On occasion they can be associated with an underlying condition such as venous insufficiency or tarsal tunnel syndrome, so if you have associated pain or swelling I would advise evaluation by your health care provider.
Telangectasias are usually more noticeable as we mature, are more common in women, and are aggravated by pregnancy and prolonged standing.
As a preventive measure, women can try compression hose. Supportive footwear and orthotics can also be helpful, as they reduce abnormal biomechanical forces at the inside of the ankle.
Treatment of these spider veins at the ankle is rarely required, but injection of the veins (sclerotherapy) or laser treatment is sometimes performed for cosmetic reasons.