Painful blue finger: Achenbach's syndrome.

Abstract

A previously healthy 60-year-old male patient presented with sudden pain and bruising in his left little finger, which occurred at home shortly before his visit. At the time, he noticed a bluish discolouration on the palmar aspect of the finger and became concerned that it might be a sign of a serious vascular or haematological disease. He had no history of preceding trauma, cold exposure or medication. Physical examination revealed a subcutaneous haematoma with slight swelling but without coldness or paresthesia (figure 1A). Allen's test and capillary refilling were normal. Laboratory tests revealed a normal platelet count and coagulation function. Based on these findings, Achenbach's syndrome (paroxysmal finger haematoma) was clinically diagnosed, and the patient was observed without treatment. The discolouration and pain resolved spontaneously 6 days later (figure 1B). Achenbach's syndrome was first described in 1958 by Walter Achenbach.1 It is a rare cause of finger pain characterised by ecchymotic discolouration with sudden pain onset in the fingers or hands. Although the aetiology is unknown, it is a self-limiting condition found predominantly in middle-aged women.2 The diagnosis is based on the typical clinical presentation, and examinations reveal no specific abnormalities. The differential diagnosis includes acute limb ischaemia, trauma, Raynaud's syndrome, acrocyanosis, Gardner-Diamond syndrome and chilblain.2 The most emergent differential diagnosis is acute limb ischaemia, which can be distinguished from Achenbach's syndrome by the non-involvement of the digit tips.3 Clinicians should be aware of this entity to avoid unnecessary tests and to reassure patients of its benign prognosis.