Scelotherapy for upper leg spider veins: what are the typical cons in this approach for the patient?

Few cons: Sclerotherapy is typically used alone provided you don't have underlying superficial venous insufficiency. That is determined by an ultrasound. Cons are some increased pigmentation in the treated area occasionally . A rare complication is a small sore at injection site( less than 1% in hands of skilled practitioner). I would advise you to see a board certified phlebologist(vein doctor).

Not many: I agree with dr. Oren, there can be some temporary pigmentation over the treated veins. It is possible, but rare, to be allergic to the chemical used for treatment. A small sore can also develop at the injection site. Blood clots have occurred but they are also quite rare. For the most part, you can expect some temporary bruising, stinging, and discomfort but little else.

Sclerotherapy Veins: Sclerotherapy for spider veins of the legs is a very common cosmetic treatment to remove spider veins from the legs and is very effective. Typical cons to sclerotherapy is that there is a small risk of allergic reactions to the medications, & that there is some risk of skin reactions such as hemosiderin staining of the skin or matting of the skin (discoloration). These resolve in most patients.

Ulceration: In rare instances you could also get a skin ulceration.