Thyroid

Question 0

TSH up

fT4 N

Answer 0

Subclinical Hypothyroidism:
Txt: ​Screen for Anti-TPO antibodies
​In pregnancy; increased risk of miscarriage, preterm labour
Txt if TSH >10mu/L, other organ-specific autoimmunity (DM1, myasthenia, pernicious anaemia, vitiligo), hyperlipidemia (non-responsive to other txts)

Question 1

TSH up

fT4 down

Answer 1

1o Hypothyroidism:

Txt: thyroixine, up thyroxine in pregnancy ~30%

Question 2

TSH up/N

fT4 down

Answer 2

2o Hypothyroidism:
Txt: Thyroxine, but use fT4 to monitor pt not TSH
* Always ensure cortisol axis is working properly or you could precipitate an adrenal crisis *

Question 3

TSH down

fT4 up

Answer 3

1o Hyperthyroidism:
Graves Disease – Anti-TSHreceptor antibodies
Thyroiditis, painful goitre (cold) (β-blocker)
Use iodine uptake scan
Toxic multinodular goitre, F, 50’s (RAI 1st line)
Toxic Nodule (RAI 1st line)
Biopsy cold nodules for malignany
Med causes amiodarone (stop amiodarone /Carbimazole /PTU /steroids /thyroidectomy NB T½=80 days), lithium

Txt: ​β-blockers (symptom control)
​Carbimazole (can cause agranulocytosis)
​Propylthiourasol PTU (Rare, risk of liver failure)
Radioactive iodine (avoid pregnant women and small children for 2 weeks post-RAI, cannot get pregnant for 6 months post-RAI, most go Hypothyroid post-RAI, some euthyroid)
Surgery (All hypothyroid post-op)

Question 4

TSH down

fT4 N

Answer 4

Subclinical Hyperthyroidism:

Txt: if TSH <0.1mu/L (at risk of A. fib, osteoporosis)

Question 5

TSH up/N

fT4 up

Answer 5

2o Hyperthyroidism:
Causes: 1. Pituitary adenoma
​ 2. β-receptor thyroid hormone RTH, autosomal dominant
(α-receptors in cardiac & bone, β-receptor in pituitary)

Question 6

Hypothyroidism clinical features

Answer 6

• Gruff voice, slow cerebration (mental processing)
• Coarse facial features
• Dry, cold, scaly skin
• Slow pulse and slow relaxation biceps jerk
• May have goitre (Hashimoto’s disease)
• May have myxoedema (soft tissue swelling)

Question 7

Graves’ disease triad

Answer 7

Goitre, eye signs, thyrotoxicosis

Question 8

Graves eye disease

Answer 8

• Oedema (periorbital and chemosis – swelling around conjunctiva)
• Proptosis
• Retraction (autonomically mediated)
• Exposure keratopathy
• Ophthalmoplegia (upgaze palsy)

Question 9

Peripheral thyroid status

Answer 9

• Lid retraction and/or lid lag
• Clubbing and onycholysis
• Fine tremor, moist palms
• Tachycardia, atrial fibrillation
• Biceps reflex
• Slow relaxation – hypothyroid
• Proximal myopathy
• Pre-tibial myxoedema
• Thyroid dermopathy (non-pitting)