short stature Flashcards
Case
CC: short stature
J.O.M. 1 yo old male, sees you for the first time with the chief
complaint of short stature.
Pertinent in the birth history is history of normal birthweight and
length with note of prolonged jaundice of 1 month, with feeding
difficulties, poor cry and sluggishness.
Newborn screening: (+)
Developmental Hx: Motor: cannot sit independently; Language:
does not babble; Psychosocial: not laughing in playful situations.
Cognitive: not searching for dropped objects.
PE:
Weight for age below +2 , Height for age below -3
lethargic , sallow complexion (+) dry mottled, cool skin
coarse facial features (+) macroglossia (+) large fontanelles
(+) heart murmur
(+) umbilical hernia
(+) hypotonic extremities
Lab Results:
CBC: Hgb 80 Hct .21 PBS: MCV 120
T4 (low) TSH (high)
Thyroid scan: Lingual thyroid
Bone scan: delayed
Primary Working Impression:
Congenital Hypothyroidism
Basis:
Typical signs and Symptoms at Birth/ Hx
o Decreased activity
o Poor feeding and weight gain
o Small stature or poor growth
o Prolonged Jaundice
o Decreased stooling or constipation
o Developmental delay
o Hypotonia
o Hoarse cry
o NBS: (+) CH
Physical findings of hypothyroidism may or may not be present at
birth. Signs include the following:
o Coarse facial features
o Macroglossia
o Large fontanelles
o Umbilical hernia
o Mottled, cool, and dry skin
o Cardiac anomalies
o Pallor
o Myxedema
o Goiter
Lab Results:
Diagnosis of primary hypothyroidism is confirmed by
demonstrating decreased levels of serum thyroid hormone (total
or free T4) and elevated levels of thyroid-stimulating hormone
(TSH).
Bone aging: delayed
CBC: macrocytic anemia
Thyroid scan: ectopic lingual thyroid
What are the differentials?
Differentials:
- Cushing syndrome
Rule in:Excessive weight gain
Delayed bone aging
short stature
Rule out: Stigmata of Cushing’s
syndrome: moon
facies, buffalo hump,
hypertension, purple striae and
obesity
Normal T4, TSH
2.Genetic short stature
Down Syndrome
Rule in:Short stature
Rule out:flat nasal bridge,
folded or dysplastic ears,
transverse palmar
crease, upward-slanting
palpebral fissures
Noonan syndrome
Rule in:Short stature
Rule out:triangular-shaped
face,downward-slanting
eyes, ptosis, low-set
ears with thickened helices, high nasal bridge, pectus carinatum or
excavatum
Turner syndrome (for girls only)
Rule in: Short stature
Rule out: short and stocky
build, shield-shaped chest,
webbed neck, widely
spaced nipples, high
palate, short fourth
metacarpal, low posterior hairline
Prader-Willi
syndrome
Rule in: Short stature
Rule out: Obesity
hypogonadism
Hypopituitarism
Rule in: Short stature
Delayed bone aging
Deficiency of GH may be
accompanied by
hypoadrenalism and
hypothyroidism. Prolonged
neonatal jaundice is common
Rule out:
-Growth hormone
deficiency from hypopituitarism may cause micropenis, midface
hypoplasia, and midline
defects
-Infants with congenital defects of the pituitary or
hypothalamus usually present with neonatal emergencies such as apnea, cyanosis, or severe
hypoglycemia with or without
seizures
-Microphallus in boys provides
an additional diagnostic clue
Chronic illness/malnutrition
Most chronic systemic disease can cause a child to have short
stature. Like children ] with nutritional deficiencies they will often
have greater weight loss than stature loss. Common culprits are GI,
Renal, Cardiac, Pulmonary and Immunologic disease
Diagnostics for short stature
Diagnostics:
For this case: Congenital Hypothyroidism
o CBC
o free T4 and TSH
o bone age x-ray
Additional Work up for Short Stature:
o ESR
o LFTs
o urinalysis
o stool fat,
o karyotype
Management of short stature
Levothyroxine given orally is the treatment of choice. -
In neonates, the recommended initial starting dose is 10–15 μg/kg
(37.5 to 50 μg/24 hr).
