thyroid disorders lecture for under graduates

1. Thyroid Disorders
in
Children
By: Dr. Sumera Akram
SR Peadiatrics
SMC
Classification,
Epidemiology, Etiology Clinical
Features, Complications,
Management, Prognosis and
Prevention

5. Causes of Hypothyroidism
hypothyroidism
Primary :
thyroid
Dyshormonogenesi
s: iodine transport
defect, peroxidase
defect,
thyroglobulin
defect
Iodine
deficiency
Thyroid
gland
agenesis
Thyroid
destruction:
autoimmune,
medications/ra
diation
Secondary
: pituitary
Tertiary:
hypothala
mus

6. Case Scenario
• An 2 months old baby presents to the OPD with the
complaints of poor feeding and noisy breathing. Baby was
born by SVD and was normal at birth. He remains
constipated and passes stool only when a suppository is
given.
• On examination, weight of the child is 4 kg. His mouth is
open and tongue is visible. His abdomen is distended with
gases and umbilical hernia is seen. He has dry skin.
• What is your diagnosis in this baby ?

7. Congenital Hypothyroidism
1 in 2000 children born with congenital hypothyroidism

8. Causes of Congenital Hypothyroidism
• Thyroid Dysgenesis – 90 % of cases
- most common cause
• Thyroid dys-hormonogenesis
- genetic autosomal recessive inheritance
• Iodine deficiency
- mother is having iodine deficiency and goiter
•TSH deficiency (very rare)
• Hypothalamic-pituitary hypothyroidism–
Anencephaly, holoprosencephaly,
•Transient hypothyroidism–Maternal TRAB–Maternal
ingestion of goitrogen
• Drugs
• Iodine excess

9. Signs and symptoms in Newborns andInfants
• Lethargy, sleepiness and poor activity
• Delayed milestones of development
• Poor feeding
• Constipation
• Macroglossia
• Large open fontanelle
• Hoarse cry
• Dry skin
• Distended abdomen and Umbilical
hernia
• Neonatal goiter
• Prolonged jaundice
dys
-

10. Case Scenario
• A 6 years old boy presents to the OPD with
the complaints of delayed mental
development. Child started walking at 3 years
of age and speaks only few words. He keeps
sitting and is not active. He remains
constipated since birth.
• On examination, weight of the child is 15 kg
and his height is 95 cm. His face is puffy with
depressed bridge of nose and a large visible
tongue. He has dry skin and cold hands. He has
a hoarse voice
• What is your diagnosis in this child ?

11. Childhood Hypothyroidism
(Congenital orAcquired)
5.4 % population affected with hypothyroidism
F > M

12. Causes of Childhood Hypothyroidism

13. • Lethargy/somnolence
• Depression
• Modest Weight Gain
• Cold Intolerance
• Hoarseness
• Dry skin
• Constipation (↓ peristaltic
activity)
• Arthralgias or myalgias (worsened
by cold temps)
• Brittle Hair
• Menstrual irregularities
Symptoms –
• Dry, pale, course skin with
yellowish tinge
• Periorbital edema
• Puffy face and extremities
• Sinus Bradycardia
• Diastolic HTN
• ↓ Body temperature
• Delayed relaxation of reflexes
• Megacolon (↓ peristaltic
activity)
• Pericardial/ pleural effusions
• Congestive heart failure
• Non-pitting edema
• Myopathy
• Short stature
Examination
Signs and Symptoms of Acquired
Hypothyroidism

14. Hashimoto Thyroiditis

15. IDD
Iodine DeficiencyDisorders

16. RoleofIodine
• essential for the synthesis of Thyroid
Hormones
• Daily Requirement of Iodine - RDA 100 ug /
day
• A deficiency in thyroid hormone synthesis
or intake leads to increased TSH
production. Increased TSH causes
increased cellularity and hyperplasia of the
thyroid gland in an attempt to normalize
thyroid hormone levels. If this process is
sustained, a goiter is established
(enlargment of thyroid gland)

17. Importance of Iodine in children

18. Cretinism (congenital hypothyroidism)
• most serious IDD
• occurs when a pregnant women is
severely iodine deficient usually has a
goiter
• Two main types of cretinism:
Neurological cretinism
• mental retardation,
• deaf mutism,
• squint,
• spastic diplegia,
• disorders of stance and
gait.
Myxoedematous cretinism
• mental retardation (although
less severe than in neurological
cretinism),
• dwarfism,
• hypothyroidism with physical
symptoms (e.g., coarse and dry
skin, husky voice, delayed sexual
maturation).

