• Family history (either autosomal recessive, which is most common, or autosomal dominant; the gene for both forms has been mapped to chromosome 16, Human Mol Genet 1997;6:1823)

• Upper GI haemorrhage, myocardial infarction, stroke and intermittent claudication, visual loss

• Hypertension (from involvement of renal vasculature)

• Intracranial haemorrhage.

• Fundus shows angioid streaks: linear grey or dark red streaks with irregular edges lying beneath the retinal vessels (Fig. 176.1) (roughly 50% of patients with angioid streaks have pseudoxanthoma elasticum, whereas 85% of those with pseudoxanthoma have angioid streaks).

• Look at the neck (Fig. 176.2), antecubital fossae, axillae (Fig. 176.3), groin and periumbilical region for loose ‘chicken skin’ appearance of skin

• Examine peripheral pulses: absent pulses from peripheral arterial involvement but acral ischaemia is uncommon because of development of collaterals.

• Small yellow papules arranged in a linear or reticular pattern in plaques on the neck, axillae, cubital fossae, periumbilical region and groin

• Tell the examiner that you would like to examine the fundus.