Acrocyanosis
Encyclopedia
Acrocyanosis is persistent blue or cyanotic
discoloration of the extremities, most commonly occurring in the hands, although it also occurs in the feet and distal parts of face.
Although described over 100 years ago and not uncommon in practice, the nature of this phenomenon is still uncertain. The very term "acrocyanosis" is often applied inappropriately in cases when blue discoloration of the hands, feet, or parts of the face is noted.
The principal (primary) form of acrocyanosis is that of a benign
cosmetic condition, sometimes caused by a relatively benign neurohormonal
disorder. Regardless of its cause, the benign form typically does not require medical treatment. A medical emergency
would ensue if the extremities experience prolonged periods of exposure to the cold, particularly in children and patients with poor general health. However, frostbite
differs from acrocyanosis because pain (via thermal nociceptor
s) often accompanies the former condition, while the latter is very rarely associated with pain. There is also a number of other conditions that affect hands, feet, and parts of the face with associated skin color changes that need to be differentiated from acrocyanosis: Raynaud’s phenomenon, pernio, acrorygosis, erythromelalgia, blue finger syndrome. The diagnosis may be challenging in some cases, especially when these syndromes co-exist.
Acrocyanosis may be a sign of a more serious medical problem, such as connective tissue diseases and diseases associated with central cyanosis. Other causative conditions include infections, toxicities, antiphospholipid syndrome, cryoglobulinemia, neoplasms. In these cases, the observed cutaneous changes are known as "secondary acrocyanosis". They may have a less symmetric distribution and may be associated with pain and tissue loss.
(especially in the warmer weather). The palms and soles exhibit a wide range of sweating from moderately moist to profuse, but all peripheral pulse
s should have normal rate, rhythm, and quality. Exposure to cold temperatures worsens the cyanosis, while it often improves on warming. Aside from the color changes, patients normally are asymptomatic and therefore there is usually no associated pain. The most common sign, discoloration, usually is what prompts patients to seek medical care.
of acrocyanosis is unknown. The current line of thinking goes that vasospasm
s in the cutaneous arteries and arterioles produce cyanotic discoloration, while compensatory dilatation in the postcapillary venule
s causes sweating. Arteriovenous subpapillary plexus shunting also occurs. Persistent vasoconstriction at the precapillary sphincter
creates a local hypoxic environment, thus releasing adenosine into the capillary bed. Vasospasms force adenosine to enter the capillary bed, where it vasodilates the postcapillary venules. Such differences in vessel tone create a countercurrent exchange
system that attempts to retain heat. Profuse sweating would then be caused by an overwhelmed countercurrent exchange system. In addition to adenosine, other hormones may contribute to acrocyanosis such as increase blood levels of serotonin. This would seem to support case studies reporting acrocyanosis as an unusual side effect for pediatric patients taking tricyclic antidepressant
s, as these medications can inhibit the reuptake of serotonin and thus increase their blood concentrations. Acrocyanosis has been reported in association with many other medications and substances.
and physical examination
; laboratory studies or imaging studies are not necessary. The normal peripheral pulses rule out peripheral arterial occlusive disease, where arterial
narrowing limits blood flow to the extremities. Pulse oximetry
will show a normal oxygen saturation
. Unlike the closely related Raynaud's phenomenon
, cyanosis is continually persistent. In addition, there is usually no associated trophic skin changes, localized pain, or ulcerations. Capillaroscopy and other laboratory methods may be helpful but only complement clinical diagnosis in unclear cases, especially when connective tissue disorders may be present.
would alleviate the cyanosis by disrupting the fibers of the sympathetic nervous system
to the area. However, such an extreme procedure would rarely be appropriate. Treatment with vasoactive drugs is not recommended but traditionally is mentioned as optional. However, there is little, if any, empirical evidence that vasoactive drugs (α-adrenergic blocking agents
or calcium channel blockers) are effective.
, acrocyanosis shows prevalence
in children and young adults than in patients thirty years of age or older. Epidemiological
data suggests that cold climate, outdoor occupation, and low body mass index
are significant risk
factors for developing acrocyanosis. As expected, acrocyanosis would be more prevalent in women than in men due to differences in BMI. However, the incidence rate of acrocyanosis often decreases with increasing age, regardless of regional climate. It completely resolves in many women after menopause implying significant hormonal influences.
and full term
newborn Intervention normally is not required, although hospitals opt to provide supplemental oxygen for precautionary measures.
