Any foreign body or device that is introduced in the body will create an inflammatory reaction. This is the way our immune system protects us from anything that it does not recognize. Liquid silicone is not an exception to this rule. Silicone injection can create inflammatory nidus, sinuses or fistulas, and granulomas that can be extremely painful. When silicone is injected in the buttock, breasts, or any part of the body, a cell called a macrophage interacts with the silicone starting an inflammatory response. This chronic inflammation results in a mass of chronically inflamed tissue with very specific microscopic characteristics. This inflammation, not only occurs locally, but because liquid silicone is known to migrate,it can affect other parts of the body. The results are hardening of the tissue that can be asymptomatic to the very painful and deformed tissue. It is interesting to see that liquid silicone relays in this chronic reaction in order to avoid migration and contain itself. I am sure you have heard about people who have died after the injection of an unauthorized product in the buttock area. Silicone has been linked to acute thrombosis of vessels (clotting of vessels) and although the mechanism of action is not fully understood, the coagulation system has been shown to be activated leading to lung hemorrhages. Remember we are talking about the lungs and other parts of the body affected even though the injections were not in the lung itself. Once again the definition of inert (See Part 1 of silicone blog) seems to be too general and on a chemical level, but in practice there is some level of response to liquid silicone that can manifest serious complications that are hard to fix surgically or that can significantly compromise an organ to the extreme of causing death. I will discuss in the next blog the current FDA approved liquid silicone and its indications.