Thyroid Gland Diseases in Children

1. Thyroid Gland Diseases in Children Riga Olena KhNMU

4. Excretion of iodine ( in urine) • 100-200 μg/l – normal level • 201-299μg/l – increase level • > 300μg/l - increase of intake in food • Deficiency: • < 20 μg/l – severe • 20-49μg/l - moderate • 50-99μg/l - mild

5. The steps of thyroid hormone synthesis • Monoiodotyrosin (MIT) • Diiodotyrosin (DIT) • 1 molecula MIT + 2 DIT → thyroxin T4 • 1 molecula MIT + 1 DIT → triiodothyroxinT3 Under thyroperoxidase control

7. Peripheral conversation T3 from T4 • Both T4 and T3 circulate in plasma bound to the plasma thyroid hormone-binding protein (TBP) Thyroxine-binding globulin. • Thyroid produces only 8 μg of T4 and 4 μg T3 daily. • Serum T3 concentration is usually low because of reduced conversation from T4.

8. The factors that destroyed of conversation T4→T3 • systemic disease • starvation, anorexia • surgical intervention • newborn period • gerontological period • glucocorticosteroids • β-adrenoblocks • amiodarone (cordaron) • propylthyouracil

9. Action of thyroid hormones • Genomic effects: the interaction of TH and its receptors is believed to precede other cellular events of messenger RNA and specific protein synthesis

10. Action of thyroid hormones • Maturation of the CNS: lack of TH in the first year or two results in decreased brain cell size and number. Myelinization of axons is retarded leading to abnormalities and dendritic arborization

11. Action of thyroid hormones • Maturation of the skeletal and dental system • Maintenance of oxidative metabolism and heart production • Control of temperature production • TH differentiates all tissues and organs

12. Diagnostic of Thyroid gland disease • Visual & palpating method • Investigation of thyroid function (basal level of freeT3 ,freeT4) • Functional tests (TSH) • USG, radiography, scanning, etc. • Biopsia

13. Diagnostic of Thyroid gland disease • Serological tests: *Markers of autoimmune disease (antibodies to thyroglobulin, thyroperoxidase, to TSH-receptors) *Markers of cancer (thyroglobulin, calcitonin)

14. Goiter WHO (1994) • 0 – goiter is absent • I – goiter isn’t visualized, but it’s size less than distal phalanx of thumb • II – goiter is palpated & visualized

15. Functional condition of Thyroid influence may be as • Euthyroidism • Hypothyroidism • hyperthyroidism

16. Нypothyroidism • Hypothyroidism-syndrome with particular or total deficiency T3 and T4 or theirs acts to target cells

17. Classification of hypothyroidism Disturbances • PRIMARY - defects of biosynthesis of T3, T4 due to pathology of thyroid gland • SECONDARY - decreasing T3, T4 due to deficiency of TSH (pituitary) or TRH (hypothalamus) or Resistance of receptors for T3, T4

18. Classification of hypothyroidism Onset Congenital Acquired (rare)

19. Classification of hypothyroidism Clinic & biologic data • Latent (subclinical) T3 -N, T4 –N, TSH > 10 mU/l • Manifestation of disease due to ↓ T4 (at first) & ↓ T3 • Complicate

20. ETIOLOGY OF CONGENITAL HYPOTHYROIDISM • Primary hypothyroidism Thyroid dysgenesis (aplasia, hypoplasia, or ectopic gland) • Inborn error of thyroid hormone synthesis, secretion, or utilization • Maternal goitrogen ingestion or radioactive iodine treatment • Iodine deficiency (endemic goiter) • Autoimmune thyroiditis

21. ETIOLOGY OF CONGENITAL HYPOTHYROIDISM (c’d) • Hypothalamic or pituitary hypothyroidism • Pituitary aplasia • Septo-optic dysplasia • PIT1 mutation (deficiency TSH, GH, Prol • PROP-1 mutation (deficiency TSH, GH, Prol,Lh,FSH,ACTH) • Thyrotropin unresponsiveness

22. SYMPTOMS OF CONGENITAL HYPOTHYROIDISM • There is a tendency towards prolonged gestation with 1/3 of pregnancies lasting 42 weeks or more • Prolonged jaundice • Lethargy • Constipation • Feeding problems • Cold to touch

23. SIGNS OF CONGENITAL HYPOTHYROIDISM Skin mottling and Dry skin Umbilical hernia and Distended abdomen Jaundice Macroglossia Large fontanels Wide sutures Hoarse cry Muscle Hypotonia Slow reflexes

24. Minority of CH • Puffy myxedematous face • Depressed nasal bridge with hypertelorism • Large protruding tongue with an open mouth • Cold, motted skin • Short neck • Palpebral fissures are narrow • Short fingers • Fat deposits between neck and shoulders • Hiar is coarse, brittle and scanty • Hiarline reaches far down on the forehead

26. DIAGNOSTIC STUDIES IN HYPOTHYROIDISM Thyroid scan – 99mTc or 123 IT3 resin uptake Bone age TSH !!! Free T4 – if hypothalamic- pituitary hypothyroidism suspected TBG – if TBG deficiency suspected Anti-thyroid antibodies – if history of maternal thyroiditis

27. Biochemical hallmarks of CH • Low serum T4 and T3 with evaluated TSH (primary) • T3 –normal, T4 ↓- severe or longstanding • T4 –normal but TSH is elevated – compensative CH, transient or subclinical • T4↓ but TSH normal- congenital TBG-deficiency or hypothalamic-pituitary hypothyrodism