Cyanosis
Cyanosis is the appearance of a blue or purple coloration of the skin or mucous membranes due to the tissues near the skin surface being low on oxygen. The onset of cyanosis is 2.5 g/dL of deoxyhemoglobin. The bluish color is more readily apparent in those with high hemoglobin counts than it is...
discoloration of the extremities, most commonly occurring in the hands, although it also occurs in the feet and distal parts of face.
Although described over 100 years ago and not uncommon in practice, the nature of this phenomenon is still uncertain. The very term "acrocyanosis" is often applied inappropriately in cases when blue discoloration of the hands, feet, or parts of the face is noted.
The principal (primary) form of acrocyanosis is that of a benign
Benign
A benign tumor is a tumor that lacks the ability to metastasize. Common examples of benign tumors include moles and uterine fibroids.The term "benign" implies a mild and nonprogressive disease. Indeed, many kinds of benign tumors are harmless to human health...
cosmetic condition, sometimes caused by a relatively benign neurohormonal
Neurohormone
A neurohormone is any hormone produced and released by neurons.Examples include:*Thyrotropin-releasing hormone *Gonadotropin-releasing hormone *Adrenocorticotropin-releasing hormone*Oxytocin*Antidiuretic hormone *Epinephrine...
disorder. Regardless of its cause, the benign form typically does not require medical treatment. A medical emergency
Medical emergency
A medical emergency is an injury or illness that is acute and poses an immediate risk to a person's life or long term health. These emergencies may require assistance from another person, who should ideally be suitably qualified to do so, although some of these emergencies can be dealt with by the...
would ensue if the extremities experience prolonged periods of exposure to the cold, particularly in children and patients with poor general health. However, frostbite
Frostbite
Frostbite is the medical condition where localized damage is caused to skin and other tissues due to extreme cold. Frostbite is most likely to happen in body parts farthest from the heart and those with large exposed areas...
differs from acrocyanosis because pain (via thermal nociceptor
Nociceptor
A nociceptor is a sensory receptor that responds to potentially damaging stimuli by sending nerve signals to the spinal cord and brain. This process, called nociception, usually causes the perception of pain.-History:...
s) often accompanies the former condition, while the latter is very rarely associated with pain. There is also a number of other conditions that affect hands, feet, and parts of the face with associated skin color changes that need to be differentiated from acrocyanosis: Raynaud’s phenomenon, pernio, acrorygosis, erythromelalgia, blue finger syndrome. The diagnosis may be challenging in some cases, especially when these syndromes co-exist.
Acrocyanosis may be a sign of a more serious medical problem, such as connective tissue diseases and diseases associated with central cyanosis. Other causative conditions include infections, toxicities, antiphospholipid syndrome, cryoglobulinemia, neoplasms. In these cases, the observed cutaneous changes are known as "secondary acrocyanosis". They may have a less symmetric distribution and may be associated with pain and tissue loss.
Signs and symptoms
Acrocyanosis is characterized by peripheral cyanosis: persistent cyanosis of the hands or of the hands, feet, or face. The extremities often are cold and clammy and may exhibit some swellingEdema
Edema or oedema ; both words from the Greek , oídēma "swelling"), formerly known as dropsy or hydropsy, is an abnormal accumulation of fluid beneath the skin or in one or more cavities of the body that produces swelling...
(especially in the warmer weather). The palms and soles exhibit a wide range of sweating from moderately moist to profuse, but all peripheral pulse
Pulse
In medicine, one's pulse represents the tactile arterial palpation of the heartbeat by trained fingertips. The pulse may be palpated in any place that allows an artery to be compressed against a bone, such as at the neck , at the wrist , behind the knee , on the inside of the elbow , and near the...
s should have normal rate, rhythm, and quality. Exposure to cold temperatures worsens the cyanosis, while it often improves on warming. Aside from the color changes, patients normally are asymptomatic and therefore there is usually no associated pain. The most common sign, discoloration, usually is what prompts patients to seek medical care.
