Skin necrosis, a side effect of cold therapy machines, occurs when the skin dies after prolonged exposure to cold temperatures. Although these machines are advertised for “continuous cold therapy” for up to 11 hours, using them for more than 20-30 minutes at temperatures below 59º F is associated with a risk of skin damage, nerve damage, skin necrosis, and other complications.
Overview: Skin Necrosis
Skin necrosis occurs when a large number of cells in the skin die. It may affect only the epidermis (uppermost layers of skin), or extend into the dermis (deeper layers of skin) and subcutaneous tissues. In the most severe cases, skin necrosis also involves necrosis of nerves, muscles, tissues, ligaments, and more.
Necrotic skin cannot be healed and is highly susceptible to bacterial infection. Therefore, standard treatment is debridement (surgical removal of the skin) followed by grafting of healthy skin from another area of the body.
Cold Therapy and Skin Necrosis
High-volume cold therapy machines are advertised as superior to traditional ice-packs because they can provide up to 11 hours of “continuous cold therapy.” The machines pump freezing-cold water into a compression pad attached to a patient’s body.
It may seem counter-intuitive, but skin necrosis from cold therapy can occur above freezing temperatures. The beneficial effects of cold therapy end at about 15ºC (59ºF) — below those temperatures, there is an increased risk of injury. Furthermore, skin damage is more likely to occur from prolonged cooling than quick cooling (with an ice pack, for example, which is typically removed every 10 minutes to allow the skin to re-warm while deeper tissues stay cold). Over time, slow cooling can cause intra- and extracellular shifts in protein and ion levels, which may cause extensive tissue damage, skin damage, nerve damage, skin necrosis, and more.
Case Report of Skin Necrosis from Cold Therapy
One of the most vivid depictions of the dangers of skin necrosis from cold therapy was published in January 2007, in Orthopedics, in a study titled: Severe Frostbite of the Knees After Cryotherapy (GRAPHIC).
To avoid cold therapy complications like skin necrosis and frostbite, the surgeons recommended:
“Current recommendations for cryotherapy include 20-30 minutes of cryotherapy with a maximum time of 40 minutes, always with a protective covering (usually a towel) between the cryotherapy wrap and the skin. The cycle can be repeated every 2 hours while the patient is awake.”