Levels of T4or free T4 and TSH should be monitored at
recommended intervals (approximately monthly in the first 6 mo
of life, and then every 2–3 mo between 6 mo and 2 yr) and
maintained in the normal range for age.
Children with hypothyroidism require about 4 μg/kg/24 hr, and
adults require only 2 μg/kg/24 hr.
What is the approach to short stature?
Approach to Short Stature
1. Accurate measurement of length or height is essential.
- Plot the height in age and sex appropriate WHO and CDC
growth charts. - Is the height velocity impaired?
Height velocity – rate of increase in height over a period of time.
Height (cm) at Time 2 – Height (cm) at Time 1 x 12 = cm/yr
Number of months between Time 1 and 2
Where time 1 is preferably 6-12mos (at least 3-6 mos) from Time 2.
Decreased height velocity = <5cm/year from 2 yo to puberty (12yo) - Is the child’s growth within the range for the family?
Give the MPH formula
Give the laboratories short stature
Laboratories:
1. Bone age – Xray of L hand and wrist
- For those with N height velocity, height percentile or SD
within midparental height
- If >2SD below the mean for age = constitutional growth
delay or pathologic condition
Refer to specialist
Referral to specialist:
1. Growth velocity <5 cm (2 in) per year
2. Height-for-age curve has deviated downward across
two major height percentiles
3. Projected height more than 2 SD (10cm or 4in) below
midparental height
4. Bone age >2 SD below chronological ag
5. Children born SGA or with IUGR who do not catch up to
the growth curve by 2 years of age
6. No onset of puberty by 14 yo for boys or 13 yo for girls
7. Diagnosis of conditions approved for recombinant
growth hormone therapy
What are common causes of short stature?
- Measurement - One of the most common reasons for referral to
a pediatric endocrinology clinic is measurement error or inaccurate
plotting. - Endocrine – Hypothyroid, Cushing syndrome, Growth hormone
disorders - Systemic disease (GI, Renal, Cardiac, Pulmonary, Immunology)
- Nutritional
- Genetic syndromes
What is constitutional growth delay?
Children who have normal birth size but then gradually fall on the
growth charts. Both bone and dental age is delayed. At about three years of age growth starts to parallel the growth chart curves. The patient also enters puberty at a later age than his/her peers. They
can continue to grow until their late teens and early twenties (boys
only.) Family history is often positive for delayed puberty. Adult
height is normal.
What are the important findings in genetic short stature?
Children with genetic short stature also have a normal birth size.
During the first three years of life they fall on the growth chart.
They start to parallel the growth curves around three years of age.
However, they have normal bone and dental age and enter
puberty at a normal age. Final adult stature is short
Short stature – height/length >2SD below the mean for a particular
age or below 3rd percentile for age and sex according to the
population standard
What is pathologic short stature?
*Height is initially within normal range that starts falling off the height curve over time
*delayed bone age
*possible causes: Prenatal onset 9maternal infections and undernutrition, chromosome defects) & postnatal onset
(nutritional deficiency, chronic systemic disease, psychosocial deprivation)
What is constitutional growth delay?
*height is sustained at lower percentiles during childhood
*hallmark finding: delayed pubertal growth spurt
*Eventual normal final adult height is reached (catch up growth occurs late adolescence)
*often with history of similar growth pattern with family members
*delayed bone age (chronological age> bone age)
What is familial short stature?
*stays parallel to the growth curve
*significant number of family members who are short
*bone age is not delayed (chronological age=bone age)
Hormones Affecting Growth
- Growth Hormone
- Thyroid hormone – 1st 3 years of life
- Glucocorticoids
- Sex hormones
- Insulin – important fetal growth (infant of DM mom is
macrosomic)
Growth Hormone deificiency
HYPOPITUITARISM
- Deficiency of GH with or without deficiency of other
pituitary hormones
- Short stature due to lack of stimulation of long bone
growth
pathophysiology of GH deficiency?
