Thyroid Flashcards
Thyrotoxicosis definition
Clinical effect of ↑T4
Usually from gland hyperfunction
Sx of thyrotoxicosis
- Diarrhoea
- ↑ appetite but ↓ wt.
- Sweats, heat intolerance
- Palpitations
- Tremor
- Irritability
- Oligomenorrhoea ± infertility
Signs of thyrotoxicosis in the hands
- Fast / irregular pulse
- Warm, moist skin
- Fine tremor
- Palmer erythema
Signs of thyrotoxicosis in the face
- thin hair
- lid lag
- lid retraction
Signs of thyrotoxicosis in the neck
goitre or nodules
Signs specific to Graves
- Exophthalmos
- Pre-tibial myxoedema
- Thyroid acropachy
Thyroid acropachy definition
Clubbin and swelling of digits
Ix for thyrotoxicosis
High T4
Low TSH
Autoantibodies
Most common cause of thyrotoxicosis?
Graves’ disease
Triggers of Graves disease
- stress
- infection
- child-birth
Conditions associated to Graves disease
T1DM
Vitiligo
Addison’s
Other causes of thyrotoxicosis
Toxic multinodular goitre
Toxic adenoma
Thyrotoxic phase of thyroiditis
Drugs
Drugs causing thyrotoxicosis
Thyroxine
Amiodarone
Medical treatment for thyrotoxicosis
Beta blocker - sx relief
Carbimazole
Action of carbimazole
Anti-thyroid
Inhibits TPO
Use of carbimazole in Graves’ disease
Rx 12-18 mo
Then withdraw
~ 50% relapse (→ surgery or radioiodine)
SE of carbimazole
Agranulocytosis
Radiological treatment for thyrotoxicosis
CI
Radioactive iodine
CI in pregnancy
Surgical treatment for thyrotoxicosis
Thyroidectomy
Thyroid storm definition
Thyrotoxic crisis
Acute life-threatening hypermetabolic state
Induced by excessive release of thyroid hormones
Features of thyroid storm
- ↑ temp
- Agitation, confusion, coma
- Tachycardia, AF
- Acute abdomen
- Heart failure
Precipitants to thyroid storm
Recent thyroid surgery
Radioactive iodine
Infection
MI
Trauma
Mx of thyroid storm
- Fluid resuscitation + NGT
- Bloods: TFTs + cultures
- Propranolol
- Digoxin may be needed
- Carbimazole
- Hydrocortisone
- Rx cause
Sx of hypothyroidism
- Lethargy
- Cold intolerance
- ↓ appetite but ↑wt.
- Constipation
- Menorrhagia
- ↓ mood
Signs of hypothyroidism
- Cold hands
- Bradycardic
- Slow-relaxing reflexes
- Dry hair and skin
- Goitre
- Myxoedema
Myxoedema definition
- SC tissue swelling in severe hypothyroidism
- Typically around eyes and dorsum of hand
Causes of hypothyroidism
- Atrophic thyroiditis
- Hashimoto’s thyroiditis
- Post De Quervain’s thyroiditis
- Iodine deficiency
- Drugs
- Congenital thyroid agenesis
- Hypopituitarism
Drugs causing hypothyroidism
Carbimazole
Amiodarone
Lithium
Most common cause of hypothyroidism in UK
Atrophic thyroiditis
Most common couse of hypothyroidism worldwide
Iodine deficiency
Ix for atrophic thyroiditis
Anti-TSH antibody positive
Features of atrophic thyroiditis
Lymphocytic infiltrate → atrophy
No goitre
Ix for Hashimoto’s thyroiditis
TPO positive
(Thyroid peroxidase antibody)
Features of Hashimoto’s thyroiditis
- Atrophy + regeneration → goitre
- May go through initial thyrotoxicosis phase
- May be euthyroid or hypothyoid
Ix for hypothyroidism
High MCV
High TSH
Low T4
Antibodies
Mx of hypothyroidism
Levothyroxine
Follow up for other autoimmune diseases
Features of myxoedema coma
- Looks hypothyroid
- Hypothermia
- Hypoglycaemia
- Heart failure: bradycardia and ↓BP
- Coma and seizures
Precipitants to myxoedema coma
- Radioiodine
- Thyroidectomy
- Pituitary surgery
- Infection, trauma, MI, stroke
Mx of myxoedema coma
Bloods
Correct any hypoglycaemia
T3/T4 IV slowly
Hydrocortisone
Rx hypothermia and heart failure
Why give T3/T4 slowly in myxoedema coma?
May precipitate MI
