Cretinism and hypothyroidism in children are congenital or acquired thyroid disorders caused by thyroid hormone deficiency. Cretinism results from congenital absence or deficiency of thyroid secretion and causes physical deformities and intellectual disability. Hypothyroidism is acquired due to primary thyroid issues or problems with the hypothalamic-pituitary-thyroid axis. Both disorders are diagnosed through clinical features, laboratory tests showing low thyroid hormones and high TSH, and imaging exams. Treatment involves lifelong thyroid hormone replacement therapy via thyroid supplements to replace missing hormones and allow normal growth and development.

1. Cretinism &
Hypothyroidism in
Children
Dr.K.V.Giridhar
Associate Prof. of Pediatrics
GMC. Ananthapuramu, A.P.,
India.
9 May 2014 1

2. • cretinism: ’congenital disease’ due to ab
sence or deficiency of normal thyroid secre
tion, characterized by physicaldeformity, d
warfism, and mental retardation, and often
by goiter.
• Hypothyroidism: ‘acquired disease’ due
to primary and other various causes of
Thyraoid and
hypothalamo, pitutory,thyraoid axis
abnormaloties.

3. Etioliogy of Cretinism
CONGENITAL
Hypoplasia & mal-descent of
thyraoid
Familial enzyme defects
Iodine deficiency in pregnacy
(endemic cretinism)
Intake of ‘goitrogens’ during
pregnancy
Pituitary defects
Idiopathic

4. Etiology of Hypothyroidism
ACQUIRED
Iodine deficiency
Auto-immune thyroiditis
Thyroidectomy or RAI therapy
TSH or TRH deficiency
Medications (iodide & Cobalt)
Idiopathic

5. GOITROGENS
• DRUGS
Anti-thyroid
Cough medicines
Sulfonamides
Lithium
Phenylbutazone
PAS
Oral hypoglycemic agents

6. GOITROGENS
 FOOD
Soybeans
Millets
Cassava
Cabbage

7. THYROID HORMONES
Iodine & tyrosine, together form
both, T3 & T4 under TSH
stimulation, in thyroid gland.
When released into circulation T4
binds to:
Globulin(TBG)-75%
Prealbumin(TBPA)-20%
Albumin(TBA)- 5%

8. THYROID HORMONES (c’d)
Less than 1% of T4 & T3 is free in
plasma.
T4 is deiodinated in the tissues to
either T3 (active)
At birth T4 level approximates maternal
level, but increases rapidly during the
first week of life.
High TSH in the first 5 days of life can
give false positive neonatal screening for
‘hypothyroidism’.

9. Thyroid stimulating Hormone
(TSH)
 Is a Glyco-protein.
 Secreted by the anterior pituitary
under influence of TRH(TSRH)
It has trophic effect on thyroid
gland
 It also stimulates, iodine
trapping, oxidation, organification,
coupling and proteolysis of T4 &
T3.

10. TSH (c’d)
 T4 & T3 are feed-back regulators of
TSH
 TSH is stimulated by a-adrenergic
agonists
 TSH secretion is inhibited by:
Dopamine
Bromocreptine
Somatostatin
Corticosteroids

11. Hypothalamo, pituitary, thyraoid
Axis
Pituitary gland
Thyroid gland
Hypothalamus
T3
T4
TRH
TSH

12. THYROID HORMONES (c’d)
Acute & chronic illnesses
b-adrenergic receptor blockers
Starvation & severe PEM
Corticosteroids
Propylthiouracil
High iodine intake (Wolff-Chaikoff
effect)
Conversion of T4 to T3 is decreased by:

13. THYROXINE (c’d)
Premature infants
Hypo pituitarism
Nephrotic syndrome
Liver cirrhosis
PEM
Protein losing enteropathy
Total T4 level is decreased in:

14. THYROXINE (c’d)
Steroids
Phenytoin
Salicylates
Sulfonamides
Testosterone
Maternal TBIgs.
Drugs, which decrease Total T4:

15. THYROXINE (c’d)
Acute thyroiditis
Acute hepatitis
Estrogen therapy
Clofibrate
iodides
Pregnancy
Maternal TSH
Total T4 is increased with:

