Endocrinology Flashcards
What is an endocrine sign we might see as dentists?
Enlarged thyroid gland
What are some endocrine causes of an abnormally large tongue?
Hypothyroidism, amyloidosis, lymphoma
Which hormones are produced in the adrenal medulla?
Adrenaline and noradrenaline
Which hormones are produced in the adrenal cortex?
Mineralocorticoids, glucocorticoids, androgens
What is primary adrenal insufficiency?
Addison’s disease
Problem with adrenal gland itself, High ACTH
What is secondary adrenal insufficiency?
Decreased pituitary ACTH production
Due to problem eg tumour in the pituitary gland
What is tertiary adrenal insufficiency?
Glucocorticoid withdrawal (tablets, creams, inhalers, injections)
What happens to ACTH levels in someone with adrenal insufficiency due to adrenal cause?
High ACTH
What causes unusual pigmentation in Addison’s disease?
High levels of ACTH - ACTH is structurally similar to melanocyte stimulating hormone and so can act on melanocytes causing pigmentation
Which type of adrenal insufficiency may be associated with abnormal pigmentation?
Primary / Addison’s disease
What test can be used to diagnose adrenal insufficiency?
Short synacthen test
What is the short synacthen test?
Tests for adrenal insufficiency by giving a synthetic injection of ACTH. A normal response would be to increase cortisol production
Note that this test stimulates the adrenal glands directly and not the hypothalamus pituitary axis
What does the pituitary foundation recommend for tooth extractions?
20mg hydrocortisone or double the usual amount of prednisolone prior to tooth extractions
What does the Addison’s disease self-help group suggest for dental procedures?
Check up or cleaning - no extra hydrocortisone
Planned LA - double or triple hydrocortisone dose 24h before; Unplanned LA - double or triple dose asap and continue for 24h
How should a person with adrenal insufficiency manage their condition if they feel unwell?
Double up steroid dose
Take 100mg IM hydrocortisone if can’t take the tablets or are vomiting
What is Cushing’s syndrome?
Excess cortisol
Manifestations of Cushing’s syndrome?
Easy bruising, round moon face, red/purple striae, muscle weakness in arms and legs, osteoporosis, obesity, emotional disturbance
What is facial plethora?
Swelling, puffiness and redness of the face
Can be a sign of Cushing’s disease
Causes of Cushing’s Syndrome?
Steroid therapy, ACTH dependent eg ectopic ACTH secretion, ACTH independent eg adrenal adenoma or adrenal carcinoma
What conditions are associated with hypercortisolism in the absence of Cushing’s syndrome?
Pregnancy, depression and other psychiatric conditions, alcohol dependence, morbid obesity
What are the two biologically active thyroid hormones?
Thyroxine (T4) and triiodothyronine (T3)
What is a key ingredient for the synthesis of thyroid hormones?
Iodine
How is T4 converted to T3?
Deiodinases
What are normal TSH levels?
0.35 to 4.5
What are normal free T3 levels?
3-7
What are normal T4 levels?
10-25
What is levothyroxine?
Synthetic T4
What can be used to treat primary hypothyroidism?
Levothyroxine
Which gender is most affected by hypothyroidism?
Female
Main causes of hypothyroidism?
Atrophic autoimmune thyroiditis, Hashimoto’s thyroiditis, post treatment for thyrotoxicosis
What is Graves’ disease?
Overactive thyroid - increased levels of T3 and T4
Associated with antibodies
What are the two most common causes of overactive thyroid?
Graves’ disease, toxic multi-nodular goitre
Signs of Graves’ disease?
Smoothly enlarged goitre, protrusion of the eyes
Treatment for thyrotoxicosis?
Tablets - carbimazole, PTU; radioactive iodine; surgery
Risk of thyroid surgery?
Recurrent laryngeal nerve injury -> damage to voice, damage to parathyroid glands (low calcium levels)
Differential diagnosis of a thyroid swelling?
Multinodular goitre with a dominant nodule, thyroid cyst, thyroid cancer
What is acromegaly?
Excess growth hormone after long bone closure
Signs of acromegaly?
Spaced teeth, enlarged facial features, thicker bones
What is gigantism?
Hypersecretion of GH in children (before closure of long bones)
What are some complications of acromegaly?
Visual field defects, headaches, diabetes, decreased libido, sleep apnoea, hypertension, cardiomyopathy, arthritis, carpal tunnel syndrome
What would be increased in acromegaly?
IGF1
What is the oral glucose tolerance test?
Test for diabetes that can also be used for acromegaly
For diagnosing acromegaly, how often should blood be taken during the oral glucose tolerance test?
0 mins, every 30 mins up to 150 mins
GH fails to suppress
Treatment options for acromegaly?
Surgery to remove tumour, somatostatins, GH inhibition
