A spider angioma or spider nevus is a common vascular lesion, a type of telangiectasia (swollen blood vessels) beneath the skin surface. It is characterized by central red arteriole, or punctum, representing the body of the spider, surrounded by a radial pattern of thin-walled capillaries, resembling legs.
The lesion is also known as a nevus araneus, spider nevus, vascular spider, and spider telangiectasis.
It is present in 10-15% of healthy adults and young children as solitary or multiple lesions ranging in size from 1-10 mm. Liver disease, estrogen therapy, and thyrotoxicosis should be considered especially when the lesions are multiple.
In adults, these are most frequently found on exposed areas of the body, such as the face, neck, upper trunk (above the nipple line), and arms. In children, the back of the hands and fingers are commonly affected.
Spider angiomas are more common in women than in men, especially in women of childbearing age due to pregnancy or oral contraceptive use.
Pathophysiology of Spider Angioma
Spider angiomas occur as a result of the dilation of preexisting vessels. It is not a vascular proliferation. That means new vessels are not formed, only preexisting vessels dilate.
Most of these angiomas are seen in a healthy person. Association with thyrotoxicosis, estrogen-excess states [ pregnancy, oral contraceptive use] and liver disease is known.
In liver disease, spider angiomas are large, multiple and occur in an atypical location. Other findings suggestive of liver disease may be found, including palmar erythema, muscle atrophy, gynecomastia, ascites, jaundice, splenomegaly etc.
The exact cause of the spider nevus is not clear. States of estrogen-excess such as pregnancy and liver disease have been associated with spider angiomas.
Exposure to sun and injuries also have been implicated as factors.
The hormone has supposedly dilating effects on endometrial spiral arterioles during pregnancy. Additional biologic substances including vascular endothelial growth factor, basic fibroblastic growth factor, substance P, and endogenous vasodilators have also been implicated in the pathogenesis of spider angioma.
Multiple spider nevi are found more commonly in alcoholic cirrhotics.
Spider angioma is asymptomatic and acquired. It occurs most commonly in exposed areas of the skin, including the face, neck, upper trunk, and arms in adults. In children, lesions are common on the fingers and hands.
Patients with liver disease may exhibit multiple prominent lesions over the trunk and face, as shown in the image below.
When a lesion is detected, enquire about
- Alcohol abuse
- Drug intake causing liver damage
- Pregnancy, hormonal supplements, or oral contraceptive use in females
On examination, spider angiomas are red with a small central arteriole, or punctum which is surrounded by thin-walled vessels in a stellate pattern. Sometimes, only the punctum is seen.
The lesion usually measures 1-10 mm in diameter.
When pressure is applied with a slide, it causes blanching and temporary obliteration of the lesion. On release of pressure, it quickly refills.
Occasionally, pulsation of the punctum may be noted.
In case there is doubt, pregnancy should be ruled out or established.
Perform a comprehensive abdominal examination with special attention to the liver and spleen. Examine patients for stigmata of liver disease, including ascites, palmar erythema, change in body fat and hair distribution, muscle and gonadal atrophy, splenomegaly, and leukonychia.
- Acneiform Eruptions
- Angioma Serpiginosum
- Basal Cell Carcinoma
- Cherry Hemangioma
- Generalized Essential Telangiectasia
- Hereditary Benign Telangiectasia
- Unilateral Nevoid Telangiectasia
- Insect Bites
- Osler-Weber-Rendu Syndrome
- Costal fringe – a bandlike pattern of venous telangiectases along the anterolateral costal margins
Patients with extensive spider angioma lesions should be investigated for underlying liver disease or pregnancy, as applicable.
In doubtful diagnosis, consider skin biopsy to exclude basal cell carcinoma or other conditions.
Spider angiomas in children may resolve in some while in others become permanent.
Spider nevi associated with pregnancy resolve spontaneously 2-9 months after the birth of a child or after discontinuing oral contraceptives.
Lesions associated with the liver disease may improve upon treatment of the underlying condition. Regression after liver transplantation in liver failure has been noted.
Rarely following have been used to treat the nevus when there is a cosmetic concern.
- fine-needle electrocautery,
- Pulsed dye laser
- KTP or potassium-titanyl-phosphate laser
There is a risk of the small scar with these procedures and spider angiomas can recur after treatment.