| Spider angioma | |
|---|---|
| Other names | Nevus araneus, spider nevus, vascular spider, spider telangiectasia[1] |
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| Non-benign angiomas indicatingcirrhosis | |
| Specialty | Dermatology  |
Aspider angioma orspider naevus (plural: spider naevi), alsonevus araneus, is a type oftelangiectasis[2] (swollen, spider-like blood vessels on the skin) found slightly beneath the skin's surface, often containing a central red spot and deep reddish extensions (seeBlood color) which radiate outwards like aspider's web or aspider's legs. They are common and oftenbenign, presenting in around 10–15% of healthy adults and young children.[3] However, having more than three spider angiomas is likely to be abnormal and may be a sign ofliver disease and/orhepatitis C (HCV virus);[4] it also suggests the probability ofesophageal varices.[5]
Spider angiomas are found only in the distribution of thesuperior vena cava, and are thus commonly found on theface,neck, upper part of thetorso, andarms.[citation needed]
Spider angiomas form due to failure of thesphincteric muscle surrounding acutaneousarteriole. The central red dot is the dilated arteriole and the red "spider legs" are small capillaries carrying away the freely flowing blood. If momentary pressure is applied, it is possible to see the emptied capillaries refilling from the center. No otherangiomas show this phenomenon.[7]
The dilation, in turn, is caused by increasedestrogen levels in the blood. Manypregnant women and women usinghormonal contraception have spider angiomas, which is due to high estrogen levels in their blood. Individuals with significantliver disease also show many spider angiomas, as their liver cannot metabolize circulating estrogens, specificallyestrone, which derives from the androgenandrostenedione.[3] About 33% of patients withcirrhosis have spider angiomas.[8]
Spider angiomas (spider-like blood vessels on the skin) are one of the main symptoms caused by aHCV infection. Discovering an infected patient with hepatitis C early on in the infection phase increases the chances of the virus being successfully treated and cured by oral medication.[4]
Diagnosis is byclinical examination. Spider naevi are most commonly seen bygeneral practitioners, ordermatologists. Whilst alesion can be identified as a spider naevus, this is not adiagnosis in itself. The clinical picture should be indicative of whether there is underlying disease that should be investigated.[citation needed]
Spider angiomas areasymptomatic and usually resolve spontaneously. This is common in the case of children, although they may take several years to disappear. If the spider angiomas are associated with pregnancy, they may resolve after childbirth. In women taking oral contraceptives, they may resolve after stopping these contraceptives.[citation needed]
For spider angiomas on the face, techniques such aselectrodesiccation andlaser treatment can be used to remove the lesion.[9] There is a small risk of ascar; however, it usually leaves nothing.