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Thyroid Disease in Childhood and Adolescence, : - Coggle Diagram
Thyroid Disease in Childhood and Adolescence
Embryology
Develops from floor of Pharynx at 4 wks
Trvels inferiorly
Thyroglossal tract disappears - cystic elements may remain as thyroglossal duct cyst may have thyroid tissue
Diverticulum becomes bi-lobed and fuses with ventral aspect of 4th pharyngeal pouch
Organogenesis under genetic control
Transcription factors TTF1, TTF2 and Pax8 crucial
Thyroid Axis
Hypothalamus - TRH
Anterior Pituitary - TSH
Thyroid gland - Thyroid hormones
Manufacture of Thyroid Hormone
Active transport of iodide via iodine pump (TSH)
Iodide oxidised to iodine (TPO)
Iodine binds to tyrosine residues (organification) on thyroglibulin forms mono and diiodotyrosine (TPO & TSH)
Coupling T3 and T4
Protealytic enzyme T4 and T3
Under TSH control
Release of Thyroid Hormone
Lysosomal hydrolytic enzyme digest thyroglobulin
Thryoid hormone liberated
TH diffuses to blood
Binds to carrier proteins
Under TSH control
Function TH
Speed up metabolism
Essential for growth and mental development
Increased sensitivity of CNS and CVS to catecholamines
Disorders
Simple / Colloid Goitre
Clinically euthyroid
Palpable goitre - swelling of thyroid glands
Hypothyroidism
Congenital / aquired
Hyperthyroidism
Congenital Hypothyroidism
Incidence IRE
1/2,200
Causes
Primary Congeital Jhypothyroidism - 95%
Dysgenesis
Ectopic
Hypoplastic
absent
Ectopic
Dyshormongenesis / Enzyme defect
Central Congenital Hypothyroidism , Pituitary, Hypothalamic <5%
Isolated TSH deficiency or panhypopituitarism
Rare genetic mutations
TSHB
IGSF1
Iodine deficiency
Symptoms
• Sleepiness
• Poor Feeding
• Prolonged jaundice
• Constipation
• Hoarse cry
• FHx congenital hypothyroidism
• Maternal history of thyroid disease
Signs
• Jaundice
• Cold
• Large Tongue
• Coarse facies
• Large fontanelles
• Hypotonia
• Distended abdomen
• Umbilical hernia
• Slow reflexes
Diagnosis
• TSH (Increased generally)
• FT4 (low or normal)
• Xray knee
• Thyroid Ultrasound
• Technetium scan
• Careful clinical examination for congenital abnormalities
• Monitor hearing (risk x3 gen pop)
Treatment
L- Thyroxine
10-15mg/kg/day
Delayed Tx - Irreversible neurodevelopmental delatt
Exess tx - Craniosynostosis (premature fusion of sutures)
Prognosication Factors
1 Early detection and treatment
Screening program
Prevents irreversible developmental delay and optimises developmental outcome
Asap ideally before 2 wks
Severity
May be subtle cognitive and motor deficits
Adherance
Hypothyroidism in Older Children
Aetiology
Congenital
Autoimmune - Hasmimoto's
Associated w/ DM, addisons, trisomy21, TS
Post radiation
Pituitary, hypothalamic
Sick euthyroid syndrome
Clinical Features
Symptoms
• tiredness
• constipation
• cold intolerance
• slowing of growth +/- short stature
• ? poor school performance
• Delayed puberty (occ precocious), irregular periods
• History of SUCFE, other AI disease
• Family history
• Weight gain
Signs
• Myxoedatous facies
• short stature
• goitre
• obesity
• dry skin
• Increased body hair
• Pallor
• Vitiligo
• Proximal muscle weakness
Delayed reflexes
Puberty gen delay
Diagnosis
TSH
FT4
TPO
Treatment
Thyroxine 100μg/m2/day
Neonatal Hyperthyroidism
Epidemiology
Much less common than hypo
Transient
Maternal hx of Graves
Mother high TSI
Maternal ATD, RAI or surgery
May last months - antibodies - aggressive treatment
Aetiology
Autoimmune
Grave's
Hashitoxicosis
Autonomous thyroid nodule "hot spot"
McCune Albright (Somatic activating mutation)
Toxic adenoma
Hyperfunctioning papillary
Follicular carcinoma
TSH receptor activating mutation
TSH secreting Pituitary adenoma
Pituitary resistance to TH
Thyroiditis / abcess
Clinical Features
Symptoms
CNS
Behaviour
Poor school performance
Nervouse
GIT
Appetite
Weigth loss
Diarrhoea
Metabolic
Heat intolerance
Signs
Exophthalmos
Ptosis
Lid retraction
Tachycardia
Tremor
Brisk tendon relfexes
Increased growth and bone age
Investigations
FT3. FT4, TSH
TPO
TRAB
Ultra sound
Technetium scan
+/- TRH test
Baseline FBC and LFTs
Treatment
Thyrotoxicosis
Carbimazole
Avoid PTU - hepatotoxic
Longer tx duration increased remission rates
Definitive - Thyroid Ablation
Radio iodine over 10yrs
Total thyroidectomy in younger + large goitre
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