Thyroid Disease Thyroid

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Thyroid Disease Thyroid Powered By Docstoc
					Thyroid disease

  Nazif Perwez
    Joy Coles
 GPST2 - Oct 2010
Primary Hyperthyroidism
90% of cases are due to:
 Grave's disease
 toxic nodular goitre:
    multinodular
    single toxic nodule - usually an adenoma

Other common causes:
 thyroiditis
    de Quervain's
    silent / post-partum
    Hashimoto's - hashitoxicosis may develop mid-course

Uncommon:
 intentional / factitious
 overenthusiastic therapy
 drug-induced
 Jod - Basedow
 transient - neonatal
Secondary Hyperthyroidism
 Hyperthyroidism as a result of pathology in another organ
  which causes excess stimulation of the thyroid gland.

Excess TSH:

 uncommon:
    TSH secreting pituitary adenoma
    pituitary stimulation due to excessive hypothalamic release of
      TRH

 rare:
    hydatidiform moles
    choriocarcinoma
    embryonal testicular carcinoma

 Extraneous thyroid hormone - all rare:
 struma ovarii - ovarian teratoma with thyroid tissue
 metastatic, well differentiated thyroid carcinoma
       Differential Diagnoses

 anxiety states:
    differentiation may be difficult clinically
    positive findings for thyrotoxicosis are eye signs,
     proximal myopathy, wasting, hyperdynamic circulation
     with warm peripheries
    anxiety tends to cause clammy hands


 phaeochromocytoma:
    especially if the patient is hypertensive
                               TFTs
T3 and T4 determination

TSH determination - normal serum TSH concentration nearly always
   excludes the diagnosis of thyrotoxicosis; the rare exceptions to
   this are a TSH-producing pituitary tumour or thyroid hormone
   resistance syndrome.

TRH stimulation test (rarely performed)

radioisotope iodine scanning

serology
                 Other tests

 FBC:
    normochromic normocytic anaemia may be
     seen in Graves' disease

 ESR:
    raised in Graves' disease
    high in subacute thyroiditis

 Calcium - often raised

 LFTs - may be abnormal in Graves' disease
            MANAGEMENT
 Admit if the person has severe signs and symptoms of
  hyperthyroidism (e.g. fever, agitation, heart failure,
  confusion, or coma) or is systemically unwell.

 Otherwise, refer all other individuals with overt
  hyperthyroidism for specialist management. The need
  for treatment should be based on the degree of
  elevation of serum free thyroxine (FT4) and free
  triiodothyronine (FT3) and clinical symptoms and signs
  as well as the cause of hyperthyroidism:
    The decision to initiate treatment with a thionamide
       (carbimazole or propylthiouracil) in primary care
       should be made under specialist advice.

 Consider a beta-blocker for symptomatic treatment or
  if a contraindicated, seek specialist advice regarding
  alternative drug treatment (e.g. diltiazem).
Hypothyroidism
Primary hypothyroidism


Common:
 chronic autoimmune thyroiditis
 Hashimoto's disease
 following thyroidectomy or radioiodine treatment
 iodine deficiency or, rarely, gross excess
 drug-induced
 de Quervain's thyroiditis - usually transient
 silent thyroiditis - usually transient; may be permanent

Uncommon:
 post-external beam irradiation to the neck
 congenital causes
 infiltrative disease:
     sarcoidosis
     systemic amyloidosis
         Secondary Hypothyroidism




Uncommon and is usually caused by:
 panhypopituitarism

 hypothalamic lesion with isolated TSH deficiency
             Management
Treat overt hypothyroidism with
  levothyroxine.

All people who are stable on levothyroxine
  require at least annual measurement of
  serum thyroid-stimulating hormone (TSH):
   To check compliance
   To ensure that the dosage is still correct
    Ongoing management
 Aim to achieve a serum thyroid-stimulating hormone
  (TSH) concentration that is within the reference
  range (0.4–4.5 mU/L).

 In the elderly, younger people and those with IHD
  start with small dose (25-50mcg) and titrate at 2-3
  month intervals with 25-50mcg steps

 Measure TSH and free thyroxine (FT4) 2–3 months
  after each change in dose of levothyroxine.

