By Foot and Ankle Specialists of Marin, Feb 19 2016 08:52PM
The third condition we see in the winter is something I like to classify as cold induced tissue trauma. This can be from extreme frostbite, which is uncommon in Marin County, to chilblains (pernio), to Raynauds Syndrome. Frostbite and Chilblains is from overexposure to cold for a prolonged period of time and can lead to very serious tissue loss.
Raynaud's Syndrome is a cold induced vasospasm of the small arteries that go to our fingers and toes. Several patients a year come to our office with the complaint of color changes or wounds on the tips of their toes. Unlike overexposure to cold, Raynaud’s happens when the temperatures drop, but the patient is wearing shoes, socks and warm clothing. Patients often notice color changes first in their fingers. The fingertips around the nail, or up to the first or second knuckle will turn white. This can last for several minutes. Then the fingers turn bright red followed by a bluish/purple color. The physiology behind this is what is called a vasospasm. As the blood leaves our core, it cools as it moves into our arms and legs. The cold blood and cold temperatures can cause the arteries to spasm in some people. As this happens the blood vessels clamp down, and less blood flows to the skin and the skin blanches and turns white. As metabolites build up in your tissues, mainly nitric oxide, the blood vessels dilate. Sometimes they dilate so much that you get a rush of blood back into the body part and the skin turns bright red. As the blood rushes in, the venous system gets overloaded and venous congestion develops causing the tissues to turn blue. The problems arise during the blanching phase of Raynaud's. As the tissues are “starved of blood,” inside of that harsh shoe and sock environment, tissue damage begins to occur from rubbing and friction. The longer the vasospasm, the higher the risk of worsening tissue damage. Patients often come in with wounds on the plantar fat pads of their toes with no known cause of trauma. The surrounding skin will have a mottled red, purple appearance. With a careful history, the patient will describe color changes they have noticed in their fingers, which goes unnoticed in their feet in closed shoes.
Treatment for Raynaud’s Syndrome is tailored first to prevention. Keeping your extremities warm is the key. Not only hands and feet, but arms and legs. I tell my patients you need to wear long underwear, long Johns or leggings to keep the blood warm as it moves from your trunk to your feet. The same goes for the upper extremity. You need to insulate those arms and legs and protect from the cold. Patients with severe Raynaud’s often have vasospasms even in warm weather. Patients that have severe Raynaud’s are often treated with oral nifedipine, a vasodilator used to treat high blood pressure. The effect of nifedipine, helps prevent the arteries from spasming. It is very important to treat any wounds that form from the tissue trauma. This can be as simple as covering the wound with a topical antibiotic and a large sterile dressing, to more advanced wound care techniques which we perform at Foot and Ankle Specialist of Marin.
So to recap. Keep your feet clean and warm, but dry, all Winter long, and remember… Spring is coming.
Dr. Anthony Fedrigo