hypERthyroid Flashcards
primary vs secondary hyperthyroidism
primary - due to thyroid pathology
seocndary - due to pathology in hypothalamus or pituitary - producing too much TSH
Graves disease
autoimmune thyroid disease
- body produces IgG antibodies to the TSH receptor
women 30-50yrs
commonest cause of thyrotoxicosis
Graves
Graves presentation
eye signs
- exophthalmos
- ophthalmoplegia
pretibial myxoedema
thyroid acropachy, triad;
1. digital clubbing
2. soft tissue swelling of hands+feet
3. periosteal new bone formation
antibodies present in Graves
TSH receptor stimulating antibodies (90%)
anti-thyroid peroxidase antibodies (10%)
Graves investigations
autoantibodies
thyroid scintigraphy
- diffuse
- homogenous
- increased uptake of radioactive iodine
management of Graves
1st = anti-thyroid drugs - carbimazole (give if sx not controlled with propran)
propranolol = symptoms control
refer to 2nd care
carbimazole complications
! Agranulocytosis !
treatment with anti-thyroid drugs (ATD) such as carbimazole
started at 40mg, reduced gradually to maintain euthyroidism
- continued for 12-18months
when is radioiodine treatment used? what are the contraindications
in patients who relapse following ATD therapy or resistant to ATD tx
contraindications
- pregnancy - avoid 4-6mths following
- age <16
- thyroid eye disease - may worsen
amiodarone effect on thyroid
can cause both hypothyroidism + thyrotoxocosis
due to high iodine content
subclinical hyperthyroidism
normal serum free thyroxine
with LOW TSH
causes of subclinical hyperthyroidism
- multinodular goitre, esp in elderly females
- excessive thyroxine may give similar biochem picture
complications of unrecognised subclinical hyperthyroidism
effect on -
- cardiovas - atrial fibrillation
- bone metabolism - osteoporosis
increase likelihood of dementia
management of subclinical hyperthyroidism
often go back to normal - TSH levels must be persitently low to intervene
trial of low-dose antithyroid agent for 6 months to induce remission
causes of thyrotoxicosis
- graves (50-60%)
- acute phase of de Querv thyroiditis, post partum or hashimotos
- amiodarone therapy
- contrast (iodinated contrast)
–> tend to occur in elderlywith pre-exist thyroid probs
TSH + T3/4 in thyrotoxicosis
TSH down
T4/3 up
features of thyrotoxicosis
weight loss
heat intolerance
manic, restlessness
palpitations
sweating
tremor
pretibial myxoedema
pretibial myxoedema
erythematous
oedematous lesions above lateral malleoli
gynae changes in hyper vs hypo-thyroidism
hyper = oligomenorrhoea
hypo = menorrhagia
thyroid storm
rare but life threatening cx of thyrotoxicosis
- seen in patients with well established thyrotoxicosis
NOT see in iatrogenic thyroxine excess
thyroid storm precipitating events
thyroid/non-thyroid surgery
trauma
infection
acute iodine load - CT contrast
thyroid storm presentation
fever >38.5
tachycardia
confusion, agitation
N+V
hypertension
heart failure
abnormal LFTs - jaundice
mangement of thyroid storm
beta-blockers - IV propranolol
ATD - methimazole or propylthiouracil
decamethasone IV -> blocks conversion of T4-T3
