clinical thyroid disease 2 Flashcards
what is the difference between subclinical hyperthyroidism and compensated hyperthyroisism?
describe thyroid hormone secretion in hyperthyroidism?
what are primary causes of thyrotoxicosis?
Grave’s disease (70%)
Toxic Multinodular Goitre (20%)
Toxic adenoma
what are secondary causes of thyrotoxicosis?
Pituitary adenoma secreting TSH
Thyrotoxicosis without hyperthyroidism
Destructive thyroiditis (post-partum, subacute [de Quervain’s], amiodarone-induced
Excessive thyroxine administration
what is the incidence and prevalence of graves disease?
70-80% of all cases of hyperthyroidism
Incidence 2-3 per 1000 per year (Sex ratio 5:1)
Prevalence 1.9% female, 0.16% male
what is graves disease
Autoimmune driven condition
thyroid peroxidase Antibodies
TSH receptor Antibodies
review personal/family history for concurrent autoimmune disease
how is graves disease diagnosed?
Hyperthyroidism
Thyroid antibodies
(TSH Receptor antibodies)
thyroid eye disease, odema, goitre, clubbing, gynomastica
what is multi-nodula goitre?
Most common cause of thyrotoxicosis in the elderly
Characteristic goitre and absence of Grave’s disease
Will not go into spontaneous remission
what is subacutre (de quervains) thyroiditis?
Generally younger patients <50 years
Viral trigger (eg enteroviruses, coxsackie)
Often recall painful goitre +/- fever/myalgia; ESR increase
May require short term steroids and NSAIDs
how can hyperthyroidism be treated?
radioactive iodine
surgery
antithyroid drugs - holding measure wont cure
beta blockers - reduce peipheral manifestations >(tremors, tachycardia)
what are examples of antithyroid drugs?
what is a common side effect of carbimaxzole?
rash
what are side effects of propylthiouracil?
hepatotoxicity, ussually reserved for pregancy or short term use
what are different regimines for antithyroid drugs?
block and replace - use high dose and maintain high dose, once patient euthyroid replace wuth thyroxin
titration regime - start high dose and reduce as things get better and maintin low dose for around 18 months
what is the most common treatment plasn of antithyroid drugs?
ATD often on 1st occasion (40% chance of being cured and off medication).
Usually titration regimen, 12-18 months
Selected cases for long term low dose ATD
Elderly
Cardiac complications
Unwilling for RAI
what is radioiodine?
has to be given with precautions as with stay in thyroid gland for 3 to 4 weeks
Patients usually choose ATD before RAI
Treat with ATD (stop 4-7 days before and after)
Elderly, Risk of cardiac problems
Usually given as high / ablative dose
70% risk of hypothyroidism
Avoided in severe eye disease
38 year old woman
Graves Hyperthyroidism recurrence
TSH <0.02. FT4: 70 (N:10-25), Ft3: 25 (N:3-7)
TRAB: 18 (N: <1.5)
recommended
Carbimazole
Radioiodine - young children so chose surgery
subclinical hyperthyroidism summary?
TSH suppressed
Normal Free thyroid hormones
Concerns:
Bone: decreased bone density in postmenopausal; No clear fracture data
AF: 3 fold increased risk in over 60s
Treatment considered ATD/RAI if persistent especially in elderly or those with increased cardiac risk
56 year old man
Tiredness and low energy
Funny TFTs
TSH: 2.84 (0.55-4.78mU/l)
FT4: 9 (10-25pmol/l)
Seen in Endocrine, Reduced libido for 4 years
LH<1, FSH 2.1, Testosterone <0.2
Peak cortisol on SST: 368nmol/l (N: >500)
Started Hydrocortisone first
Then Levothyroxine
secondary bhyperthyroidism
