T1 L8 :Thyroid Disease Flashcards
what are the thyroid function diagnosis for patients with a goitre?
Hyperthyroid
Euthyroid (normal thyroid function)
Hypothyroid
what is thyrotoxicosis
Overproduction of the thyroid hormone
what do thyroid function tests test for
TSH FT3 FT4 thyroid autoantibodies-Anti-TPO AB - Thyroid peroxidase auto-antibody TRAB - TSH receptor autoantibody
what is a bruit
A thyroid bruit is seen in Grave’s disease from a proliferation of the blood supply when the thyroid enlarges- rush of blood causing a noise heard with a stethoscope
a bruit can help to distinguish a goitre from a
Toxic adenoma
TSH is the best biomarker for thyroid status but how long do the levels take to change in reflection to treatment?
6 weeks
If there is an abundance of autoantibodies
Auto-immune disease
What is a symptom of hypothyroidism
Facial puffiness
Dry skin
Hair loss
what are the extreme signs for hypothyroidism
Diffuse hair loss
Bradycardia
Effusions, eg ascites, pericardial
what are the causes of Causes of Primary Hypothyroidism Give 3
Autoimmune hypothyroidism
Hypothyroidism after treatment
for hyperthyroidism (iatrogenic)
Thyroiditis
Drugs (e.g. lithium, amiodarone)
Congenital hypothyroidism
Iodine deficiency (not UK)
what are the levels of biomarkers for primary hypothyroidism
Increased TSH
Low T4 and T5
what are the causes of secondary hypothyroidism
diseases of the
hypothalamus
or pituitary
what are the levels of biomarkers in secondary thyroid diseases
A low TSH
Low T4 and low T3
when looking at results how do you interpret them
Look at FT4 levels- determines hypo/hyper
look at TSH- determines primary or secondary
what is the treatment for hypothryoidism
Start with thyroxine (T4) 100 g daily
Aim normal FT4 without TSH suppression
what is the dose if patients are elderly
Unless elderly/ischaemic heart disease
Start 25 g daily with increments 4-6 weekly
what does Myxoedema mean
a coma -accumulation of glycosaminoglycans in interstitial spaces of tissues
what is graves disease
Chronic autoimmune-antibody working on TSH receptors hyperthyr…
what is Chronic autoimmune thyroiditis
Hashimoto’s disease
With a goitre
With a lymphocytic infiltration
what is thyroiditis
Blip of high T4 then extremely low - longer hypothyroidism associated with pregnancy or 1 year post
partum
The goitre is tender
why can pregnancy cause hyperthyroidism
Gestational thyrotoxicosis
HCG in abundance similar in structure to TSH and stimulates receptors but only for 1st trimester
what are the symptoms of hyperthyroidism
Weight loss
Lack of energy
Heat intolerance
Anxiety/irritability
what are the signs of hyperthyroidism
Tremor Warm, moist skin Tachycardia Brisk reflexes Eye signs
what are the symptoms of Symptoms of thyroid eye disease (TED)
Mild’ symptoms:
‘itchy’ / dry eyes
Artificial tears help
‘prominent’ eyes
worse symptoms : Diplopia / loss of sight Loss of colour vision Grey / blurred patches Redness / swelling of conjunctiva
Give 2 signs for each area of the body for hyperthyroidism Neck, hands, pulse and eyes
Hands:
Fine tremor
Warm
Pulse:
Sinus tachycardia
Atrial fibrillation
Neck:
Goitre
Move when swallow
Eyes
Lid retraction / lid lag
Proptosis / exophthalmos
what is the cause of autoimmune thyrotoxicosis
Autoantibody stimulates the
TSH receptor, causing excess
thyroid hormone production
and thyroid growth (goitre)
what are the other causes of thyrotoxicosis
Toxic multinodular goitre
Toxic adenoma
Thyroiditis
Drugs (e.g. amiodarone)
how to differentiate between graves and normal hyperthyroidism
- Personal or family history of any autoimmune thyroid / endocrine disease
- Goitre with a bruit = Graves disease
- Thyroid eye disease = Graves disease (20%)
- Positive thyroid autoantibody titre
Further investigations
Thyroid autoantibodies
Thyroid uptake scan (isotope scan)
Functional scan: darker areas of increased activity
what are the treatment options for graves disease
Medical
Radioiodine
Surgery
Symptom control
β-blockers (propranolol)
Not if asthmatic
Risks of no treatment Symptoms worsening Atrial fibrillation Stroke Osteoporosis Fractures
what can RADIOIODINE be used for
Oral treatment, radioiodine concentrated in thyroid, radiation kills thyroid cells
Medical therapy first till euthyroid
Treatment for a toxic adenoma or toxic multinodular goitre
Initial treatment: short term medical therapy (to control thyroid function tests)
Subsequent curative treatment: radioiodine
how can you treat thyroid eye disease
- Steroids
- Pulsed IV methylpred / oral prednisolone
- Other immunosuppressive / steroid-sparing agents
- Radiotherapy
what is Thyroid storm
Multi-system
Graves
Goitre, thyroid eye disease
hyperpyrexia
CNS
Agitation, delirium
Cardiovascular Tachycardia >140 bpm Atrial dysrhythmias Ventricular dysfunction Heart failure
GI
Nausea & vomiting
Diarrhoea
Hepatocellular dysfunction
when would you consider thyroiditis
Consider if:
Patient is pregnant / within 1 year post-partum
risk T1 diabetes, FHx thyroid disease, smoker
Patient has very tender thyroid
Clinical thyroid status does not fit with lab results-rapidly changing TSH and long hypo operiod
(Rapidly changing thyroid function tests)
No diagnostic features of Graves disease
Current / recent treatment with immunomodulatory medication
Association of autoimmune thyroid disease with other diseases
Type 1 diabetes
Pernicious anaemia
Coeliac disease
Turner syndrome
Down’s syndrome
Addisons disease
Medication for other diseases
Lithium
Inhibits thyroid hormone synthesis & secretion
Amiodarone
