Myxoedema coma

Profound hypothyroidism typically presenting with hypothermia, bradycardia and impaired level of conciousness.

General examination

To diagnose hypothyroidism a detailed and full general examination is mandatory in the initial assessment of a patient. 

The patient with myxoedema may have a typical appearance of waxy, doughy skin, thinned hair, cool peripheries, and reduced conscious level.

Temperature

The patient wtih myxoedema is usually hypothermic.

Cardiovascular system

Detailed emergency cardiac assessment is necessary.

Bradycardia and other arrhythmias typically occur in profound hypothyroidism.

Hypotension will usually reflect low output cardiac failure due to bradycardia, but may also indicate glucocorticoid deficiency with coincident Addison’s disease.

Fluid overload due to myxoedema can also complicate this presentation and requires very careful assessment.

Skin and hair

Dry skin with diffuse hair loss may be seen in hypothyroidism.

Doughy pallid 'myxoedematous' skin may also be seen with loss of thyroid function.

Fine wrinkling of the skin occurs in thyroid dysfunction due to hypopituitarism.

Pallor may also occur with anaemia and glucocorticoid deficiency of any cause, for example pernicious anaemia, coeliac disease or pituitary dysfunction.

Deeply tanned skin with pigmentation of scars may indicate Addison’s disease.

Patches of symmetrical depigmentation of both hair and skin may occur with vitiligo.

Patches of complete hair loss indicate associated alopecia areata.

Pretibial myxoedema - pinkish discolouration over thinned and yellow tinged skin of the shins, with or without oedema - may occur with hypothyroidism.

Respiratory examination

Hypopnoea may lead to hypoxia and hypercapnoea.

Pleural effusions may also be present.

Gastrointestinal examination

Paralytic ileus and faecal impaction may occur.

Neurological examination

Altered mental state is almost universal with profound hypothyroidism, though actual "coma" is rare.

Myopathy may be difficult to assess, but slow relaxing reflexes are invariably evident.