16. FUNCTIONS OF THYROXINE
 Thyroid hormones are essential for:
Linear growth & pubertal
development
Normal brain development & function
Energy production
Calcium mobilization from bone
Increasing sensitivity of b-
adrenergic receptors to
catecholeamines

17. CLINICAL FEATURES
Birth weight > 4 kg
Open posterior fontanel
Nasal stuffiness & discharge
Macroglossia
Constipation & abdominal
distension
Feeding problems & vomiting

18. CLINICAL FEATURES (c’d)
Non pitting edema of limbs
Coarse features
Umbilical hernia
Hoarseness of voice
Anemia
Decreased physical activity
Prolonged (>3 weeks) neonatal
jaundice

19. CLINICAL FEATURES (c’d)
Dry, pale & mottled skin
Low hair line & dry, scanty hair
Hypothermia & peripheral cyanosis
Hypercarotenemia
Growth failure
Retarded bone age
Stumpy fingers & broad hands

20. CLINICAL FEATURES (c’d)
Skeletal abnormalities:
Infantile proportions
Hip & knee flexion
Exaggerated lumbar lordosis
Delayed teeth eruption
Under developed mandible
Delayed closure of anterior
fontanel

21. OCCASIONAL FEATURES
Overt obesity
Myopathy & rheumatic pains
Speech disorder
Impaired night vision
Sleep apnea (central &
obstructive)
Anasarca
Achlorhydria & low intrinsic
factor

23. OCCASIONAL FEATURES (c’d)
Decreased bone turnover
Decreased VIII, IX & platelets
adhesion
Decreased GFR & hyponatremia
Hypertension
Increased levels of CK,LDH & AST
Abnormal EEG & high CSF protein
Psychiatric manifestations

24. CLINICAL FEATURES (c’d)
 Neurological manifestations
Hypotonia & later spasticity
Lethargy
Ataxia
Deafness + Mutism
Mental retardation
Slow relaxation of deep tendon
jerks

25. ASSOCIATIONS
Autoimmune diseases
Diabetes Mellitus
Cardiomyopathy & CHD
Galactorrhoea
Muscular dystrophy + pseudo
hypertrophy (Kocher-Debre-
Semelaigne Syndrome)

26. DIAGNOSIS
Early detection by neonatal
screening
High index of suspicion in all
infants with increased risk
Overt clinical presentation
Confirm diagnosis by appropriate
lab and radiological tests

27. LABROTARY TESTS
Low (T4& T3)
High TSH
High serum cholesterol & carotene levels
Anaemia (normo, micro or macrocytic)
High urinary creatinine/hydroxyproline
ratio
CXR: cardiomegaly
ECG: low voltage & bradycardia

28. IMAGING TESTS
 X-ray films can show:
Delayed bone age or epiphyseal
dysgenesis
Anterior beaking of vertebrae
Coxavara & coxa plana
 Thyroid radio-isotope scan
 Thyroid ultrasound
 CT or MRI

30. THYROID FUNCTION TESTS
(c’d)
 Specific Tests:
Thyroglobulin level
Thyroid Stimulating Immunoglobulin
Thyroid antibodies
Thyroid radio-isotope scan
Thyroid ultrasound
CT & MRI
Thyroid biopsy

31. TREATMENT
L-Thyroxin is the drug of choice.
Start with small dose.
Dose is 10 mg/kg/day in infancy.
In older children start with 25
mg/day
and increase by 25 mg every 2
weeks till required dose.
Monitor clinical progress & hormones
level

32. TREATMENT(c’d)
 Life-long replacement therapy
 5 types of preparations are
available:
L-thyroxin (T4)
Triiodothyronine (T3)
Synthetic mixture T4/T3 in 4:1 ratio
Desiccated thyroid (38mg T4 & 9mg
T3/grain)
Thyroglobulin (36mg T4 & 12mg
T3/grain)

33. PROGNOSIS
Depends on:
Early diagnosis
Proper counselling
Strict diet control
Careful monitoring
Compliance

34. PROGNOSIS
 Is good for linear growth & physical
features even if treatment is
delayed, but for mental and intellectual
development early treatment is crucial.
 Sometimes early treatment may also
fail, to prevent mental sub normality
due to severe intra-uterine deficiency
of thyroid hormones

35. THANKYOU
9 May 2014 35