Introduction

• The common causes of hyperthyroidism in children and adolescents would be Graves’ disease and the acute phase of Hashimoto’s thyroiditis
• A low thyroid stimulating hormone (TSH) that is low but above 0.2U/L with a normal free T4 level does not necessarily indicate hyperthyroidism. Many children will have a low TSH with normal free T4 after being unwell 
          - Would recommend repeating thyroid function test in 6 weeks in these cases, prior to referral

Initial work up

• TSH, fT4, fT3
• TSH receptor antibodies (specific to Graves’ disease), anti-TPO and anti-thyroglobulin antibodies – antibody tests can be requested at time of next TFTs if not done initially

When to refer

Refer + phone call:

• Low TSH and elevated fT4/fT3 
  • If clinically symptomatic (eg palpitations, significant weight loss) or TSH is below lower limit of detection of lab and fT4 is significantly elevated (>30pmol/l), please call the endocrinologist / fellow on call as urgent review ± instigation of therapy may be required.

Routine referral:

• If initial tests only mildly deranged and clinically well (eg TSH low but above 0.2U/l or fT4 is mildly elevated but <30pmol/l) suggest refer to OPD and also arrange repeat test in ~2-3 weeks (with autoantibodies as above if not done previously).

Referral information needed

• Clinical history / reason for testing
• Copies of reports of abnormal thyroid function tests and antibody testing as above
• Height and weight (and date of assessment)
• Relevant family / personal history of thyroid disease or other autoimmunity

Contact information

• For clinical advice, the endocrinology fellow or endocrinologist on call can be contacted through the hospital switch board (03) 9345 5522
• Outpatient booking enquiry information (03) 9345 6180

Author

• Guideline developed by RCH Endocrinology Department