case : pregnant women with previous thyroidectomy , tsh test show that tsh level 500 (normal 0.5-5 mlu/L ) and undergone c/s , so how to deal with the child
Hypothyroidism :
how to diagnose hypothyroidism ?
by serum free T4
whats the cause of hypothyroidism ?
primary : the disease in thyroid gland itself
secondary : abnormalities in pituitary gland
tertiary : abnormalities in hypothalamus
hypothyroidism , congenital or acquired may associated with goiter
congenital hypothyroidism : 1 in 2000-4000 live birth , caused by dysgenesis (agenesis , aplasia ,ectopia ) or dyshormonogenesis (enzyme defects)
clinical manifestation : most infant with congenital hypothyroidism asymptomatic at birth , even if there complete agenesis of thyroid gland , due to transplacental passage of moderate amount of maternal T4 which provides fetal levels that are approximately 33% of normal birth , despite this maternal contribution of thyroxine , hypothyroid infant still have low few serum T4 and elevated tsh level , and this will be identified by newborn screening programs
so the clinician depend on neonatal screening tests for the diagnosis of congenital hypothyroidism
even more , laboratory errors occur and awareness of early symptom and signs must be maintained
so ,
what are the signs and symptoms of hypothyroidism in neonate are ?
or how to diagnose neonate with hypothyroidism ?
1-birth weight and length are normal , but head size may slightly increased due to myxedema of the brain
2-prolongation of physiological jaundice caused by delayed maturation of glucuronide conjugation , and may be the earliest sign
3-feeding difficulties : especially sluggishness , lack of interest , somnolence
4-choking spells : during first month of life
5- respiratory difficulties : due to large tongue , include apneic episodes , noisy respiration , nasal obstruction, typically , respiratory distress syndrome also occurs
6- affected infants cry little sleep much have poor appetite , generally sluggish , also constipation that usually doesn't respond to treatment
7-abdomen is large and umbilical hernia is usually present
8- temperature is subnormal , often <35c
9-the skin of the extremities may be cold , mottled , also edema of genitals and hand-foot (extremities) may occur
10-the pulse slow , and heart murmurs , cardiomegaly and asymptomatic pericardial effusion are common
11- macrocytic anemia : often present and is refractory to treatment with hematinics
so conclusion : temperature may subnormal <35c , pulse slow , the baby may have large head , prolongation of physiological jaundice , poor feeding , sleep much , cry little , respiration difficulties due to large tongue , chocking speels , noisy respiration , constipation , abdomen may large , and umbilical hernia may occur , skin cold mottled of extremities , edema of genitals and extremities may occur , heart murmurs and cardiomegaly and asymptomatic pericardial effusion are common , macrocytic anemia refractory to treatment with hematinics
approximately 10% of infant with congenital hypothyroidism have associated congenital anomalies
what is the most common congenital anomalies associated with congenital hypothyroidism ?
cardiac anomalies , also anomalies of nervous system , eye
*infants with congenital hypothyroidism may have hearing loss
child growth will be stunted , extremities short , head size normal or increased , anterior and posterior fontanels are open widely , observation of this sign can serve as initial clue to early recognition of congenital hypothyroidism , the eye appear far apart , and the bridge of the broad nose is depressed , palpebral fissure are narrow and eyelids are swollen , mouth kept open , thick broad tongue protrude , dentition will be delayed , neck short and thick , deposits of fat above clavicle and between neck and shoulders , hand are broad , fingers short , skin dry , scaly , pallor , myxedema manifested particularly in skin of eyelids , back of hands , genitals , carotenemia can cause yellow discoloration of skin but the sclera remain white , scalp thickened , hair is coarse , brittle and scanty
how hypothyroidism affect the development of neonate ?
development usually delayed , baby appear lethargic ,late in learning to sit and stand , voice hoarse , dont learn talk , the degree of mental and physical retardation increase with age , sexual maturation delayed , or may not take place , muscle usually hypotonic
what is the treatment of hypothyroid neonate ?
levothyroxine is initiated in first month or less after birth , screening programs usually offer therapy in 1-2 weeks after birth .
what is the dose of levothyroxine in hypothyroid neonate ?
10-15 microgram /kg in newborn period , but 3microgram/kg used later in childhood .
what the prognosis of hypothyroid neonate ?
normal intellectual development prognosis is excellent
acquired hypothyroidism :
clinical manifestation may be subtle , hypothyroidism should suspected in any child who has decline in growth velocity , especially if not associated with weight loss .
what is the most common cause of acquired hypothyroidism in older children ?
lymphocytic autoimmune thyroiditis (hashimoto thyroiditis ) , in many area iodine deficiency is responsible for endemic goiter (endemic cretinism)
hashimoto thyroiditis :
autoimmune lymphocytic thyroiditis , common cause of goiter and acquired thyroid disease in older children and adolescent , family history of thyroid disease present in 25%-35% of patients
clinical manifestation of hastimoto thyroiditis ?
firm , non tender euthyroid , onset typically occur after 6 year of age with peak incidence in adolescence ,with female predominance .
what are the associated autoimmune diseases with hasimoto thyroiditis ?
include diabetes mellitus type 1 , adrenal insufficiency , hypoparathyroidism
how to diagnose hashimoto thyroiditis ?
confirmed by serum antithyroid peroxidase (previously antimicrosomal and antithyroglobulin antibodies )
what are the treatment of hashimoto thyroiditis ?
thyroid hormone is sufficient to normalize tsh and free T4 indicated for hypothyroidism in hashimoto thyroiditis , patient without manifestation of hypothyroidism require thyroid function test (serum TSH , T4) every 6 -12 months to detected later development of hypothyroidism , goiter with normal TSH usually is not indication for treatment
case : infant 6 months , fed poorly in neonatal period , was constipated , persistent nasal discharge and large tongue , very lethargic , no social smile and no head control , puffy face , dull expression , hirsute forehead , osseous development was that of newborn
4 month after treatment with levothyroxine , decrease in face puffiness , decrease hirsutism of forehead , and change to alert appearance
is hypothyroidism dangerous if untreated in neonate and babies ?
untreated congenital deficiency of thyroid hormone , this will result in mental retardation and stunted growth
also other varieties of hypothyroidism laboratory finding :
absence of distal femoral epiphysis in 3months old infant who was born at term , this is evidence for the onset of the hypothyroid state during fetal life
epiphyseal dysgenesis in the head of the humerus in the 9 yr old girl who had been inadequately with thyroid hormone