Acrocyanosis

Acrocyanosis is characterised by painless discoloration, of different shades of blue, affecting the extremities. The colour change has relative persistence with aggravation by cold exposure, and the condition is frequently associated with localised hyperhidrosis.

This chapter is set out as follows:

• Primary acrocyanosis is idiopathic

• Secondary acrocyanosis has numerous causes including hypoxaemia, connective tissue disorders, cryoglobulinaemia, the antiphospholipid syndrome, malignancy (eg paraproteinaemia), anorexia nervosa, and it can be drug-induced

• Idiopathic acrocyanosis usually starts in adolescence and persists into adult life

• Pain or significant discomfort is uncommon

• Bluish discoloration of the skin may have different hues, affecting fingers and toes and involving, in some cases, the entire hands and feet and even forearms

• Parts of the head, especially the nasal tip and ears, may be affected although less frequently

• Almost all acrocyanosis patients have marked clamminess and hyperhidrosis of hands and feet, which may be very striking on the volar surfaces and tend to worsen in warmer temperatures while the color changes improve

• Most often, acrocyanosis is confused with Raynaud’s phenomenon as both are aggravated by cold and emotional stress; both present with blue discoloration of the fingers and hyperhidrosis. Acrocyanosis is differentiated from Raynaud’s phenomenon by relative persistence of skin color changes, and absence of paroxysmal pallor. However, episodes of Raynaud’s superimposed on acrocyanosis are not uncommon and may complicate the diagnosis. While Raynaud’s phenomenon is marked by clear paroxysms, the persistence of color changes in acrocyanosis is also relative as many cases will improve in the summer

• Cases of primary acrocyanosis starting in young patients who are otherwise well require only limited investigations eg FBC and standard biochemistry

• Where secondary acrocyanosis is suspected (eg starting in adults, presence of pain, asymmetry, ulceration and necrosis, livedo reticularis, or other significant skin changes) more detailed investigations are required along the lines of those for connective tissue disorders and vasculitis

• This is usually a benign condition without any serious complications, except in cases of secondary acrocyanosis with underlying serious disease

• Drug-induced acrocyanosis will improve on cessation of the causal drug

• Treatments such as calcium-channel blockers are ineffective