Acute blue finger: a diagnostic challenge.

The management of the acute blue finger is controversial with many regarding it as a benign condition. However, we would argue that it should always be considered as an emergency. We present a challenging case of a 43-year-old woman who presented with a 1-week history of sudden onset blue discolouration of the left fifth digit, and a 6-week history of episodic joint problems. Examination showed bilateral normal radial and ulnar pulses. Following blood investigations, an initial working diagnosis of early rheumatoid arthritis with associated Raynaud's phenomenon was made. Also, infective endocarditis was considered due to temporary misleading physical signs. Later, CT angiography of the left upper limb arteries showed a significant proximal left subclavian stenosis. Subsequently, a diagnosis of the left subclavian arteritis associated with digit ischaemia from embolic debris was made and the patient underwent a left subclavian angioplasty. However, delayed management resulted in a necrotic digit, which was left to autoamputate.