Patho
- Damage to pituitary gland –> impaired hormone
production (GH, PRL, TSH, ACTH, LH, FSH) –> failure of
target glands and low target hormone levels (low T3,
T4, cortisol, sex hormones)
What are the clinical manifestations of GH deficiency?
CM
1. Congenital – if with severe defect of GH production,
height will fall >4 SD below the mean for length by 1 yo
2. Acquired – child is N initially and CM gradually appear
and progress
- Atrophy of adrenal cortex, thyroid and gonads result in
weight loss, asthenia, sensitivity to cold, and absence
of sweating
3. Severe growth failure, tendency for hypoglycemia,
micropenis, prolonged neonatal jaundice
4. Short and broad face, prominent frontal bone,
depressed nasal bridge, saddle-shaped nose,
underdeveloped mandible, short neck, high-pitched voice, well-proportioned extremities, small hands &
feet, delayed or absent sexual maturity
5. Delayed bone age
diagnostics
Dx
Dx is suspected with severe postnatal growth failure defined as
any of the ff:
- Height < 1st percentile for age and sex
- Height >2 SD below sex-adjusted mid-parental height
Height velocity is low relative to sex- and bone-aged matched
peers
1. GH levels – absent or low (<10 ug//L) in response to
stimulation or provocative test (rapid administration of
insulin, arginine, clonidine, levodopa, or glucagon)
2. TSH, T3, T4 – assess thyroid function prior to
provocative GH test as it is a pre-requisite for normal
GH synthesis
3. Cortisol, ACTH, gonadotropins, gonadal steroids –
necessary to examine other pituitary functions
4. Skeletal maturation/ bone age – delayed
5. Cranial MRI/CT – small anterior pituitary gland;
suprasellar calcification (if craniopharyngioma)
Management of GH deficiency
Mgt
1. Human GH (hGH) – should be started ASAP
- Maximal response occurs in the 1st yr of tx with growth
velocity usually above the 95th percentile for age
2. Criteria for stopping tx
- Decision by the patient that he/she is tall enough
- Growth rate <1 in/yr
- Bone age >14 yrs (F) and >16 yrs (M)
What is failure to thrive?
Abnormal pattern of weight gain defined by lack of
sufficient usable nutrition and documented by
inadequate weight gain over time
- Dec in velocity of weight gain leads to steady falling off
the expected weight curve on growth charts
- Weight faltering – less alarming/ negative
Etiology/Patho
- Results from inadequate usable calories necessary for
a child’s metabolic and growth demands
- Malnourished infants and young children who fail to
meet expected standards of growth
- related to environmental and psychosocial causes
- causes of insufficient growth:
o failure to ingest and utilize sufficient
calories
o malabsorption
o increased metabolic demands
- Environmental, GIT, Congenital, Infection, Metabolic,
Neurologic, Renal and Hematologic
- Symmetric FTT – (Wt, HT, HC) – long standing
malnutrition, chromosomal abnormalities, congenital
infection or teratogenic exposures
1. Organic FTT – growth failure is due to an acute or
chronic disorder that interferes with nutrient intake,
absorption, metabolism, or excretion or that increases
energy requirements
Red flags suggesting organic causes
Red flags suggesting organic causes
o Cardiac findings
o Developmental delay
o Dysmorphic features
o Failure to gain weight despite adequate
caloric intake
o Organomegaly/ LNE
o Recurrent or severe pulmonary, skin, or
urinary infection
o Recurrent vomiting, diarrhea, or
dehydration
What is non-organic FTT?
- Non-organic FTT – upto 80% of children with growth
failure do not have an apparent organic disorder;
growth failure occurs because of environmental
neglect (lack of food), stimulus deprivation or both
What are the clinical manifestations of FTT?
CM
1. Weight that falls or remains below the 3rd percentile
for age, or decreases 2 major percentiles on the chart
2. Less than 80% median height of the child
3. BMI for age below -3
4. decreased subcutaneous fat, decreased muscle mass,
dermatitis, hepatomegaly, cheilosis or edema
