Download Hypothyroidism

Hypothyroidism
Eric Sherman
Pediatric Endo Fellow
Captain, USAF, MC
•
•
•
•
Who has ordered thyroid function tests (TFT)?
Who has made decisions based on the results?
Who has been confused by the results?
Who has referred someone to peds endo for
abnormal TFTs?
• Who follows patients with hypothyroidism
without endocrine assistance?
Causes of hypothyroidism
• Congenital – 1 in 4000 live births
• Acquired
• Most common cause world wide??
Causes of congenital
hypothyroidism (CH)
•
•
•
•
Thyroid dysgenesis
Thyroid dyshormonogenesis
Central hypothyroidism
Transient hypothyroidism
1:4000
1:40,000
1:100,000
1:40,000
Sperling
Signs/symptoms of CH
Signs/symptoms of CH
Newborn Screen
• Mandatory in all 50 states
• If performed before 24 hours, must be
repeated at least one more time
• Screening TSH: DC
• Screening FT4: VA, MD, overseas samples
Figure 15-4. Postnatal TSH, T4, T3, and rT3 secretion in the full-term and
premature infant in the first week of life (modified from Fisher DA: Disorders of the
thyroid in the newborn and infant. In: Sperling M (ed) Pediatric Endocrinology, WB
Saunders Co., Philadelphia, 51, 1996).
Positive newborn screen
• Confirmatory serum TSH and FT4 ASAP
• Call pediatric endocrinology
• Start Synthroid at 10-15 micrograms/kg/day
(50 micrograms once daily in term infants)
Example of MD newborn screen
• T4
10.8 (>7.0)
• T4 result is less than the 10th percentile for
this run. A TSH has been performed on this
specimen to complete the thyroid testing.
TSH result is 74.9 uIU/mL (<28.5 uIU/mL).
Consultation with a pediatric
endocrinologist  and further serum
thyroid studies are recommended.
How do you give Synthroid?
• Pill crushed
• Give with water or formula on a spoon, not
in bottle or syringe
• Avoid soy formula (absorption issues)
• May double dose if previous day’s dose is
missed
Follow up
• TSH and FT4 ever 1-2 months during year 1
• Every 3-6 months from ages 1-3
• Every 6-12 months from 3 until patient
stops growing
• Goal: bring FT4 into high normal range as
rapidly as possible (TSH may remain
elevated in 10% of patients)
Why treat CH?
• Average IQ 76 in pre newborn screen era
• Untreated patients lose an average of 1-2 IQ
points per month until age 2
• 40% of untreated patients require special
education in school
• Data suggests that treatment should be
initiated within 2 weeks (PREP says 3
months)
Long term consequences w/ treatment
•
•
•
•
Sensorineural hearing loss
Decline in verbal IQ
Head circumference 1 SD above the mean
Normal height and weight
Goitrogens
•
•
•
•
•
Cabbage, kale and other cruciferous veggies
Soybeans
Animal fodder
Lithium
Amiodarone
Hashimoto’s (chronic lymphocytic)
thyroiditis
• Most common cause of goiter in children
over 6
• F>M, family history in 30-40%
• More common in Down’s and Turner’s
syndrome
Other S/S
•
•
•
•
Cold intolerance
Fatigue
Relative bradycardia
Unexpected weight gain (usually this is not
the thyroid’s fault)
• Goiter in 2/3 of cases
Associated illnesses
• 25-30% of Type I diabetics have +
antibodies and 10% have elevated TSH
• Occasionally seen with celiac disease, JRA
and IBD
• Can be part of autoimmune syndromes like
APS type 1
Diagnosis
• Elevated TSH and low or normal FT4
• Anti-TPO and/or anti-TG antibodies in 9095% of patients
• TPO more sensitive and specific
• Ultrasound not a part of routine screening
Treatment
• Synthroid 100 micrograms/m2/day
• Profoundly hypothyroid patients undergoing
treatment can present with ???
• Follow TSH to ensure adequate treatment
Untreated
•
•
•
•
Final adult height decreased
Progressive thyroid enlargement
Occasional significant pituitary enlargement
Increased risk of thyroid cancer (even in
treated patients)
On a routine annual evaluation, a 13 year old girl from the
Midwest is found to have a diffusely enlarged thyroid gland
that is approximately 3 times the normal size according the
World Health Organization criteria. She is active, healthy,
clinically euthyroid, and has no other abnormalities on
physical examination. The family history discloses that two
maternal aunts and two cousins each were told that they had a
"goiter." Among the following, the most likely cause of this
patient's thyroid enlargement is:
A. Adolescent goiter
B. Autoimmune thyroiditis
C. Familial thyroid dyshormonogenesis
D. Nutritional deficiency goiter
E. Thyroid neoplasia
On a routine annual evaluation, a 13 year old girl from the
Midwest is found to have a diffusely enlarged thyroid gland
that is approximately 3 times the normal size according the
World Health Organization criteria. She is active, healthy,
clinically euthyroid, and has no other abnormalities on
physical examination. The family history discloses that two
maternal aunts and two cousins each were told that they had a
"goiter." Among the following, the most likely cause of this
patient's thyroid enlargement is:
A. Adolescent goiter
B. Autoimmune thyroiditis
C. Familial thyroid dyshormonogenesis
D. Nutritional deficiency goiter
E. Thyroid neoplasia
Among the following, the most sensitive laboratory test to
diagnose primary hypothyroidism is measurement of serum:
A. Free T4
B. Thyroglobulin
C. Thyroid antibodies
D. Total T3
E. TSH
Among the following, the most sensitive laboratory test to
diagnose primary hypothyroidism is measurement of serum:
A. Free T4
B. Thyroglobulin
C. Thyroid antibodies
D. Total T3
E. TSH
An 8-year-old girl has a 2 year decline in growth velocity, as
determined by plotting her height on a standard growth curve.