28. Biochemical hallmarks of CH Other: • Elevated serum cholesterol • Elevated creatinphosphokinase • Hyponatriemia

29. Instrumental data • Slightly decrease heart rate and amplitude of R wave (ECG) • Increase projection period, left ventricular wall diameter, decrease LV chamber size and decrease cardiac output (EchoCG) • Low-amplitude diffuse slowing (EEG)

30. Treatment L-thyroxin • Preterm 8 – 10 μg/kg • 0-3 mo 10 – 15 μg/kg • 3-6mo 8 – 10 μg/kg • 6-12mo 6 – 8μg/kg • 1-3years 4 – 6 μg/kg • 3-10years 3 – 4 μg/kg • 10-15years 2 – 4μg/kg • > 15years 2 – 3 μg/kg

31. ETIOLOGY OF ACQUIRED HYPOTHYROIDISM • Chronic lymphocytic (Hashimoto`s) thyroiditis (CLT) • Subacute thyroiditis (De Quervain`s) • Goitrogens (iodide, thiouracil, etc.) • Thyroidectomy or ablation following radioactive iodine • Infiltrative disease (e.g., cystinosis, histiocytosis X)-systemic disease

32. ETIOLOGY OF ACQUIRED HYPOTHYROIDISM (c’d) • Hypothalamic or pituitary disease • Congenital thyroid disorders, e.g., ectopia, may not decompensate until later childhood and thus may appear acquired • Peripheral resistance to thyroid hormones, including receptor defects • Jatrogenic (propylthiouracil, methimazole, iodides, lithium,amiodarone) • Hemangiomas of the liver

33. SYMPTOMS OF ACQUIRED HYPOTHYROIDISM • Slow growth • Puffiness • Decreased appetite • Constipation • Swollen thyroid gland • Lethargy • Drop in school performance • Cold intolerance • Galactorrhea • Menometrorrhagia

34. SIGNS OF ACQUIRED HYPOTHYROIDISM • Short stature • Decreased growth velocity • Increased upper to lower segment ratio • Delayed dentition • Myxedema or mildly overweight • Goiter

35. SIGNS OF ACQUIRED HYPOTHYROIDISM (c’d) • Delayed reflex return • Dull, placid expression • Pale, thick, carotenemic, or cool skin • Muscle pseudohypertrophy • Delayed puberty or precocious puberty • Treatment –same CH

36. Chronic thyroiditis Hashimoto disease Clinical presentation: • goiter with euthyroidism • Thoxic thyroiditis • Hypothyroidism with or without thyromegaly • Dysphagia, pain or pressure sensation in the neck, cough and headache have been reported

37. Diagnosis Hashimoto disease • T4 total and free, serum TSH • Biopsy • Antibodies test: antithyroglobulin antibodies to thyroperoxidase antimicrosomal test

38. Causes of thyrotoxicosis • Congenital: transient, neonatal Graves’ disease • Acquired: Graves’ disease • Functional adenoma • Thyroid cancer • TSH-secreting pituitary tumor • Jatrogenic

39. (Graves disease) • Diffuse toxity goiter - autoimmune pathology with prolonged elevation T3 & T4 and enlagment of Thyroid gland, and in 70% cases with ophthalmopathy

40. Graves disease (symptoms) • Hyperactivity, irritability, altered mood • Fatigue, weakness • Goiter • Tachycardia and ↑ pul’s pressure • Nervousness

41. Graves disease (symptoms) • Palpitations • Weight loss with ↑ appetite • Heat intolerants, increase sweating • Increased stool frequency • Thirst and polyuria • Oligomenorrea, loss of libido

42. Graves disease (sings) • Sinus tachycardia, atrial fibrillation • Tremor, hyperkinesis • Warm, moist skin • Palmar erythema, onycholysis • Hair loss • Muscle weakness & wasting • Heart failure, psychosis (rare)

44. Graves disease Ophthalmopathy • A feeling of grittiness & discomfort in the eye • Retrobulbar pressure or pain • Eyelid lag or retraction • Periorbital edema, chemosis, scleral injection

45. Graves disease Ophthalmopathy (c’d) • Proptosis • Extraocular muscle dysfunction • Exposure keratitis • Optic neuropathy

46. Treatment of thyrotoxicosis • Thionamids: mercasolyl 0.3-0.5 mg/kg divided 2 -3 times – 14-21 days , than supportive dose – 2.5-7.5 mg/daily 1 time • Β ab (anaprilin) 1-2 mg/kg divided 3 times • Euthyrosis – mercasolil 5-10 mg/daily with L-thyroxin 25-50 μg/daily • Surgical treatment

47. Thyroid storm (crisis) • Sudden onset • Fever • Profuse diaphoresis • Flushed warm skin • Tachycardia • Weakness, lethargy and confuson • Coma • Nausea, vomiting, diarrhea • Enlarge liver, jaundice

48. Thyroid storm (crisis) • NaJ 1-2 g daily IV immediately • Propylthiouracil 200-300 mg every 6 hours by nasogastric tube • Β ab (propranolol) 0.1 mg/kg IV or 4 mg/kg orally • Dexamethasone 1-2 mg every 6 hours • Supportive: correction of dehydratation, antipyretics, digitalis to patients with cardiac failure

49. GOOD LUCK!