Thyroid disease

Station 2 or Station 5:

"This lady has been presented with...

  • Puffy / swollen eyes

  • Neck lump

  • Sweating / Palpitations / Anxiety / Tremor" 

    • (in other words - symptomatic thyrotoxicity)​

History-taking:​

Thyroid eye disease:

  • Visual loss or reduction in visual acuity

  • Eye pain, redness & swelling

  • Diplopia (double vision) - may be in pattern of complex ophthalmoplegia

  • Difficulty closing their eyes, when severe can lead to exposure keratitis in severe cases

Red flag symptoms warrant an urgent, same day assessment by ophthalmology:

  • Diplopia / complex ophthalmoplegia

  • Significant visual loss

  • Red desaturation – suggestive of optic neuritis

Neck lump:

  • Duration: chronic goitres tend to be benign, does not mean they don’t need treatment!

  • Size – has the lump changed in size since it was first noticed?

    • Malignant thyroid nodules tend to grow faster

  • Compressive symptoms: 

    • Difficulty swallowing or speaking

Symptomatic thyroid disease:

  • Patients will volunteer their most obvious presenting symptom
  • Ask about most common presenting symptoms as per the table below:

Key tip

With limited time in PACES, assessing thyroid status thoroughly is challenging

 

Have a systematic approach for thyroid assessment so you can quickly and fluently assess thyroid status

Consider: 

  • ‘Top to toe’ approach

  • Systems-based approach – cardiovascular, respiratory, gastrointestinal etc.

Examination

Thyroid eye disease

Inspection from front, side and above

  • Exophthalmos

  • Lid retraction

  • Lid lag on rapid downward gaze

  • Assess eye movements for ophthalmoplegia

    • Look for diplopia not in keeping with an isolated cranial nerve pathology e.g. CN III palsy

  • Assessment of visual acuity

    • Offer to use a Snellen chart 

Neck lump

 

Inspection

  • For goitre or thyroidectomy scar

 

Palpation

  • From behind for goitre, size, shape, tenderness 

  • Swallow assessment

  • Regional lymph node examination

Auscultate

  • For bruits – these occur due to increased blood flow to an enlarged, overactive thyroid in thyrotoxicosis patients, but are rare in clinical practice

Thyroid status examination

 

  • Hands

    • Warm & sweaty

    • Fine tremor

    • Cold, dry skin

    • Thyroid acropachy (sometimes known as pseudo-clubbing)

  • Pulse

    • Heart rate or AF

  • Legs

    • Proximal myopathy (more often hyperthyroidism but difficult to differentiate from general fatigue from hypothyroidism)

    • Delayed deep tendon reflexes (hypo) 

    • Pretibial myxoedema (hypo

Key tip

Patients who have had a thyroidectomy are perfect for PACES.

Don't forget that even if a patient has had a thyroidectomy in the past, often residual tissue may be left or not excised at the time of surgery.

This remaining tissue can be the source of recurrent symptoms, so don't discount thyroid disease purely on the basis of a thyroidectomy in their past medical history

Investigations

  • Thyroid function tests (TFTs)

    • Thyrotoxicosis – low TSH, high T3/T4

    • Hypothyroidism – high TSH, low T3/T4

    • Subclinical hypothyroidism – high TSH, normal T3 and T4

    • Subclinical hyperthyroidism – low TSH, normal T3 and T4

Subclinical hyperthyroidism is associated with an increased risk of developing atrial fibrillation and osteoporosis, and still warrants treatment. 

  • TSH receptor antibodies (TRABs)

    • Positive in Graves’ disease

    • Can help to differentiate between Graves’ cisease and toxic multinodular goitre.

 

Management 

Thyroid eye disease

  • Supportive management

    • Topical lubricants for patients at risk of exposure keratitis

    • Selenium may improve thyroid eye disease

  • Medical management

    • High dose prednisolone (60mg) for thyroid eye disease

      • Can be started same-day in severe cases whilst awaiting urgent ophthalmology assessment

    • Immunotherapies e.g. rituximab

  • Specialist / surgical management 

    • Orbital radiotherapy

    • Orbital decompression surgery – often a ‘last resort’ however may be performed urgently if there are any sight-threatening features

Hyperthyroidism

  • Symptomatic treatment with propranolol 

    • Weaned as symptoms improve

    • Helps to decrease conversion to T4 peripherally

  • Definitive treatment: Carbimazole or Propylthiouracil

    • Titration regime – High dose carbimazole or propylthiouracil is titrated to thyroid response

    • ‘Block + replace’ regime – the patient is given high dose carbimazole alongside thyroxine

  • Patient counselling:

    • Carbimazole is relatively contraindicated in women of childbearing age, pregnancy or breastfeeding, therefore propylthiouracil is preferred

    • Risk of agranulocytosis with carbimazole. Patients should be advised to seek medical attention if they develop a severe sore throat

 

Graves disease

  • Approximately 33% of Graves’ Disease patients will only need one course of treatment

  • Relapses occur in 66% and are treated with radioactive iodine or surgical thyroidectomy

 

Toxic multinodular goitre:

  • Radioactive iodine

    • Radioactive iodine is taken up by the toxic nodules whilst the rest of the thyroid maintains normal function

    • Patients are required to isolate for two weeks post-treatment

    • Contraindicated in thyroid eye disease

Hypothyroidism

  • Levothyroxine supplementation

    • Check lipid levels: cholesterol may be raised in hypothyroidism.

      • This often resolves once levothyroxine is started and thyroid function is optimised

      • Hypercholesterolaemia only requires treatment if lipids remain high after TFTs normalise

  • Patient counselling

    • Levothyroxine should be taken on an empty stomach, half an hour before food. This is due to its interaction with calcium (reduces absorption of levothyroxine). A common reason for persistence of symptoms despite levothyroxine therapy is concurrent use of a calcium supplement

Common examiner questions

What are the possible causes of thyrotoxicosis?

  1. Graves’ Disease (autoimmune)

  2. Toxic multinodular goitre

  3. Single thyroid adenoma

  4. Thyroiditis (post-partum, post-viral illness)

  5. Drugs – amiodarone, lithium, over-the-counter drugs (seaweed/iodine)

 

What are the differential diagnoses for a thyroid neck lump?

  • Thyroid cancer – neck lump will usually grow faster, and may have malignant symptoms like fatigue, unintentional weight loss and night sweats, along with difficulty swallowing, a persistent sore throat and pain in the front of the neck.

    • Often not associated with systemic symptoms of thyrotoxicosis or hypothyroidism.

  • Multinodular goitre

  • Thyroid adenoma

  • Single nodule