Thyroid Disease Flashcards
When would the TBG be raised?
- pregnancy
- oestrogen therapy I.e. HRT, oral contraceptives
- hepatitis
When would TBG be decreased?
Nephrotic syndrome Malnutrition Drugs- androgens, corticosteroids, phenytoin Chronic liver disease Acromegaly
What are the symptoms of thyrotoxicosis? (12 common, 6 rare)
Diarrhoea, weight decrease, appetite increase, over-active, sweats, heat intolerance, palpitations, tremor, irritability, labile emotions, oligomenorrhea +/- infertility
Rarely, psychosis, chorea, panic, itch, alopecia, urticaria
What are the signs of thyrotoxicosis?
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
What are the 3 main signs of Graves’ disease?
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
What is the cause of Graves’ disease?
Circulating IgG autoantibodies binding to and activating GPC thyrotropin receptors
which cause smooth thyroid enlargement
and increased hormone production
and react with orbital autoantigens.
Name two drugs that can cause thyrotoxicosis
Levothyroxine excess
Amiodarone
Lithium (although more commonly causes hypothyroidism)
Give five causes of thyrotoxicosis
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
What is the treatment for thyrotoxicosis?
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
What are the side effects of carbimazole?
Agranulocytosis !
Dangerous sepsis may result
Warn to stop and get urgent FBC if signs of infection eg sore throat, mouth ulcers, increase in temperature
What are the contraindications for radioiodine?
Pregnancy
Lactation
Caution in active hyperthyroidism as risk of thyroid storm
What are the risks associated with thyroidectomy?
Damage to recurrent laryngeal nerve
Hypoparathyroidism
Hypothyroidism
What are the complications of thyrotoxicosis?
Heart failure - thyrotoxicosis cardiomyopathy AF angina Osteoporosis Ophthalmopathy Gynaecomastia *thyroid storm*
What is the pathogenesis for orbital swelling in thyroid eye disease?
Retroorbital inflammation and lymphocyte infiltration results in swelling of the orbit
What are the signs of thyroid eye disease?
Exophthalmos
Proptosis- eyes protrude beyond the orbit
Conjunctival oedema
Corneal ulceration
Papilloedema
Loss of colour vision
Opthalmoplegia occurs due to muscle swelling and fibrosis
What are the causes of goitre? 5 diffuse, 3 nodular
Diffuse- physiological, Graves’ disease, Hashimoto’s thyroiditis, de quervains subacute thyroiditis (painful)
Nodular- multinodulr goitre, adenoma, carcinoma
Signs and symptoms of thyrotoxic storm
Increases temperature Agitation Confusion Coma Tachycardia AF Diarrhoea and vomiting Goitre Thyroid bruit Acute abdomen Heart failure Cardiovascular collapse
What are the symptoms of hypothyroidism?
Tired, sleepy, lethargic, Mood low, Cold disliking Weight gain Constipation Menorrhagia Hoarse voice Decreased memory/cognition Dementia Myalgia Cramps Weakness
What are the signs of hypothyroidism?
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
What are the causes of primary autoimmune hypothyroidism?
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
What are four non autoimmune causes of primary hypothyroidism?
1) iodine deficiency
2) thyroidectomy or radioiodine treatment
3) drug induced- anti thyroid drugs, amiodarone, lithium, iodine
4) subacute thyroiditis
What is poems syndrome?
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).
Name a genetic condition which results in hypothyroidism
Dyshormonogenesis
Pendred’s syndrome
What are four common causes of primary hypothyroidism
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)