Pathophysiology
The precise etiologyEtiology
Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....
of acrocyanosis is unknown. The current line of thinking goes that vasospasm
Vasospasm
Vasospasm refers to a condition in which blood vessels spasm, leading to vasoconstriction. This can lead to tissue ischemia and death . Cerebral vasospasm may arise in the context of subarachnoid hemorrhage. Symptomatic vasospasm or delayed cerebral ischemia is a major contributor to...
s in the cutaneous arteries and arterioles produce cyanotic discoloration, while compensatory dilatation in the postcapillary venule
Venule
A venule is a very small blood vessel in the microcirculation that allows deoxygenated blood to return from the capillary beds to the larger blood vessels called veins. Venules range from 8 to 100μm in diameter and are formed when capillaries unite .Venules are blood vessels that drain blood...
s causes sweating. Arteriovenous subpapillary plexus shunting also occurs. Persistent vasoconstriction at the precapillary sphincter
Precapillary sphincter
The precapillary sphincter is a band of smooth muscle that adjusts the blood flow into each capillary. At the point where each true capillary originates from a metarteriole, a smooth muscle fiber usually encircles the capillary. This is called the precapillary sphincter. This sphincter can open and...
creates a local hypoxic environment, thus releasing adenosine into the capillary bed. Vasospasms force adenosine to enter the capillary bed, where it vasodilates the postcapillary venules. Such differences in vessel tone create a countercurrent exchange
Countercurrent exchange
Countercurrent exchange is a mechanism occurring in nature and mimicked in industry and engineering, in which there is a crossover of some property, usually heat or some component, between two flowing bodies flowing in opposite directions to each other. The flowing bodies can be liquids, gases, or...
system that attempts to retain heat. Profuse sweating would then be caused by an overwhelmed countercurrent exchange system. In addition to adenosine, other hormones may contribute to acrocyanosis such as increase blood levels of serotonin. This would seem to support case studies reporting acrocyanosis as an unusual side effect for pediatric patients taking tricyclic antidepressant
Tricyclic antidepressant
Tricyclic antidepressants are heterocyclic chemical compounds used primarily as antidepressants. The TCAs were first discovered in the early 1950s and were subsequently introduced later in the decade; they are named after their chemical structure, which contains three rings of atoms...
s, as these medications can inhibit the reuptake of serotonin and thus increase their blood concentrations. Acrocyanosis has been reported in association with many other medications and substances.
Diagnosis
Acrocyanosis is diagnosed clinically, based on a medical historyMedical history
The medical history or anamnesis of a patient is information gained by a physician by asking specific questions, either of the patient or of other people who know the person and can give suitable information , with the aim of obtaining information useful in formulating a diagnosis and providing...
and physical examination
Physical examination
Physical examination or clinical examination is the process by which a doctor investigates the body of a patient for signs of disease. It generally follows the taking of the medical history — an account of the symptoms as experienced by the patient...
; laboratory studies or imaging studies are not necessary. The normal peripheral pulses rule out peripheral arterial occlusive disease, where arterial
Artery
Arteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....
narrowing limits blood flow to the extremities. Pulse oximetry
Pulse oximetry
Pulse oximetry is a non-invasive method allowing the monitoring of the oxygenation of a patient's hemoglobin.A sensor is placed on a thin part of the patient's body, usually a fingertip or earlobe, or in the case of an infant, across a foot....
will show a normal oxygen saturation
Oxygen saturation
Oxygen saturation or dissolved oxygen is a relative measure of the amount of oxygen that is dissolved or carried in a given medium. It can be measured with a dissolved oxygen probe such as an oxygen sensor or an optode in liquid media, usually water.It has particular significance in medicine and...
. Unlike the closely related Raynaud's phenomenon
Raynaud's phenomenon
In medicine, Raynaud's phenomenon is a vasospastic disorder causing discoloration of the fingers, toes, and occasionally other areas. This condition can also cause nails to become brittle with longitudinal ridges. Named for French physician Maurice Raynaud , the phenomenon is believed to be the...
, cyanosis is continually persistent. In addition, there is usually no associated trophic skin changes, localized pain, or ulcerations. Capillaroscopy and other laboratory methods may be helpful but only complement clinical diagnosis in unclear cases, especially when connective tissue disorders may be present.