At age 6 years, her height was at the 60th %; at age 7 years, it
was at the 40 %; at age 8 years, it was at the 10th %. Her
parents are of average height. Her history is otherwise
unremarkable, and physical exam reveals no abnormalities,
although her thyroid gland cannot be palpated. The pair of
laboratory tests that would best help explain the cause of this
patient's recent growth retardation is:
A. Free T4 and T3
B. Growth hormone and blood urea nitrogen
C. Thyroid ultrasonography and technetium pertechnate scan
D. T4 and free T4
E. TSH and free T4
An 8-year-old girl has a 2 year decline in growth velocity, as
determined by plotting her height on a standard growth curve.
At age 6 years, her height was at the 60th %; at age 7 years, it
was at the 40 %; at age 8 years, it was at the 10th %. Her
parents are of average height. Her history is otherwise
unremarkable, and physical exam reveals no abnormalities,
although her thyroid gland cannot be palpated. The pair of
laboratory tests that would best help explain the cause of this
patient's recent growth retardation is:
A. Free T4 and T3
B. Growth hormone and blood urea nitrogen
C. Thyroid ultrasonography and technetium pertechnate scan
D. T4 and free T4
E. TSH and free T4
You receive notice that a male infant in your practice had an
elevated TSH level on newborn screening. The most
important laboratory test to obtain immediately is a measure
of:
A. Free T4
B. Thyroglobulin
C. Thyroid antibody
D. Total T3
E. Thyroid stimulating hormone
You receive notice that a male infant in your practice had an
elevated TSH level on newborn screening. The most
important laboratory test to obtain immediately is a measure
of:
A. Free T4
B. Thyroglobulin
C. Thyroid antibody
D. Total T3
E. Thyroid stimulating hormone
Although the prognosis for normal intellectual and neurologic
function and linear growth can be excellent for children who
have congenital hypothyroidism, delaying treatment beyond
which of the following ages is likely to be associated with
impairments:
A. 24 hours
B. 2 weeks
C. 3 months
D. 6 months
E. 1 year
Although the prognosis for normal intellectual and neurologic
function and linear growth can be excellent for children who
have congenital hypothyroidism, delaying treatment beyond
which of the following ages is likely to be associated with
impairments:
A. 24 hours
B. 2 weeks
C. 3 months
D. 6 months
E. 1 year
A 15-year old female presents with an asymptomatic goiter.
She has type I diabetes that was diagnosed at age 7 years. Of
the following, the study that is most likely to be used to
establish the diagnosis is:
A. Measurement of antiperoxidase antibodies
B. Needle biopsy of the thyroid
C. Technetium thyroid scan
D. Thyroid binding globulin level
E. Ultrasonography of the thyroid
A 15-year old female presents with an asymptomatic goiter.
She has type I diabetes that was diagnosed at age 7 years. Of
the following, the study that is most likely to be used to
establish the diagnosis is:
A. Measurement of antiperoxidase antibodies
B. Needle biopsy of the thyroid
C. Technetium thyroid scan
D. Thyroid binding globulin level
E. Ultrasonography of the thyroid
You are evaluating a 15-year-old girl who is concerned about
being overweight. Physical examination reveals a weight of
90.9 kg (>95%) and height of 170 cm (90%). Findings on the
remainder of the examination, including the thyroid gland, are
normal. The total T4 concentration is 3.1 mcg/dL (normal is
5.6-11.7) and the TSH level is 4.5 microIU/mL (normal 0.66.3). Repeat studies confirm these results, and a 3,5,3triiodothyronine (T3) resin uptake is 52% (normal 25-35%).
Of the following the most likely diagnosis is:
A. Hashimotos thyroiditis
B. Hyperthyroidism
C. Primary (thyroid) hypothyroidism
D. Secondary (central) hypothyroidism
E. Thyroid binding globulin deficiency
You are evaluating a 15-year-old girl who is concerned about
being overweight. Physical examination reveals a weight of
90.9 kg (>95%) and height of 170 cm (90%). Findings on the
remainder of the examination, including the thyroid gland, are
normal. The total T4 concentration is 3.1 mcg/dL (normal is
5.6-11.7) and the TSH level is 4.5 microIU/mL (normal 0.66.3). Repeat studies confirm these results, and a 3,5,3triiodothyronine (T3) resin uptake is 52% (normal 25-35%).
Of the following the most likely diagnosis is:
A. Hashimotos thyroiditis
B. Hyperthyroidism
C. Primary (thyroid) hypothyroidism
D. Secondary (central) hypothyroidism
E. Thyroid binding globulin deficiency
?Questions?