Graves Disease

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Definition

-  Primary autoimmune hyperthyroidism associated w infiltrative opthalmopathy & dermopathy

 

Features

-  Circulating IgG activates TSH receptor causing hyperthyroidism

-  Peak onset 40-60 yrs

-  Female 7:1 male

-  Thyrogastric AID

-  Cause of 85% of hyperthyroidism

-  May present in pregnancy

-  Most common cause of hyperthyroidism seen in pregnancy

-  S/S may improve in second half of pregnancy

-  S/S may worsen for several months post partum

-  Triggers

-  Stressful life event

-  Infection

-  Childbirth

 

Associated S/S

-  Opthalmic

-  Clinically evident in 30-50%

-  Evident on imaging 80%+

-  Chemosis

-  Exopthlamosis, proptosis

-  Opthalmoplegia: diplopia

-  Blurred vision

-  Acropachy (Periosteal bone formation)

-  Clubbing

-  Finger & toe swelling

- Pretibial Myxoedema

-  < 10% pts

-  Maculopapular rash

-  Pau d orange

-  Goitre

-  Thyroid Bruit

-  Men

-  Gynaecomastia

-  Reduced libido

-  Erectile dysfunction

-  S/S of hyperthyroidism

 

Ix

-  Thyroid Exam

-  TFTs

-  TSH: decreased

-  FT4, T3: elevated

-  Normal: subclinical hyperthyroidism

-  FT4 used for disease monitoring

-  TSH Receptor Ab

-  Not required for Dx or Mx

-  TBII

-  TSI

-  TPO Ab: not spec, also present in Hashimotos thyroiditis

-  Thyroid Scan: high uptake, increased blood flow, thyroid nodule

-  Thyroid US: thyroid nodule, blood flow

-  +/- FNA: thyroid adenoma

-  BMD

-  ECG: AF..

-  CT neck: goiter: obstruction

-  Orbital imaging

 

 

 

Mx

-  Beta blockers: symptomatic

-  Pregnancy test all women prior

-  Antithyroid Meds

-  Initial therapy

-  May cause agranulocytosis 0.1-0.3%

-  Rarely Aplastic anaemia

-  Propylthiouracil (PTU)

-  Inhibits TPO (thyroperoxidase)

-  Inhibits peripheral coversion of T4 to T3

-  Carbemazole

-  Inhibits TPO (thyroperoxidase)

-  Improvement in 3-4 weeks

-  Dose adjusted to serum FT4, T3 & TSH

-  Radioactive iodine (i131)

-  Initial therapy or after meds

-  Therapeutic or ablative dose

-  Discontinue meds 3-4 days

-  Induces hypothyroidism in 80%

-  May worsen opthalmopathy

-  Subtotal Thyroidectomy

-  Least often used Mx

-  More likely if goiter

-  Lifelong T4 replacement