Growth and Puberty Flashcards
Expected weight gain in children
0-3 months: 180g/week 3-6 months: 120g/week 6-9 months: 80g/week 9-12 months: 70g/week <10% weight loss in first weeks which recovers
dDx faltering growth
Inability to feed Malabsoprtion Chronic disease Syndromic Child abuse/malnutrition Diabetes
dDx the short child
familial short stature endocrine nutrition malabsoption chronic illness steroid excess syndromic constitutional delay
Features constitutional delay
Variation of normal with a delay in puberty onset
Usually a family history with normal growth achieved by adulthood
Normal bone age on Xray
Ix short stature
Height and weight growth chart
wrist xray and bone age
Causes hypothyroid
Usually autoimmune thyroiditis, growth failure, excess weight gain, rapid catch up growth associated with rapid puberty and overall decreased final height, raised TSH
Causes GH deficiency
congenital midfacial/midline defects, craniopharyngioma, hypothalamic tumour, trauma, Laron syndrome (defective GH receptors)
Syndromes with short stature
turners syndrome, down’s syndrome, russell-silver, praa-willi, cystic fibrosis, williams, McCne-Albright
Features normal head growth
Largest proportion of head growth occurs before age 2 with complete adult head size achieved by age 5. Fontanelles close at: posterior by 8 weeks; anterior by 12-18 months
Features microcephaly
Head circumference below the second decile
May be developmentally normal .e.g. Familial
Pathological: congenital infection, autosomal recessive condition associated with developmental delay, acquired form insult to the developing brain, fetal alcohol syndrome, patau
Features macrocephaly
Head circumference above to 98th decile May be tall stature or familial Sign of raised ICP: chronic subdural haemorrhage, turmou, neurofibromatosis Cerebral gigantism CNS storage disorder
Imaging in abnormal head growth
Should be investigated by: US if fontanelles are open; MRI if fontanelles are closed
Features assymetrical head growth
Can result from growth imaba;lance although should remain on same head circumference centile Occipital plagiocephaly (flattening of the back of the head) commonly due to sleeping/lying position, and resolves when child becomes mobile. Plagiocephaly is seen in children with hypotonia/immobility .e.g. SMA due to lack of posturing changes Preterm infants develop flat sides due to lying incubators: may be improved with soft surfaces and changing head positioning regularly
Features carniosynostosis
Skull bone suture start to fuse during infancy, ad complete fuse by childhood
Leads to distinctive head shape
Typically affects sagittal suture causing a long narrow skull
Generalised craniosynostosis is a feature of crouzon syndrome : requires craniofacial reconstruction prevent visual loss and cerebral damage
Fuse suture felt as a palpable ridge
Diagnosis confirmed by Xray or CT
dDx premature sexual development
True precocious puberty
Pseudoprecocious puberty
Thelarche
Padrenerche
Features True precocious puberty
Premature activation of the HPA axis (gonadotropic dependant)
Females very sensitive to gonadotropins so commonly affected by precocious puberty
US of ovaries shows progress of puberty and uterine change from infantile tubular shape to pear shape and thickening of endometrium
Examination of tests bilateral enlargement >4mm suggests true PP
Mx true precocious puberty
In females delay of menarch by GnRH analogues
Features pseudoprecocious puberty
Secretion of estrogen and testosterone by tumor of adrenal gland, testes, or ovaries
Abnormal dissonant sequence
Pathological causes are rare: congenital adrenal hyperplasia/adrenal tumour
Present with axillary hair, odor and acne before breast development
Testes are insensitive to gonadotropins hence true precocious puberty is uncommon.
Prepubertal testes suggests pseudo PP
Unilateral enlargement of the testes suggests gonadal tumors
Use of androgen/oestrogen production inhibitors
Features thelarche
Preamture isolated breast development Usually females between 6 months and 2 years Does not progress past tanner stage 3 Usually self limiting] Absence of other pubertal features
Features padrenerche
Premature pubic hair development, without other signs of sexual development
Due to accentuation of normal maturation of androgen production by the adrenal gland
6-8 years of age
More common in asian and black children
Associated with increase in growth rate and bone age (12-18 months advance of actual age)
Usually self limiting
Virilization suggests nonclassical congenital adrenal hyperplasia or an adrenal tumour
Girls with premature pubarche are at risk of PCOS
dDx delayed sexual development
Constitutional delay Systemic disease HPA disorder Acquired hypothyroid Chromocomal abnormalities Androgen insensitivity syndreme
Features androgen insensitivity syndrome
LH high, testosterone normal
X linked recessive condition
End organ resistance to testosterone
Genetically male children have a female phenotype
Primary amenorrhoea
Undescended testes causing groin swelling
Breast development may occur (conversion of testosterone to oestradiol)
46XY genotype
Mx Androgen insensitivity syndrome
Counselling and raise child as female
Bilateral orchiectomy to reduce testicular cancer
Oestrogen therapy
Features Kallmans
Hypogonadotropic hypogonadism: LH/FSH/testosterone inappropriately low
Associated with anosmia
Usually X linked recessive
Failure of migration of GnRH secreting neurons
Association with cleft palate/lip, visual/hearing defects
