Question:
I have been diagnosed with mixed connective tissue disease. The specialist also told me that my bluish/purple fingers and toes were "acrocyanosis." What is acrocyanosis, and what is its relationship to connective tissue disease?
Answer:
Mixed connective tissue disease (MCTD) is a rare condition of unknown cause. It is thought to be an autoimmune disease in which the immune system mistakenly attacks a number of normal tissues and organs in the body.
People with MCTD have a combination of medical problems with features typical of systemic lupus erythematosus (lupus), rheumatoid arthritis, polymyositis (a disease marked by muscle inflammation) and scleroderma. For example, a typical person suffering with MCTD might complain of joint swelling and stiffness in the hands and wrists, thickening of the skin, muscle weakness and a rash over the cheeks triggered by sun exposure.
A common and painful problem among people with scleroderma or MCTD is Raynaud's phenomenon, in which the fingers or toes change color from normal to white, blue (cyanotic), and then red. This usually follows exposure to cold. It is thought to represent an exaggeration of the normal constriction of blood vessels in response to cold temperature. As a result, blood flow into the small arteries of the fingers or toes suddenly decreases; over a number of minutes, the blood vessels open up, circulation improves and the fingers return to their normal color. Raynaud's phenomenon can also occur in otherwise healthy people.
Acrocyanosis indicates a blue discoloration in an extremity ("acro" = extremity, "cyanosis" = blue). Acrocyanosis that comes and goes over a short period of time is a common occurrence for anyone with Raynaud's phenomenon, and that is by far the most common cause of acrocyanosis among people with MCTD. However, there are other, less common causes of acrocyanosis. For example, a blood clot in the arm or frostbite could cause prolonged or fixed (constant) acrocyanosis in the hands, and peripheral vascular disease (due to atherosclerosis) may cause acrocyanosis in the feet.