 Most people have a normal serum TSH
  concentration on a maintenance dose of 75–150
  micrograms of levothyroxine daily.
When to refer- Hypothyroidism
 Secondary hypothyroidism is suspected (refer urgently).
 Subacute Thyroiditis(de Quervain's thyroiditis) is suspected.
 Hypothyroidism is thought to be due toend organ
    resistance.
   They are younger than 16 years of age.
   They are pregnant or postpartum.
   They have particular management problems (e.g.
    ischaemic heart disease, or being treated with
    amiodarone or lithium).
   They feel worse during treatment, as they may have
    undiagnosed adrenal disease.
   They have continuing symptoms after appropriate
    thyroxine treatment (i.e. thyroid function tests are now
    within the reference ranges) to investigate for a non-
    thyroid cause of the symptoms
              Case study 1
 Monday morning
 72 year old living independently and rarely comes to the
  doctors. She had lost her purse on three occasions within
  the last fortnight and her son had arrived for his monthly
  visit on Monday to find she thought it was a Sunday and
  was upset that her cat was missing (the cat had died 2 years
  ago).
 He has brought her to you today. The patient appears upset
  in surgery that due to a misunderstanding she has had to
  miss church and come to the surgery. She is apologetic for
  using up your spare time. Her main complaint is her eyes
  which feel sore and watery and she says she is getting
  breathless going up the stairs.
 On examination she has a pulse of 90 which
  is irregular. She has sparse bibasal creps on
  auscultation of the chest. Her urine dip is
  negative and the remainder of the
  examination is unremarkeable. Her eyes are
  reddened. Her BMI is 18 and you notice
  that her wedding ring is loose on her finger.
  BP is 180/100
 The son is ok to stay with her for a fortnight
  and neither are keen for a hospital admission.
 Thyroid function tests come back within the
  day as
 T4 27, TSH 0.01.
 She is given:
 Carbimazole 20mg od (pt has low BMI)
 Aspirin
 Lubricating eye drops
 Refer to endocrinologist
 Son wants to know how long it will take for
  mother to be able to be left alone again.
 Son asks about side effects of ‘toxic’
  medication.
 In the older population, thyroid disease can
  present in different ways – confusion which
  is not acute in onset and vague
  constitutional symptoms. In any acute
  confusional state it is reasonable that if you
  do not have an obvious cause, to do thyroid
  function tests.
 Thyroid eye disease (exclusive to Grave’s disease)
  leaves patients with sore watery eyes and can be
  severe enough to restrict the eye movements and
  cause discomfort with eye movements. This may
  be helped with a course of high dose steroids and
  may require surgery but in less severe cases, a
  bottle of hypromellose is all that is required to
  provide comfort.
              Case Study 2

 36 yr old, presents with palpitations, lethargy and
  sore throat , worse on swallowing for 2 days. This
  was preceded by a cold with a cough but she feels
  she is getting worse and now getting hot and cold
  sweats. Routine examination reveals no
  abnormality in the ears, nose or throat and mild
  pyrexia of 37.9.

 What else would you check?
 Neck glands…… Tender anterior neck,
 worse on swallowing. There is no palpable
 goitre

 Pulse…… Rate 110 ?related to fever
 deQuervains thryroiditis – uncommon post viral
  inflammation of thyroid gland. There may or may
  not be a palpable goitre but the thyroid gland will
  be tender. The patient will have symptoms of
  hyperthyroidism at the outset and this is
  accompanied by a pyrexia.
 The condition is self limiting (within months) and
  usually follows course of hyperthyroidism,
  hypothyroidism then euthyroidism. Due to viral
  cause, no antibiotics are indicated and treatment
  options include NSAIDs, prednisolone and beta
  blockers for symptom control.
 Refer endocrinologist for monitoring.
              Case Study 3

9 year old boy with lump in the neck approx pea
   sized. Non tender. No other symptoms.
On examination lump is on left side of thyroid gland
Do you
a. Reassure?
b. Check TFTs?
c. Arrange ultrasound and fine needle aspiration
   cytology?
d. Refer to Thyroid surgeon?
 Answer is d. This patient fulfils the 2-week
  urgent cancer referral for head and neck.
 A Thyroid swelling associated with any
          one of the following:

 A solitary nodule increasing in size
 A history of neck irradiation
 A family history of an endocrine
  tumour
 Unexplained hoarseness or voice
  changes
 Very young (pre-pubertal) patient
 Patient aged 65 years and older
 The reason why you do no other tests before
  referral is that this may cause unnecessary
  delay to the patient’s diagnosis and
  treatment. Once the 2-week rule cancer
  referral has been received the department
  can organise any scans or tests much faster
  than you would be able to in primary care.