An Overview of Acrocyanosis

Acrocyanosis is a condition that causes the hands and feet to turn blue. The main cause of this is the constriction of the tiny arteries at the ends of the arms and legs. It is often seen in infants, small children, teens, and young people. In newborns, it is common in the first few hours of life. 

The condition name comes from the Greek words "akros," which means extreme, and "kyanos," which means blue. One report on acrocyanosis points out the lack of clarity and consensus in the medical community about whether it is a single disease or whether it's always related to specific causes—it is not a well-researched condition.

What researchers do know for sure is that there are two types of acrocyanosis: primary and secondary. Learning more about the symptoms and the underlying causes of each type helps to shed light on the condition as a whole.

The hands and feet are most commonly affected in acrocyanosis. However, the condition can also affect the nose, ears, lips, nipples, wrists, and ankles as well.

Primary acrocyanosis is symmetrical, meaning it affects both sides of the body. For example, if it is found on the hands, it exists on both of the hands. Secondary acrocyanosis, on the other hand, affects only one side. Secondary acrocyanosis is usually painful and may cause tissue loss.

The most common symptoms of each type of acrocyanosis are:

• blue-colored fingers or toes
• cold and sweaty hands and feet
• low skin temperatures
• slow blood flow
• swelling in hands and feet

Primary acrocyanosis in newborns occurs because blood and oxygen are flowing to the brain, lungs, kidney, and other important parts of the body first—not the hands and feet. Newborns who have bluish colored hands and feet will improve within the first few hours once the body gets used to the new blood circulation pattern.

The causes of acrocyanosis are dependent on whether it is primary or secondary.

Primary acrocyanosis may be caused by cold temperatures. It is not harmful, but it is often confused with Raynaud’s disease, which is a disorder where the body overreacts to certain situations causing coldness and numbness in the hands and feet. (Raynaud's, on the other hand, is often a cause of secondary acrocyanosis.)

Researchers believe that primary acrocyanosis is caused by constriction of the small blood vessels that deliver oxygen-rich blood to the extremities. This constriction may be due to cold temperatures, living in areas of high altitudes with lower oxygen pressure and increased cold temperatures and wind, and genetic defects in the blood vessels.

In newborns, the cause of primary acrocyanosis is the change in circulation after birth. 

Secondary acrocyanosis causes pain and has numerous causes including infections, vascular diseases, blood disorders, eating disorders, cancer, and genetic causes. The most common causes of secondary acrocyanosis are Raynaud’s disease and eating disorders.

A diagnosis of acrocyanosis is made by physical examination and medical history, including the assessment of symptoms.

A diagnosis of primary acrocyanosis is made based when there is a bluish color of hands and feet (and sometimes the nose and ears), when hands and feet are cold and sweaty, and when symptoms are not causing pain. When there is not any pain, the blue color is not associated with a disease of impaired circulation.  

Circulation in the small blood vessels can be measured using a non-invasive technique called capillaroscopy, which examines the capillaries at the nailbeds. 

When secondary acrocyanosis is suspected, other testing and images may be done to determine the cause of symptoms. Other tests may be done to rule out other conditions that also cause the extremities to turn blue, including Raynaud’s. 

There is no specific treatment for acrocyanosis; however, symptoms can be managed. 

In babies, warming the body temperature can resolve symptoms. In older children and adults, keeping hands and feet warm and covering up their body parts can protect from cold temperatures.

Severe cases may be treated with medications including alpha blockers or medications that relax muscles and help small blood vessels to remain open. Secondary acrocyanosis symptoms resolve when the underlying condition is treated and managed.                                                                              

Primary acrocyanosis is a generally harmless condition with a good outlook. Treatments are available to lessen symptoms in severe cases. In newborns, the condition dissipates on its own and doesn’t return once symptoms resolve. The underlying causes of secondary acrocyanosis can be serious. It is a good idea for anyone with symptoms of acrocyanosis to contact their doctor. That way the underlying condition can be treated and complications of that condition can be avoided.