Achenbach’s Syndrome: A Differential of Unidigital Raynaud’s

A 65-year-old lady had sudden-onset bluish-black discoloration of the right middle finger, with pain and swelling. It spontaneously resolved over one week. She had similar episodes in the past involving the same finger. She denied any history suggestive of connective tissue disease, prior trauma, or aggravation of these symptoms with cold exposure or emotional stress. Physical examination was notable for a mildly tender, swollen right middle finger with a reddish-blue discoloration (Figure 1). Capillary refill time was normal, and all peripheral pulses were palpable. Investigations showed a normal platelet count and no evidence of coagulopathy. Autoantibody testing was negative. Nail-fold capillaroscopy and arterial doppler of bilateral upper limbs were normal. She was thus diagnosed with Achenbach’s syndrome after ruling out other potential causes.

Figure 1.

Bluish-black Discoloration of Right Middle Finger with Swelling.

Achenbach’s syndrome had originally been described by the German physician Walter Achenbach in 1956. ¹ Achenbach’s syndrome, also known as ‘painful blue finger’ or ‘paroxysmal finger haematoma’ is a rare benign condition of unknown aetiology, that is predominantly seen in females in their fifth decade. It manifests as sudden-onset bruising with painful swelling, particularly on volar aspects of fingers. The right middle finger is most commonly affected. Although asymptomatic resolution occurs in a few days with no sequelae, recurrences are well described. ² Since it is a benign, spontaneously resolving condition requiring no specific treatment, physicians should be aware of this rare entity to reassure patients and avoid unnecessary invasive investigations.