19. Endemic Goiter
• Iodine deficiency
• Endemic goitre occurs when the prevalence of
thyroid enlargement in the population of an
area exceeds 10%
• occurs in those areas where the iodine
content of the soil is so low that insufficient
iodine is obtained through food and water.
(common in hilly areas worldwide )

20. Lab Diagnosis
• Bone age – delayed
X-ray Knee in newborns (absent knee epiphyseal centers)
X-ray Wrist in children
• Radio-isotope scan for thyroid (detects thyroid tissue)
• Anti-thyroid antibodies (anti TPO antibodies)– in auto-immune
thyroiditis
• CBC: normocytic or macrocytic anemia
• ECG : bradycardia with small QRS complexes
TSH
FREE T4
FREE T3
•Specific
tests:

21. TreatmentofHypothyroidism
• Treatment must be started in first 2 weeks of life to
prevent brain damage
• Thyroxine tabets orally : levothyroxine
• Drug is given empty stomach usually in the morning
• Daily dose should not be missed
• neonate:10-15mcg/kg
• 6-12 month:6-8mcg/kg
• 1-6 yrs :5-6 mcg/kg
• 6-12 yrs:4-5 mcg/kg
• Adult: 100-150 mcg

22. Monitoring of Treatment
Clinical Examination:
• Linear growth
• Weight gain
• Developmental progression
Investigations:
• serum TSH, T3, T4 levels every 3-6 months

23. How to prevent Hypothyroidism ?
Preventionsavesfrommentalhandicap
• Iodine deficiency
- Community education
- Iodine supplementation (Iodised salt)
• Congenital Hypothyroidism
- Early diagnosis and treatment
- Newborn TSH screening programs (TSH assessed at 7
days of age)
• Acquired Hypothyroidism
- High index of suspicion for diagnosis and treatment

25. Complication of Overtreatment with Thyroxine
/ Hyperthyroidism

26. Hyperthyroidism
Transient:
Neonatal
thyrotoxicosis
Persistent:
Graves’
disease

27. Neonatal Thyrotoxicosis
•Only occur with 5% of
thyrotoxic mothers.
•Severity consistent in
future pregnancies.
•20% mortality if
untreated.
•Associate with cranial
synostosis and
learning difficulties, if
not treated.

28. Graves Disease
•T-cell dependent autoimmune
disease
•HLA association
•TRSAbs are detectable in serum
Ophthalmopathy
Dermopathy
Acropachy

29. Signs and Symptoms of Hyperthyroidism
Symptoms:
Jittery,
shaky,
nervous
Difficulty
concentrati
ng
Emotional
lability
Insomnia
palpitations,
Feeling Hot
•Examination
Eye findings
(20%)
Goiter
Thyroid bruit
or thrill
Tachycardia:
Sinus
Tachycardia,
Atrial
Fibrillation–
Flow murmur
Systolic
hypertension

30. Diagnosis and Treatment
INVESTIGATIONS:
TSH level usually < 0.05
µu / ml
95 % of cases, high FT4
& FT3
Thyroid receptor (TRAB)
are usually elevated at
diagnosis
Thyroid scan

31. Treatment of Hyperthyroidism
Neonatal
Thyrotoxicosis
• Lugol’s iodine
• Propranolol
• Carbimazole(methimazol
e) will take several days
to have an effect on T4
synthesis
Hyperthyroidism:
• β-blockers(symptom control)–Propranolol
• Antithyroid Drugs: Propylthiouracil(not
available in pakistan and risk of hepatic
complications)Methimazole (10X more potent)
• 131-RAIA: C/I in Pregnancy and lactation,
moderate severe Graves’ ophthalmopathy
• Surgery(sub-total
thyroidectomy):Indications •Patient
preference •Large or symptomatic goiters
•When there is question of malignancy–Need
to be euthyroid prior to surgery •Permanent
hypoparathyroidism •Recurrent laryngeal
nerve problems •Permanent hypothyroidism

32. Quiz/ summary
 Most abundunt form of thyroid
hormone?
 Active form of thyroid hormone ?
 Congenital hypothyroidism due to
iodine deficiency is called ?
 Drug of choice in hypothyroidism ?
 X-ray finding of hypothyroidism ?
 once drug started the followup
measurement of TSH, T4 and T3 are
done at what time interval ?
•T4
•T3
• CRETINISM
•LEVOTHYRO
XINE
• DELAYED
BONE AGE
• EVERY 3-6
MONTHLY

33. Signs and Symptoms of Hypothyroidism

34. Thank you