Thursday, May 28, 2009

Hypothyroidism

Kris Hendricks, LMC/St. Joseph Hospital
Literature Review

Hypothyroidism Facts Sheet

Primary
  • 95% of cases
  • Congenital hypothryoidism
  • Thyroid agenesis
  • Dysplasia
  • Cretenism affects 1 in 3500 newborns

Acquired primary hypothryoidism
  • Hashimoto thyroiditis autoimmune disease--most common cause after age 8
  • Teratogenic drug induced
  • Iodine deficiency: very common in developing countries
  • Radiation destruction
  • Surgical removal
  • Idiopathic

Secondary
  • 5% of cases
  • Pituitary or hypothalmic dysfunction
  • congenital hypopituitarism
  • Pituitary necrosis


Course of disease
  • Generalized reduction in metabolic function, most often manifested as slowed physical and mental activity
  • In very young infants, it can cause irreversible mental retardation and slowed physical growth
Prognosis
good, with very early treatment, but 3 of 4 infants with hypothyroidism will have lower IQ later in life despite early treatment.

Complications
  • myxedema coma, mental dysfunction, stupor, cardiovascular collagse
  • anemia, dilutional hyponatremia, hyperlipidemia
  • impact on growth and development affecting CNS, skeletal, GI, repoductive, etc. 

Diagnosis:
  • Good med hx and assay of TSH and free T4 levels. 
  • Congenital usually first found in neonatal screenings, but lab errors--or lack of neonatal screenings could lead to later diagnosis relying on clinical signs. 
  • Acquired is usually presents with growth deceleration first or maybe goiter

Treatment:
  • Depends on underlying cause
  • Replacement thyroxine (levothyroxine), orally

Oral Findings:
  • enlarged tongue
  • delayed dental development and eruption
  • malocclusion
  • gingival edema
  • delayed skeletal development
  • protruding tongue and thick lips

Dental management:
  • Good medical history
  • sensitivity to stress, infection, surgery
  • sensitivity to some drugs like sedatives and opioid analgesics
  • myxedema coma signs include hypothermia, bradycardia, hypotension, seizures
  • consult with physician

No comments:

Post a Comment