Treatment
There is no standard medical or surgical treatment for acrocyanosis, and treatment, other than reassurance and avoidance of cold, is usually unnecessary. The patient is reassured that no serious illness is present. A sympathectomySympathectomy
A Sympathectomy is a procedure during which at least one sympathetic ganglion is removed.An example is endoscopic thoracic sympathectomy....
would alleviate the cyanosis by disrupting the fibers of the sympathetic nervous system
Sympathetic nervous system
The sympathetic nervous system is one of the three parts of the autonomic nervous system, along with the enteric and parasympathetic systems. Its general action is to mobilize the body's nervous system fight-or-flight response...
to the area. However, such an extreme procedure would rarely be appropriate. Treatment with vasoactive drugs is not recommended but traditionally is mentioned as optional. However, there is little, if any, empirical evidence that vasoactive drugs (α-adrenergic blocking agents
Alpha blocker
Alpha-1 blockers constitute a variety of drugs which block α1-adrenergic receptors in arteries and smooth muscles.-Pharmacology:...
or calcium channel blockers) are effective.
Prognosis
While there is no cure for acrocyanosis, patients otherwise have excellent prognosis. Unless acrocyanosis results from another condition (e.g. malignancy, antiphospholipid syndrome), there is no associated increased risk of disease or death, and there are no known complications. Aside from the discoloration, there are no other symptoms: no pain, and no loss of function. Patients can expect to lead normal lives. In secondary acrocyanosis treatment of the primary condition defines outcomes.Epidemiology
Although there is no definitive reporting on its incidenceIncidence (epidemiology)
Incidence is a measure of the risk of developing some new condition within a specified period of time. Although sometimes loosely expressed simply as the number of new cases during some time period, it is better expressed as a proportion or a rate with a denominator.Incidence proportion is the...
, acrocyanosis shows prevalence
Prevalence
In epidemiology, the prevalence of a health-related state in a statistical population is defined as the total number of cases of the risk factor in the population at a given time, or the total number of cases in the population, divided by the number of individuals in the population...
in children and young adults than in patients thirty years of age or older. Epidemiological
Epidemiology
Epidemiology is the study of health-event, health-characteristic, or health-determinant patterns in a population. It is the cornerstone method of public health research, and helps inform policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive...
data suggests that cold climate, outdoor occupation, and low body mass index
Body mass index
The body mass index , or Quetelet index, is a heuristic proxy for human body fat based on an individual's weight and height. BMI does not actually measure the percentage of body fat. It was invented between 1830 and 1850 by the Belgian polymath Adolphe Quetelet during the course of developing...
are significant risk
Risk
Risk is the potential that a chosen action or activity will lead to a loss . The notion implies that a choice having an influence on the outcome exists . Potential losses themselves may also be called "risks"...
factors for developing acrocyanosis. As expected, acrocyanosis would be more prevalent in women than in men due to differences in BMI. However, the incidence rate of acrocyanosis often decreases with increasing age, regardless of regional climate. It completely resolves in many women after menopause implying significant hormonal influences.
In the newborn
Acrocyanosis is common initially after delivery in the pretermPremature birth
In humans preterm birth refers to the birth of a baby of less than 37 weeks gestational age. The cause for preterm birth is in many situations elusive and unknown; many factors appear to be associated with the development of preterm birth, making the reduction of preterm birth a challenging...
and full term
Full Term
Full Term in the universities of Oxford and Cambridge refers to the eight weeks within the longer academic term during which lectures are given and students are required to be in residence...
newborn Intervention normally is not required, although hospitals opt to provide supplemental oxygen for precautionary measures.
See also
- Pernio (Chilblains)
- CyanosisCyanosisCyanosis is the appearance of a blue or purple coloration of the skin or mucous membranes due to the tissues near the skin surface being low on oxygen. The onset of cyanosis is 2.5 g/dL of deoxyhemoglobin. The bluish color is more readily apparent in those with high hemoglobin counts than it is...
- Peripheral artery occlusive diseasePeripheral artery occlusive diseasePeripheral vascular disease , commonly referred to as peripheral arterial disease or peripheral artery occlusive disease , refers to the obstruction of large arteries not within the coronary, aortic arch vasculature, or brain. PVD can result from atherosclerosis, inflammatory processes leading to...
- Raynaud's phenomenonRaynaud's phenomenonIn medicine, Raynaud's phenomenon is a vasospastic disorder causing discoloration of the fingers, toes, and occasionally other areas. This condition can also cause nails to become brittle with longitudinal ridges. Named for French physician Maurice Raynaud , the phenomenon is believed to be the...
External links
- Acrocyanosis. The Merck Manual.