What Pain Patients Can Do to Relieve Their Itching
Pain is hard enough to deal with but when it's accompanied by constant itching—sometimes as a pain medication side effect—the situation can be unbearable. Here's what can be done to quell the itch.
Some patients suffer from neuropathic itch, a kind of chronic itch caused by the malfunction of nerve cells. It appears in many of the same conditions that can cause chronic nerve pain, such as shingles. Other conditions that can cause neuropathic itch include spinal cord lesions, phantom limb syndrome, and brain tumors.
Treating pain-related itching often requires a team effort by a neurologist and dermatologist, according to Wolfgang Liedtke, MD, PhD, Professor in the Departments of Neurology, Anesthesiology and Neurobiology at the Duke University Center for Translational Neuroscience in Durham, North Carolina.
“Patients scratch so badly they end up with wounds,” says Dr. Liedtke, who recently published a study on a potential new drug target for itching. “The wound doesn’t heal well because the nerve is injured, and then they can end up with an infection. This is especially a risk in diabetic patients. They can end up with a chronically infected wound on top of an injured nerve.”
Treating Pain-Related Itching
The most common type of itching, such as from a mosquito bite or hives, occurs when skin cells and cells in the vicinity of the lesion, such as immune cells, release a chemical called histamine. This type of itching is usually treated with antihistamine pills or creams.
Antihistamines are not effective in treating itching associated with chronic pain, said Dr. Liedtke, who treats patients with head and face pain and also associated itch in a considerable number of these patients.
It isn’t always easy to find a dermatologist who is knowledgeable about treating pain-related itching, Dr. Liedtke says. “Patients have to find someone who won’t just say, ‘This is a nerve injury, which I can't treat.’ Successful treatment requires a dermatologist and neurologist working together to treat both the pain and itching.”
The first step often is topical treatment for itching with corticosteroid creams, antibacterials or local anesthetics.
The next step may be treatment for nerve pain, which can involve medications such as Lyrica (pregabalin) or Neurontin (gabapentin), together with an antidepressant or nerve block applied to the injured nerve.
In addition, behavior treatments with a psychologist can be helpful to teach patients to stop constantly thinking about the itching. The psychologist may suggest how to avoid itch triggers, provide training in relaxation techniques, and teach patients how to monitor and reduce their scratching.
Opioid-Induced Itching Especially Hard to Treat
A particularly difficult problem to treat is opioid-induced itching. Itching is one of the most prevalent side effects of painkillers such as morphine and oxycodone. Dr. Liedtke says opioid-induced itching is not responsive to antihistamine treatments. He has had some success in treating the problem with capsaicin, derived from hot peppers. Capsaicin can desensitize nerves.
“With the increase in opioid addiction, we are seeing more opioid-induced itch,” Dr. Liedtke notes. “The itch is quite intense. If we are able to wean a patient off opioids, the itch goes away. We’ve seen that itch can be a considerable incentive to stop taking opioids.”