Thyroid Disease

Question 1

When would the TBG be raised?

Answer 1

• pregnancy
• oestrogen therapy I.e. HRT, oral contraceptives
• hepatitis

Question 2

When would TBG be decreased?

Answer 2

Nephrotic syndrome
Malnutrition
Drugs- androgens, corticosteroids, phenytoin
Chronic liver disease
Acromegaly

Question 3

What are the symptoms of thyrotoxicosis? (12 common, 6 rare)

Answer 3

Diarrhoea, weight decrease, appetite increase, over-active, sweats, heat intolerance, palpitations, tremor, irritability, labile emotions, oligomenorrhea +/- infertility

Rarely, psychosis, chorea, panic, itch, alopecia, urticaria

Question 4

What are the signs of thyrotoxicosis?

Answer 4

Pulse fast/irregular (AF or SVT), warm moist skin, fine tremor, palmar erythema, thin hair, lid lag, lid retraction, goitre, thyroid nodules or bruit depending on the cause

Question 5

What are the 3 main signs of Graves’ disease?

Answer 5

1) eye disease - exophthalmos, ophthalmoplegia
2) pretibial myxoedema- oedematous swellings above lateral malleoli
3) thyroid acropachy- painful finger and toes swellings and clubbing in the hands and periosteal reaction in limb bones

Question 6

What is the cause of Graves’ disease?

Answer 6

Circulating IgG autoantibodies binding to and activating GPC thyrotropin receptors

which cause smooth thyroid enlargement

and increased hormone production

and react with orbital autoantigens.

Question 7

Name two drugs that can cause thyrotoxicosis

Answer 7

Levothyroxine excess
Amiodarone
Lithium (although more commonly causes hypothyroidism)

Question 8

Give five causes of thyrotoxicosis

Answer 8

Graves’ disease
Toxic multinodular goitre
Toxic adenoma
Ectopic thyroid tissue
Exogenous-levothyroxine, iodine excess eg food contamination, contrast media
Others - subacute de quervain’s thyroiditis, drugs (amiodarone, lithium), postpartum, TB

Question 9

What is the treatment for thyrotoxicosis?

Answer 9

Drugs

• beta blockers - propranolol 40mg/6h for rapid control of symptoms
• anti thyroid medication- 2 regimens- one with titration of carbimazole, the other called block replace uses carbimazole and thyroxine over 12-18 months

Radioiodine

Thyroidectomy

Question 10

What are the side effects of carbimazole?

Answer 10

Agranulocytosis !

Dangerous sepsis may result

Warn to stop and get urgent FBC if signs of infection eg sore throat, mouth ulcers, increase in temperature

Question 11

What are the contraindications for radioiodine?

Answer 11

Pregnancy
Lactation
Caution in active hyperthyroidism as risk of thyroid storm

Question 12

What are the risks associated with thyroidectomy?

Answer 12

Damage to recurrent laryngeal nerve
Hypoparathyroidism
Hypothyroidism

Question 13

What are the complications of thyrotoxicosis?

Answer 13

Heart failure - thyrotoxicosis cardiomyopathy
AF
angina
Osteoporosis 
Ophthalmopathy
Gynaecomastia
*thyroid storm*

Question 14

What is the pathogenesis for orbital swelling in thyroid eye disease?

Answer 14

Retroorbital inflammation and lymphocyte infiltration results in swelling of the orbit

Question 15

What are the signs of thyroid eye disease?

Answer 15

Exophthalmos
Proptosis- eyes protrude beyond the orbit
Conjunctival oedema
Corneal ulceration
Papilloedema
Loss of colour vision
Opthalmoplegia occurs due to muscle swelling and fibrosis

Question 16

What are the causes of goitre? 5 diffuse, 3 nodular

Answer 16

Diffuse- physiological, Graves’ disease, Hashimoto’s thyroiditis, de quervains subacute thyroiditis (painful)

Nodular- multinodulr goitre, adenoma, carcinoma

Question 17

Signs and symptoms of thyrotoxic storm

Answer 17

Increases temperature
Agitation
Confusion
Coma
Tachycardia
AF
Diarrhoea and vomiting
Goitre
Thyroid bruit
Acute abdomen
Heart failure
Cardiovascular collapse

Question 18

What are the symptoms of hypothyroidism?

Answer 18

Tired, sleepy, lethargic,
Mood low, 
Cold disliking
Weight gain
Constipation
Menorrhagia
Hoarse voice
Decreased memory/cognition
Dementia
Myalgia
Cramps
Weakness

Question 19

What are the signs of hypothyroidism?

Answer 19

Bradycardia
Reflexes relax slowly
Ataxia
Defeated demeanour
Yawning/coma/drowsy
Cold hands +/- low temp
Ascites +/- non pitting oedema of legs, hands, feet +/- pericardial or pleural effusion
Round puffy face/ double chin/ obese
Dry thin skin, hair
Ileus/ immobile
CCF

Question 20

What are the causes of primary autoimmune hypothyroidism?

Answer 20

Primary atrophic hypothyroidism- NO goitre due to diffuse infiltration of lymphocytes infiltrating the thyroid leading to atrophy
Hashimoto’s thyroiditis- goitre due to lymphocyte and plasma cell infiltration

Question 21

What are four non autoimmune causes of primary hypothyroidism?

Answer 21

1) iodine deficiency
2) thyroidectomy or radioiodine treatment
3) drug induced- anti thyroid drugs, amiodarone, lithium, iodine
4) subacute thyroiditis

Question 22

What is poems syndrome?

Answer 22

Polyneuropathy
Organomegaly
Endocrinopathy
M- protein band (plasmacytoma)/ myeloma protein
Skin pigmentation/tethering

Other signs/symptoms= PEST stands for Papilledema, evidence of Extravascular volume overload (ascites, pleural effusion, pericardial effusion, and lower extremity edema), Sclerotic bone lesions, and Thrombocytosis/erythrocytosis (i.e. increased in blood platelets and red blood cells).

Question 23

Name a genetic condition which results in hypothyroidism

Answer 23

Dyshormonogenesis

Pendred’s syndrome

Question 24

What are four common causes of primary hypothyroidism

Answer 24

primary hypothyroidism with a high TSH and low T4. The common causes are:
Autoimmune (Hashimoto’s disease, atrophic)
Iodine deficiency
Thyroiditis (post-viral, post-partum)
Iatrogenic (thyroidectomy, radioiodine, drugs)

Question 25

What would you see with TSH and T4 levels in secondary hypothyroidism

Answer 25

Low TSH and Low T4

In these cases pituitary insufficiency is most likely therefore an MRI of the gland should be performed

Question 26

Side effects of levothyroxine

Answer 26

○ hyperthyroidism: due to over treatment
○ reduced bone mineral density
○ worsening of angina
○ atrial fibrillation