Common Thyroid Disorders in Children

1. . Common Thyroid Disorders in Children Dr Sarar Mohamed FRCPCH (UK), MRCP (UK), CCST (Ire), CPT (Ire), DCH (Ire), MD Consultant Paediatric Endocrinologist & Metabolic Physician Associate Professor of Pediatrics King Saud University

2. . Agenda • Thyroid Function Test • Congenital Hypothyroidism • Newborn screening for congenital hypothyroidism • Acquired hypothyroidism • Hyperthyroidism • Causes of goiter

4. Thyroid Function: blood tests TSH 0.4 –5.0 mU/L Free T4 (thyroxine) 9.1 – 23.8 pM Free T3 (triiodothyronine) 2.23-5.3 pM

5. Dysfunction Thyroid Gland 1. Too little thyroxin – hypothyroidism a. short stature (aquiered), developmental delay (congenital) 2. Too much thyroxin – hyperthyroidism a. Agitation, irritability, & weight loss

6. Hypothyroidism • Decreased thyroid hormone levels • Low T4 • Possibly Low T3 too. • Raised TSH (unless pituitary problem!)

7. . Causes of hypothyroidism • Congenital • Autoimmune (Hashimoto) • Iodine deficiency • Subacute thyroiditis • Drugs (amiodarone) • Irradiation • Thyroid surgery • Central hypothyroidism (radiotherapy, surgery, tumor)

8. . Clinical features of Acquired hypothyroidism • Weight gain • Goitre • Short sature • Fatigue • Constipation • Dry skin • Cold Intolerance • Hoarseness • Sinus Bradycardia

9. Hypothyroidism with short stature

10. . Diagnosis • High TSH, low T4 • Thyroid antibodies

11. Hashimoto’s Disease • Most common cause of hypothyroidism • Autoimmune lymphocytic thyroiditis • Antithyroid antibodies: • Thyroglobulin Ab • Microsomal Ab • TSH-R Ab (block) • Females > Males • Runs in Families!

12. Subacute (de Quervain’s) Thyroiditis • Preceding viral infection • Infiltration of the gland with granulomas • Painful goitre • Hyperthyroid phase  Hypothyroid phase

13. Treatment of Hypothyroidism • Replacement thyroid hormone medication: Thyroxine

14. Congenital Hypothyroid . • Incidence 1:3000 – 4000 ( more than PKU ) • Female : Male is 2 : 1 • Almost all affected NB have no S/S at birth

15. . Facts Normal Newborn Immature Hypothalamic Pituitary Thyroid Axis Mother supplies T4 to fetus via placenta Mother Fetus T4 Mid-Gestation T4 Mature Hypothalamic Pituitary Thyroid Axis Euthyroid Mother Pregnancy

16. . Congenital Hypothyroidism: Causes • Agenesis or dysgenesis of thyroid gland • Dyshormonogenesis • Ectopic gland • Maternal hypothyroidism

17. . Clinical Features of Congenital Hypothyroidism

18. Newborn Screening

19. Congenital Hypothyroidism . X suspect Clinical Biochemical (screening) Confirm Lab ( TSH & FT4 ) Optional • T scan • B age Rx & FU Thyroxine Growth & D TSH & FT4

20. Newborn Screening • Definitions • Screening: search for a disease in a large unselected population • PKU • Congenital hypothyroidism

21. . Principal of newborn screening • Aim is to identify affected infants before development of clinical signs • Objective : Eradication of MR secondary to CH • The earlier dx the better IQ

22. . Screening Technique • cord blood TSH • blood spot in a filter paper obtained by heel brick for TSH /T4

23. Newborn Screening

24. . Clinical Outcome • Pre-screening data: • Mean IQ = 76 • Post-screening data: • Children screened & treated by age 25 days • Mean IQ = 104

25. Newborn Screening > screening < screening

26. . X Congenital Hypothyroidism

27. Hyperthyroidism • Increased thyroid hormone levels • High T4 +/- High T3 • Low (suppressed) TSH

28. . Causes of hyperthyroidism • Graves Disease • Overtreatment with thyroxine • Thyroid adenoma (rare) • Transient neonatal thyrotoxicosis

29. Graves’ Disease • Most common cause of hyperthyroidism • TSH-R antibody (stimulating) • Goitre, proptosis

30. Hyperthyroidism S&S • Heat intolerance • Hyperactivity, irritability • Weight loss (normal to increased appetite) • diarrhea • Tremor, Palpitations • Diaphoresis (sweating) • Lid retraction & Lid Lag (thyroid stare) • proptosis • menstrual irregularity • Goitre • Tachcardia

31. Neonatal hyperthyroidism born to mother with Graves’ disease A Color Atlas of Endocrinology p51

32. Grave’s ophthalmopathy

33. Hyperthyroid Eye Disease

34. . Investigations • TSH, free T3&T4 • Thyroid antibodies (TSH receptors antibodies) • Radionucleotide thyroid scan (incease uptake)

36. Hyperthyroidism • Treatment • Beta-blockers • Carbimazole • PTU (propylthiouracil) • Radioactive iodine (in adults) • Surgery • 40-70% relapse after 2 years of treatment

37. What is the obvious abnormality of this 14 years old girl? What are the most likely causes? How do you investigate? How do you treat? Quiz

38. . Causes of goiter • Physiological (puberty) • Iodine deficiency • Hashimoto thyroiditis • Graves disease • Tumor • Congenital (maternal antithyroid drugs, maternal hyperthyroidism, dyshormonogenesis)

39. Quiz • 16 year 7 month • Growth failure x 1 1/2 years • Labs:TSH:1008 µIU/ ml (0.3-5.0)T4:<1.0µg/dl (4-12)Antithyro Ab.232U/ml (0-1)A-perox Ab. 592 IU/ml (<0.3)Prolactin:29ng/ml (2-18) patient asked about prognosis what you tell?

40. Newborn Screening