|
Introduction
  • Most common cause of hyperthyroidism
  • An autoimmune disease with stimulating anti-TSH receptor antibodies
    • a type II hypersensitivity
    • anti-microsomal, anti-thyroglobulin antibodies also present
  • Female dominant
    • HLA-B8, Dr3 association
  • Often incited during stress
    • e.g. childbirth, infection, steroid withdrawal
Presentation
  • Symptoms
    • heat intolerance
    • weight loss
    • hyperactive
    • diarrhea
    • hyperreflexia
    • tachycardia, palpitations, arrhythmias
      • thyroid hormone increases heart rate and contractility and decreases SVR 
    • warm moist skin and sweating
    • hypertension
  • Physical exam
    • symmetrical, non-tender thyroid enlargement 
    • ophthalmopathy (proptosis, exophthalmos)
      • due to glycosaminoglycan deposition
    • pretibial myxedema 
    • digital swelling
Evaluation
  • Serology 
    • ↑ total serum T4
    • ↑ free T4
    • ↓ serum TSH
    • diffusely ↑ 123I uptake 
Treatment
  • Medical
    • β-blockers
    • thionamides 
      • result in reduced hormone synthesis
      • PTU and methimazole
        • discontinue if agranulocytosis occurs as these are side effects of these medications
    • during pregnancy, first-line is propranolol, followed by propylthiouracil
      • if these treatments do not work and symptoms are severe, thyroidectomy is the treatment of choice
        • complications include
          • recurrent laryngeal nerve injury
          • hypocalcemia
            • due to PTH gland removal resulting in the classic findings of hypocalcemia (tetany, QT prolongation, etc.)
    • 131I ablation   
      • hypothyroidism may result 
      • contraindicated in pregnancy 
      • may cause transient worsening of exophtalmos or hyperthyroid symptoms due to release of thyroid hormone with thyroid cell destruction 
        • prevention: pretreatment with glucocorticoids 
Prognosis, Prevention, and Complications
  • Stress-induced catecholamine surge
    • may be fatal by arrhythmia
  • Pregnancy complications
    • anti-TSH receptor antibodies may cross placenta and produce hyperthyroidism in the fetus
 

Please rate topic.

Average 5.0 of 3 Ratings

Questions (16)
EVIDENCE & REFERENCES (14)
Topic COMMENTS (13)
Private Note