A fan-shaped pattern of small intradermal veins on the medial (inside) or lateral (outside) aspect of the ankle and foot is called corona phlebectatica, or corona phlebectasia. Corona implies that they "crown" the ankle.
Corona phlebectasia is thought to be an early sign af advanced venous reflux disease. This reflux typically originates at the saphenofemoral junction with venous blood refluxing into the great saphenous vein. Less commonly, saphenopopliteal reflux into the lesser (short) saphenous vein is the underlying cause of corona phlebectatsia.
Other names for corona phlebectasia include "malleolar flare" and "ankle flare". Once the venous reflux is treated with VNUS Closure or EVLT, then the corona is treated with lasers, and rarely sclerotherapy.