Treatment of Thyroid Issues in Children
The treatment of thyroid disorders in children should be tailored to the specific condition, with hypothyroidism treated with levothyroxine replacement therapy and hyperthyroidism managed initially with antithyroid medications such as methimazole.
Diagnosis and Evaluation
Initial Assessment
- Measure TSH as the primary screening test for thyroid dysfunction 1
- For suspected thyroid disease, evaluate both TSH and free T4 levels 2, 1
- Assess for clinical signs specific to:
Risk Groups Requiring Screening
- Children with type 1 diabetes (17-30% develop thyroid autoimmunity) 2
- Children with Down syndrome 2
- Children with PTEN hamartoma tumor syndrome (starting at age 7) 2
- Children with DICER1 syndrome (starting at age 8) 2
- Children with chronic kidney disease before starting growth hormone therapy 2
Treatment of Hypothyroidism
Congenital Hypothyroidism
- Begin levothyroxine at 10-15 mcg/kg daily as soon as possible after diagnosis, preferably within the first 2 weeks of life 3
- Target TSH <5 mIU/L and free T4 in the upper half of age-specific reference range 5
- Monitor TSH and free T4 at 2 and 4 weeks after treatment initiation, 2 weeks after any dosage change, then every 3-12 months 6
Acquired Hypothyroidism
- Levothyroxine dosing based on weight and age 6
- For children with subclinical hypothyroidism (elevated TSH with normal T4), treatment decisions should consider:
- Presence of symptoms
- TSH level (higher levels more likely to need treatment)
- Presence of thyroid antibodies (indicating autoimmune thyroiditis) 1
Special Considerations
- Pregnancy may increase levothyroxine requirements; monitor TSH each trimester 6
- Return to pre-pregnancy dose immediately after delivery 6
- In children with chronic kidney disease, correct metabolic acidosis (serum bicarbonate ≥22 mEq/l) before initiating growth hormone therapy 2
Treatment of Hyperthyroidism
Graves' Disease (most common cause - >95% of pediatric hyperthyroidism)
- First-line treatment: Antithyroid medications, with methimazole as the initial drug of choice 4, 7
- Avoid propylthiouracil due to risk of hepatotoxicity 7
- Long-term options (due to low remission rates with medications alone):
- Radioactive iodine therapy (generally for children with poor medication compliance, those not in remission after 1-2 years of medication, or those with major adverse effects) 8
- Surgery (total or near-total thyroidectomy) for children <5 years who don't respond to medications, those with very large goiter, or severe ophthalmopathy 8
Monitoring and Follow-up
- Regular monitoring of thyroid function
- Surveillance for medication side effects
- Evaluation for signs of remission or recurrence
- Lifelong follow-up with levothyroxine in cases of ablative treatments 4
Thyroid Storm Management
- Recognize this rare life-threatening emergency in children with hyperthyroidism showing systemic decompensation 7
- Requires immediate intensive care management
Neonatal Hyperthyroidism
- Can occur in infants born to mothers with Graves' disease due to transplacental passage of TSH receptor stimulating antibodies 7
- Requires prompt recognition and treatment to prevent complications
Common Pitfalls to Avoid
- Don't rely solely on newborn screening for detecting all cases of congenital hypothyroidism 3
- Don't use propylthiouracil as first-line therapy for pediatric hyperthyroidism due to hepatotoxicity risk 7
- Don't order complete "thyroid panels" for screening; start with TSH alone to avoid detecting minor, clinically insignificant abnormalities 1
- Don't ignore clinical symptoms of hypothyroidism even if screening tests are normal 3
Remember that untreated thyroid disorders in children can lead to significant impacts on growth, development, and cognitive function, making prompt diagnosis and appropriate treatment essential.