Thyrotoxicosis

The symptoms and signs of hyperthyroidism may be mild and non-specific, especially in the elderly.

Consider a diagnosis of hyperthyroidism if there are symptoms or signs of:

• Rapid-onset malaise, fever, and thyroid pain
• Compression symptoms of breathlessness, hoarse voice, dysphagia, neck pressure
• Agitation, emotional lability, insomnia, irritability, anxiety, palpitations.
• Exercise intolerance, fatigue, muscle weakness.
• Heat intolerance, increased sweating.
• Increased appetite with unintentional weight loss, diarrhoea.
• Subfertility, oligomenorrhoea, amenorrhoea.
• Agitation, fine tremor, warm moist skin, palmar erythema.
• Sinus tachycardia, atrial fibrillation, heart failure, peripheral oedema.
• Pruritus, urticaria, vitiligo, diffuse alopecia.

Examine for thyroid enlargement:

• In Graves' disease, the thyroid gland is usually diffusely symmetrically enlarged without nodules, and there may be a bruit.
• A toxic multinodular goitre typically presents with non-tender thyroid nodules.
• A toxic adenoma typically presents with a unilateral, non-tender thyroid mass.
• Subacute thyroiditis typically presents with a tender, firm, irregular, diffusely enlarged thyroid gland which may be asymmetrical.
• In amiodarone-induced thyroiditis, a small goitre is usually present.

Check blood for:

• TFTs - FT4 will automatically be added if TSH abnormal
• FBC, U&E, LFT, CRP, ESR depending on presentation

Only arrange USS neck if specific lump is identified on examination not just generalised swelling. If lump identified referral should be to General surgery rather than endocrine.

In patients presenting with new biochemical thyrotoxicosis:

• If there are significant thyrotoxic symptoms (tremor, tachycardia, feeling hot etc), beta-blockers such as Propranolol 20-40mg 2-3 times a day or 80mg modified release or 80mg Nadolol once daily (in the absence of contraindication such as asthma) may be used to help relieve symptoms- please avoid cardio-selective B-blockers such as bisoprolol as these are less effective in thyrotoxicosis
• Recheck full TFT after 1 month (requesting TSH, FT4, TT3, thyroid peridoxase and Thyrotropin antibodies)- two hyperthyroid blood tests 1 month apart are required to confirm thyrotoxicosis. Hyperthyroid results on a single sample could well be thyroiditis which is often a self-limiting condition.
• If the repeat TFTs show a worsening pattern appointment please commence:
  • Carbimazole 20-40mg once daily with the usual BNF warnings.
  • Due to the small risk of agranulocytosis, the importance of checking a full blood count in the event of significant sore throat, unexplained fever or mouth ulcers must be stressed.
  • Please check a baseline FBC and LFT when commencing Carbimazole; accepting mild neutropenia (no action other than repeat monitoring unless neutrophils less than 1.0 x10^9/l) and mild LFT derangements (no action other than repeat monitoring unless ALT >2 times upper limit of normal) can occur in a significant proportion due to hyperthyroidism itself.

Patient information leaflets can be found on the British Thyroid Foundation website (http://www.btf-thyroid.org/).

All patients with:

• new thyrotoxicosis
• recurrent thyrotoxicosis (see below)
• thyroiditis (single hyperthyroid blood result - see here)
• post-partum thyroiditis (see here)
• patients with Amiodarone induced thyrotoxicosis

should be referred to endocrinology via SCI-Gateway.

Referrals will be triaged and endocrinology aim to see most people with a new diagnosis of thyrotoxicosis around 6 weeks after the initial finding. The tests and results above will help guide the treatment plan and allow efficient use of clinic appointments.

If the patient is planning pregnancy in the near future then please let us know as it may affect our treatment recommendation.

If the patient has positive anti-TSH receptor antibodies then this would suggest Graves’ disease as the likely cause of their hyperthyroidism. A very small number of patients with Graves’ can develop thyroid eye problems. The most common complaint is dry or “gritty” eyes and lubricating drops can be used. If troublesome symptoms are experienced then our first suggestion would be to attend their local optician and mention that they are being treated for hyperthyroidism.

• If patient has previously been treated for thyrotoxicosis please commence carbimazole 20mg once daily if FT4<40 or carbimazole 40mg once daily if FT4>40
• Please prescribe the 5mg or 20mg Carbimazole tablets (rather than other available strengths which are NOT included in the Scottish Drug Tariff) as these are considerably more cost effective.
• Please check a baseline FBC and LFT when commencing (or shortly after starting) Carbimazole; accepting mild neutropenia (no action other than repeat monitoring unless neutrophils less than 1.0 x10^9/l) and mild LFT derangements (no action other than repeat monitoring unless ALT >2 times upper limit of normal) can occur in a significant proportion due to hyperthyroidism itself. Routine monitoring of FBC and LFTs is not recommended.
• Due to the small risk of agranulocytosis, the importance of checking a full blood count in the event of significant sore throat, unexplained fever or mouth ulcers must be stressed.
• If there are significant thyrotoxic symptoms (tremor, tachycardia, feeling hot etc), beta-blockers such as Propranolol 20-40mg 2-3 times a day or 80mg modified release once daily or Nadolol 80mg od (in the absence of contraindication such as asthma) may be used to help relieve symptoms. please avoid cardio-selective B-blockers such as bisoprolol as these are less effective in thyrotoxicosis
• it would be useful to recheck thyroid function tests including a free T3 in 4-6 weeks. The response to treatment will help our assessment when attending the Thyroid Clinic appointment. If the free T4 have normalised then the Carbimazole dose can be halved
• When repeating bloods, please (re)check anti TSH receptor (TRAB) antibodies The repeat anti TSH receptor antibody levels will help us in assessing the risk of subsequent recurrences.
• where possible we would encourage definitive (permanent) therapy with either radioiodine or surgery and this will be discussed at the clinic appointment

We aim to see most people with a new diagnosis of thyrotoxicosis around 6 weeks after the initial finding. The tests and results above will help guide our treatment plan and allow efficient use of clinic appointments

• Patients with subclinical hyperthyroidism with partially suppressed TSH generally don't need referral but see here
• Patients with a suppressed TSH on thyroxine (Iatrogenic subclinical hyperthyroidism)