What is the initial workup and treatment for a patient suspected of having Graves' disease?

Initial Workup and Treatment for Graves' Disease

The initial workup for suspected Graves' disease should include TSH as the primary screening test, followed by Free T4 or Free T4 Index (FTI) for accurate diagnosis, with TSH receptor antibody (TRAb) testing recommended when clinical presentation is ambiguous. 1

Diagnostic Workup

Laboratory Testing

• First-line tests:
  • TSH (typically low or suppressed)
  • Free T4 and possibly Free T3 (to assess severity of thyrotoxicosis)
  • TSH receptor antibody (TRAb) testing when clinical presentation is not clear 1, 2

Additional Evaluation

• Physical examination focusing on:

  • Thyroid examination (diffuse goiter, thyroid bruit)
  • Eye examination for signs of ophthalmopathy (exophthalmos, lid retraction)
  • Skin changes (pretibial myxedema)
  • Cardiovascular examination (tachycardia, atrial fibrillation)

• Imaging:

  • Thyroid ultrasound may be contributive but is not recommended as first-line 2
  • Thyroid scintigraphy reserved for cases with negative antibodies or when another etiology is suspected 2
  • Orbital imaging (CT or MRI) if ophthalmopathy is present to evaluate extraocular muscle involvement 3

Treatment Options

1. Antithyroid Medications

• First-line pharmacological treatment:

  • Methimazole is the preferred antithyroid medication 1, 4
  • Starting dose: 10-40 mg daily based on severity
  • Treatment duration: 12-18 months
  • Goal: Maintain FT4 or FTI in high-normal range using lowest possible dose 1

• Monitoring:

  • Every 2-3 weeks initially, then every 4-6 weeks until euthyroid
  • Watch for side effects: agranulocytosis, hepatitis, thrombocytopenia
  • Instruct patients to report immediately any symptoms of side effects (sore throat, fever, rash, liver dysfunction) 1

• Special considerations:

  • Propylthiouracil reserved for first trimester of pregnancy, methimazole intolerance, or severe liver injury 1

2. Symptom Management

• Beta-blockers (propranolol or atenolol) for symptomatic relief of:
  • Tachycardia
  • Tremor
  • Anxiety
  • Heat intolerance
  • Continue until thyroid hormone levels normalize 1

3. Definitive Therapy Options (after initial control)

• Radioactive Iodine (RAI):

  • Contraindicated in pregnancy and active/severe orbitopathy
  • Steroid prophylaxis warranted in patients with mild/active orbitopathy
  • Women should not breastfeed for four months after treatment 1

• Thyroidectomy:

  • Should be performed by experienced high-volume thyroid surgeon
  • Preparation with methimazole and potassium iodide solution
  • Consider for patients with severe hyperthyroidism or large goiters
  • Risks include hypoparathyroidism and laryngeal nerve damage 1

Management Algorithm Based on Severity

Grade 1 (Mild Symptoms)

• Continue antithyroid medication
• Beta-blockers for symptomatic relief
• Close monitoring of thyroid function 3, 1

Grade 2 (Moderate Symptoms)

• Consider endocrine consultation
• Beta-blockers for symptomatic relief
• Hydration and supportive care
• For persistent thyrotoxicosis (>6 weeks), consider additional workup 3

Grade 3-4 (Severe Symptoms)

• Endocrine consultation required
• Consider hospitalization
• Higher doses of antithyroid medications
• Beta-blockers
• Additional therapies including steroids, potassium iodide solution (SSKI), or surgery 3, 1

Special Considerations

Pregnancy

• Goal: Maintain FT4 in high-normal range using lowest possible dose
• Close monitoring as thyroid dysfunction may diminish as pregnancy proceeds
• Propylthiouracil preferred in first trimester, methimazole in second and third trimesters 1

Graves' Ophthalmopathy

• Physical examination findings of ophthalmopathy warrant early endocrine referral
• May require specialized treatment independent of hyperthyroidism management
• Ocular lubricants for exposure related to eyelid retraction and proptosis 3, 1

Common Pitfalls to Avoid

• Failure to monitor for antithyroid medication side effects
• Inadequate follow-up and overlooking drug interactions
• Inappropriate use of RAI in pregnancy or patients with active orbitopathy
• Treating hyperthyroidism without addressing associated ophthalmopathy 1