What is spider nevus?
Spider nevus goes by several names:
- spider veins
- spider angioma
- nevus araneus
- vascular spider
A spider nevus is a collection of small, dilated arterioles
(blood vessels) clustered very close to the surface of the skin. The cluster of
vessels is web-like, with a central spot and radiating vessels.
Spider nevi (plural) can be caused by injuries, sun exposure,
hormonal changes, or liver disease, but often the cause is unknown. For most
people, the nevi are not a medical concern. In some cases, they cause discomfort.
The vessel clusters can be treated or removed in a number of ways, which
include the use of compression stockings, chemical injections, and laser
What are the symptoms of spider nevus?
For most people with spider nevus, the only symptom is the
appearance of the vessel cluster. There may be a red dot in the center of a
cluster of thin vessels, but this is not always the case. The thin vessels form
a web-like shape and are red, blue, or purple in color. When you apply
pressure, they will disappear and then reappear because blood is flowing back
into the vessels.
Spider nevi can occur anywhere on the body, but are most
common on the face, neck, and legs (sun-exposed areas). Some people may
experience aching or burning in the area of the vessel cluster. This pain
occurs most commonly when the vessels are in the legs, and after a long period
Spider nevi are usually not cause for concern if you don’t
have any other symptoms or health conditions.
When to see a doctor
If you have a spider nevus and feel weak, unusually tired, or
bloated, or if your skin or eyes appear yellow, you should see your doctor. You
should also see your doctor if you have multiple clusters of spider vessels, to
find out if you have underlying liver problems. If you do not have any symptoms
of illness, you can wait until your regular checkup to show the nevus to your
What causes spider nevus?
The webs of small arterioles and capillaries that appear close
to the skin are abnormal.
What causes this to happen is not entirely understood.
Researchers believe that various factors may result in spider nevi. These
- exposure to the sun
- changes in hormone levels
- underlying illnesses, such as liver disease
Spider nevi, especially if there is more than one, is a common
sign of liver disease. People with liver disease often have multiple vessel
clusters at a time.
Spider nevus commonly occurs when you have a lot of estrogen
in your system, as is the case with chronic liver disease or during pregnancy.
Spider nevus is more common in people with alcohol-related liver cirrhosis
(liver disease) than in those with cirrhosis not related to alcohol.
What are the risk factors for spider nevus?
Although the causes of spider nevus are not fully understood,
several factors put you at a higher risk:
- Age: The older you are, the more likely you
are to get spider nevi. Aging may cause the valves in your blood vessels to
- Hormonal changes: Going through puberty,
pregnancy, and menopause, as well as taking hormonal contraceptives, may lead
to spider nevi.
- Sun exposure: Being in the sun, especially if
you are fair-skinned, can cause spider nevi to form on your face.
- Family history: Weak vessel valves may run
in families, so if members of your family have spider nevi, you are more likely
to get them as well.
- Obesity: Excess weight can put pressure on your
- Sitting or standing for long periods of time: Being
immobile can prevent the healthy circulation of blood.
How is spider nevus diagnosed?
Your doctor will most likely be able to tell you if you have
spider nevi simply by looking at the appearance of the skin in question.
Sometimes a skin biopsy may need to be performed to confirm the diagnosis. What
is more important, however, is diagnosing the underlying cause and ruling out
certain conditions that may have produced the vessel clusters.
You will be asked about hormone supplements and any other
medications you are taking. Your doctor will also ask you about alcohol
consumption because alcohol abuse can lead to liver disease. Spider nevi may be
a sign of liver disease. If liver problems are suspected, your doctor may draw
a sample of your blood to be tested.
The liver is responsible for many important tasks, such as
detoxifying the blood, helping to digest food, and producing proteins that help
the blood to clot. Liver disease testing, also called a liver panel, involves
taking blood samples to test for the enzymes and proteins produced and excreted
by the liver. Increased or decreased levels of these substances, as well as the
presence of certain types, can signal liver disease.
What are the treatments for spider nevus?
In many cases, there is no need for spider nevi to be treated.
If they are not causing uncomfortable burning or itching and are not related to
liver disease, then spider vessels are not harmful. If, however, they cause
discomfort, or if you choose to have them treated for cosmetic purposes, you
have several choices.
Lasers aimed at the spider nevus can eventually cause it to
fade and disappear. The laser and the heat it emits may cause some pain or
discomfort, but this should go away as soon as the laser is removed. Two to
five treatments are typically needed to completely fade the spider nevus.
How can spider nevus be prevented?
You may not be able to prevent spider nevus entirely. If you
are predisposed to this condition due to family history and genetics, you’re
likely to get spider nevi no matter what you do. While no specific preventive
measures are known, you may prevent new spider nevi from forming by:
- avoiding hormone therapy
- wearing sunscreen on those areas most commonly
affected, including the face, neck, and legs
- controlling your alcohol consumption
- treating liver disease if present