Are there side effects to sclerotherapy?

Red, raised areas at the sites of injection. These are similar to hives and the response should disappear within a day or so.

Brown lines or spots on the skin at the sites of treated blood vessels. Darkened areas may result when blood escapes from treated veins and are probably formed from iron in the blood. These dark areas occur more often in patients who have larger veins treated or those patients that tan easily. In most cases, they disappear within a year, but they may last longer.

Development of groups of fine red blood vessels near the sites of injection of larger vessels. About one-third of patients develop groups of vessels especially on the thighs. Most disappear by themselves, some need additional injection treatments or laser therapy, a few may last.

Small, painful ulcers at treatment sites either immediately or within a few days of injection. These occur when some of the solution escapes into the surrounding skin or enters a small artery at the treatment site and can be successfully treated, but it is necessary to inform the dermatologist immediately.

Temporary bruises. Bruises usually occur after laser treatments and are probably related to the thinness of blood vessel walls. They usually disappear in a few weeks. Occasionally, bruising is seen with sclerotherapy.

Allergic reactions to sclerosing solutions. Although such reactions are uncommon, they can be treated. Inform your dermatologist immediately.

Inflammation of treated blood vessels. This is very unusual but when it occurs, it is treated with medications such as aspirin, compression, antibiotics, or heat.

Lumps in injected vessels. This is coagulated blood and is not dangerous. The dermatologist may drain the blood from these areas a few weeks after injection.
Burning with discoloration of the skin.