The Lesion with Legs

DISCUSSION
Spider angiomas (SAs), originally called nevus araneus, are actually neither angiomas nor nevi. Instead, they are telangiectasias formed from a superficial arteriole whose surrounding sphincter muscle has failed. The “legs” are tiny veins that carry blood away from the central lesion; this is why they blanch so readily with central pressure and refill from the center outward.

SAs affect 10% to 15% of children and occur only in areas along the path of the superior vena cava. Besides the face, they can be found on the trunk, arms, and dorsal hands.

When solitary, these lesions are benign and can be either left to clear on their own or removed by laser or electrodessication. The presence of three or more lesions warrants further investigation, since multiple SAs can signify underlying disease (eg, cirrhosis of the liver, thyrotoxicosis, or systemic sclerosis).

This patient was not inclined to let us treat the lesion; within a few years, a teasing comment from a classmate or two may change his mind! But with a little luck, it will disappear on its own eventually.

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TAKE-HOME LEARNING POINTS

• Spider angiomas (SAs) are actually dilated telangiectatic arterioles manifesting as blanchable, bright red, pinpoint papules with venous “legs” that extend from the center.
• SAs affect 10% to 15% of all children and are confined to areas drained by the superior vena cava.
• Pressure on the lesion with a glass slide (a process called diascopy) causes total blanching; this, along with the clinical findings, confirms the diagnosis.
• Most SAs resolve on their own eventually, but they can be destroyed by laser or electrodessication.
• The presence of more than three SAs should prompt a search for potential causes, such as liver disease, thyrotoxicosis, or systemic sclerosis.