A condition resulting from thyroid hormone deficiency

Causes

• Autoimmune disease

• Post-therapeutic (especially after radiotherapy or surgical treatment for hyperthyroidism)

• Secondary - due to enzyme defects

Clinical features

• Dull facial expression, puffiness, periorbital swelling
• Hoarse voice, slow speech
• Drooping eyelids
• Hair sparse, coarse and dry
• Skin coarse, dry, scaly and thick
• Forgetfullness, other signs of mental impairment
• Gradual personality change
• Bradycardia
• Constipation (often)
• Parasthesia (numbness) of hands and feet
• Anaemia (often)

Differential diagnosis

• Myasthenia gravis

Investigations

Blood levels of thyroid hormone (T3, T4, TSH)

Management
HC4

thyroxine 100 micrograms initially once daily before breakfast elderly: 50 micrograms

Depending on response:

- gradually increase by 25-50 micrograms every 4 wks to maintenance dose of 100-200 micrograms daily

child: thyroxine 1 microgram/kg daily for the first 6 months, then adjust according to response

- max: 100 micrograms daily

Prevention

• Educate patients on the use of iodised salt