Thyroid Gland Diseases in Children

Riga OlenaKhNMU

Excretion of iodine ( in urine)

100-200 μg/l – normal level 201-299 μg/l – increase level > 300 μg/l - increase of intake in

food Deficiency: < 20 μg/l – severe 20-49 μg/l - moderate 50-99 μg/l - mild

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

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.

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

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

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

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

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

Diagnostic of Thyroid gland disease

Serological tests:*Markers of autoimmune disease

(antibodies to thyroglobulin, thyroperoxidase, to TSH-receptors)

*Markers of cancer (thyroglobulin, calcitonin)

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

Functional condition of Thyroid influence may be as

Euthyroidism Hypothyroidism hyperthyroidism

Нypothyroidism

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

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

Classification of hypothyroidism

OnsetCongenital Acquired (rare)

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

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

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

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

SIGNS OF CONGENITAL HYPOTHYROIDISM

Skin mottling and Dry skinUmbilical hernia and Distended abdomen

JaundiceMacroglossia

Large fontanels Wide sutures Hoarse cry

Muscle HypotoniaSlow reflexes

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

DIAGNOSTIC STUDIES IN HYPOTHYROIDISM

Thyroid scan – 99mTc or 123 IT3 resin uptake

Bone ageTSH !!!Free T4 – if hypothalamic- pituitary

hypothyroidism suspected TBG – if TBG deficiency suspectedAnti-thyroid antibodies – if history of

maternal thyroiditis

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

Biochemical hallmarks of CH

Other: Elevated serum cholesterol Elevated creatinphosphokinase Hyponatriemia

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)

Treatment L-thyroxin

Preterm 8 – 10 μg/kg 0-3 mo 10 – 15 μg/kg 3-6 mo 8 – 10 μg/kg 6-12 mo 6 – 8 μg/kg 1-3 years 4 – 6 μg/kg 3-10 years 3 – 4 μg/kg 10-15 years 2 – 4 μg/kg > 15 years 2 – 3 μg/kg

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

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

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

SIGNS OF ACQUIRED HYPOTHYROIDISM

Short stature Decreased growth velocity Increased upper to lower segment

ratio Delayed dentition Myxedema or mildly overweight Goiter

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

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

Diagnosis Hashimoto disease

T4 total and free, serum TSH Biopsy Antibodies test: antithyroglobulin antibodies to

thyroperoxidase antimicrosomal test

Causes of thyrotoxicosis

Congenital: transient, neonatal Graves’ disease

Acquired: Graves’ disease Functional adenoma Thyroid cancer TSH-secreting pituitary tumor Jatrogenic

(Graves disease)

Diffuse toxity goiter - autoimmune pathology with prolonged elevation T3 & T4 and enlagment of Thyroid gland, and in 70% cases with ophthalmopathy

Hyperactivity, irritability, altered mood

Fatigue, weakness Goiter Tachycardia and ↑ pul’s pressure Nervousness

Graves disease (symptoms)

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

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

Graves disease Ophthalmopathy

A feeling of grittiness & discomfort in the eye

Retrobulbar pressure or pain Eyelid lag or retraction Periorbital edema, chemosis,

scleral injection

Graves disease Ophthalmopathy (c’d)

Proptosis Extraocular muscle dysfunction Exposure keratitis Optic neuropathy

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

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

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

GOOD LUCK!