Hypothyroidism

Question 1

Hypothyroidism Epidemiology

Answer 1

• Increases with age

- Most common cause is iodine deficiency

Question 2

Hypothyroidism Aetiology

Answer 2

Primary

• Autoiummune (Hashimoto’s)- associated with goitre, if no goitre, atrophic
• Iatrogenic- radio-iodine treatment
• Drugs- Amiodarone
• Congenital,
• Infiltration (amyloidosis, sarcoidosis)

Secondary

• Isolated TSH deficiency
• Hypopituitarism (neoplasm, infiltrative, infection, radiotherapy)
• Hypothalamic disorders (neoplasms and trauma)

Question 3

Hypothyroidism Symptoms

Answer 3

• Insidious onset, symptoms may develop over years
• Tiredness, lethargy, intolerance to cold, dry skin, hair losss
• Slowing of intellectual activity
• Constipation, decreased appetite, menorrhagia
• Hearing
• Myxoedema, bradycardia

Myxoedema

• Expressionless, dull face with peri orbital puffiness
• Pale, cool skin, with doughy texture

Question 4

Hashimoto’s vs Atrophic Hypothyroidism

Answer 4

• Both represent different ends of same spectrum
• Hashimoto’s can range from normal to subclinical to overt, with a rubbery, irregular goitre
• Atrophic represents end stage, patients are overtly hypothyroid, no goitre

Question 5

Hypothyroidism Ix

Answer 5

• TFTs
• Offer to those with autoimmune disease or new onset AF
• Anti-thyroid peroxidase (anti-TPO) found in autoimmune thyroiditis
• If goitre asymmetrical, image to rule out neoplasm

Question 6

Hypothyroidism Management

Answer 6

• Levothyroxine
• Measure TSH every three months until level has stabilised
• Drugs that interfere with treatment; ferrous sulphate, calcium supplements, rifampicin, Amiodarone
• Euthyroidism is important for conception and pregnancy

Question 7

Hypothyroidism Subclinical

Answer 7

• Raised TSH, normal T3/T4
• Always treat those with subclinical hypothyroidism and positive anti-TPO or Hx of radio-iodine as they will almost always progress to overt hypothyroidism
• Otherwise, monitor

Question 8

Hypothyroidism Myxoedema Coma

Answer 8

• Seen mostly in elderly patients, associated with a mortality between 20% and 50%
• Infections and discontinuations are main cause
• Reduced level of consciousness, seizures, hypothermia
• IV levothyroxine
• Supportive therapy