Endocrinology Flashcards
A patient has a large goitre with possibly some nodules, how should it be investigated?
TFTs
Ultrasound (cystic or solid? Aka typically benign or malignant)
Fine needle aspiration
Consider a radioiodine isotope scan to determine cause of hyperthyroidism- absent isotope uptake suggests inflammation or destroyed tissue
Which diseases put patients at risk of thyroid disease?
Hyperlipidaemia Diabetes mellitus Those on amiodarone (arrhythmia) or lithium (bipolar) Down's or Turner's Addison's
Signs of thyrotoxicosis not specific to Graves:
Underdressed for temperature Warm moist skin Fine tremor Palmar erythema Thin hair Lid lag- eyelids lag behind the eye's descent Lid retraction
3 Signs of Grave’s disease specifically:
1 Eye: opthalmaplegia, proptosis (exopthalmus is Grave’s is cause)
2 Pretibial myxoedema
3 Thyroid acropachy- clubbing, painful fingers and toes (Extreme manifestation)
Cause of Grave’s disease:
Circulating IgG autoantibodies that activate G-protein coupled thyrotropin) receptors
= smooth thyroid enlargement and increased hormone production
Causes of thyrotoxicosis:
Graves’ (2/3rds)
Toxic multinodular goitre (related to gene mutations, nodules secrete hormones)
Toxic adenoma (solitary nodule producing T4/3, rest of gland is supressed)
Ectopic thyroid tissue- metastatic follicular cancer
Exogenous- iodine excess, levothyroxine
Subacute De Quervain’s Thyroditis- postviral self limiting
How can you try to differentiate between Graves and multinodular goitre or toxic adenoma on palpation of the gland?
Graves- smooth diffuse enlargement
Toxic adenoma or multinodular goitre- more palpable nodules
Other nodular:
Carcinoma
Other diffuse enlargement:
Hashimoto’s, subacute De Quervain’s
Drug treatment of thyrotoxicosis:
- Propranolol
- Carbimazole (agranulocytosis SE) ± levothyroxine
Inhibits the thyroid peroxidase enzyme iodinating the hormones
Risk of thyroidectomy? (Things to look for if someone has a thyroid placed scar)
Recurrent laryngeal nerve damage- hoarse voice
Hypoparathyroidism- tingling, burning sensation, muscle cramps
In which diseases might anti-thyroid peroxidase antibodies be present?
Graves disease
Or Hashimoto’s (chronic autoimmune hypothyroidism)
Signs of Graves eye disease:
I- Exopthalmus- appearance of protruding eye
Proptosis- eyes protrude beyond the orbit
Conjunctival oedema
Corneal ulceration
F- Papilloedema
A- Loss of colour plates
CNIII- opthalmaplegia from muscle swelling and fibrosis restricting movement
How is Graves eye disease treated?
Caused by lymphocyte infiltration and periorbital swelling:
Mild- symptomatic (artificial tears, sunglasses, avoid dust, elevate head at night, prisms on glasses for diplopia)
Severe- with opthalmaplegia or gross oedema:
IV methylprednisolone
Surgical decompression
What are the symptoms of hypothyroidism:
BRADYCARDIC
Bradycardia Reflexes relaxing slowly Ataxia (cerebellar) Dry skin/hair Yawning/drowsy Cold hands + low T Ascites ± non-pitting oedema ± pleural/pericardial effusion Round puffy face Defeated demeanor Immobile CCF
Neuropathy, myopathy
Causes of primary hypothyroidism:
Autoimmune- atrophic or Hashimoto’s (lymphocytic)
Iodine deficiency
Iatrogenic- thyroidectomy, radioiodine therapy, amiodarone, lithium
Subacute De Quervain’s- postviral (temporary)
What does POEMS syndrome stand for:
Polyneuropathy Organomegaly Endocrinopathy M-protein band (plasmacytoma) Skin tethering/pigmentation
How can amiodarone cause thyrotoxicosis and why may thyroid problems persist once stopped?
Has a cytotoxic effect on thyroid follicular cells, may cause a thyroiditis causing thyroid release
Amiodarone has a half life of 80 days
What effect does excess cortisol have?
In excess, it acts like aldosterone
Salt retention at the expense of H+ and K+
= hypokalaemic hypertensive alkalosis
Ie in Cushing’s, adrenal hyperplasia, ectopic ACTH
Patient has the signs of Grave’s disease but is euthyroid, what could the cause be?
Could still be Graves, before thyroid disease has occurred yet
There are TSH-receptors in the eye
Rx for grave’s
Carbimazole
Propylthiouracil
SE: agranulocytosis- rash, fever, sore throat
Features of MEN1?
Pituitary tumours
Pancreatic neuroendocrine tumours (VIPoma)
Parathyroid tumours- all 4 glands may be affected
What test can determine whether a patient has high Ca2+ because of a familial kidney condition?
Urine calcium should be low if they have benign hypocalciuric hypercalcaemia
Secondary causes of diabetes:
Drugs: steroids, thiazides, atypical antipsychotics (olanzepine)
PMH: CF, chronic pancreatitis, haemochromotosis, Cushing’s/phaeochromocytoma, acromegaly
MODY, gestational, DIDMOAD
Patient has random glucose of 10, what would your next line of investigation be?
Between 7-11 do a fasting glucose test
If fasting glucose is >7 do an oral glucose tolerance test
+ve if above 11
How long do you fast for before taking a fasting blood glucose?
8 hours