleration and bone age, and potentially delayed puberty. Approximately one-third of children with hyperthyroidism develop Graves ophthalmology, yet most cases present as mild.

Diagnosis for pediatric hyperthyroidism typically begins with the screening of T3 and T4 levels, thyroid or thyrotropin receptor antibodies, and thyrotropin. T3 and T4 levels will be elevated in Graves disease, but physicians should note the level elevation may not positively correlate with symptom severity. Treatment of Graves disease typically begins with anti-thyroid drug therapy, such as methimazole. Propylthiouracil is not recommended because of liver toxicity. In severe cases, a cardioselective beta-blocker can be used temporarily. Because only an estimated 35% of children and adolescents achieve remission on drug-only treatment, definitive therapy can be considered in the form of a thyroidectomy or radioiodine ablation.

Smoking behavior in a randomized study of the effect of radioiodine therapy on ophthalmopathy and in a case series of patients with Graves ophthalmopathy receiving orbital radiation therapy and glucocorticoids.

Design: Randomized, single-blind study of smoking and mild ophthalmopathy after radioiodine therapy (study 1) and a retrospective cohort study of the association between smoking and response of severe ophthalmopathy to treatment (study 2).

Setting: University medical center.

Patients: 300 patients with mild ophthalmopathy (study 1) and 150 patients with severe ophthalmopathy (study 2).

Intervention: In study 1, patients received radioiodine alone or radioiodine and a 3-month course of oral prednisone (initial dosage, 0.4 to 0.5 mg/kg of body weight per day). In study 2, patients received high-dose oral prednisone for 6 months (initial dosage, 80 to 100 mg/d) and underwent orbital radiation therapy by linear accelerator (cumulative dose, 20 Gy per eye over 2 weeks).

Measurements: Degree of ophthalmopathy was assessed by overall evaluation (inflammatory changes, proptosis, extraocular muscle dysfunction, corneal involvement, and optic neuropathy).

Results: In study 1, ophthalmopathy progressed in 4 of 68 nonsmokers (5.9% [95% CI, 3% to 9%]) and 19 of 82 smokers (23.2% [CI, 13% to 33%]) who received radioiodine alone (P = 0.007). Ophthalmopathy was alleviated in 37 of 58 nonsmokers (63.8% [CI, 51% to 78%]) and 13 of 87 smokers (14.9% [CI, 10% to 26%]) who received radioiodine plus prednisone (P < 0.001). In study 2, 61 of 65 nonsmokers (93.8% [CI, 90% to 98%]) and 58 of 85 smokers (68.2% [CI, 57% to 78%]) responded to treatment (P < 0.001).

Conclusions: Cigarette smoking increases the risk for progression of ophthalmopathy after radioiodine therapy and decreases the efficacy of orbital radiation therapy and glucocorticoid therapy.