The experience of pain in response to things that normally are not painful, such as light touching of the skin. Allodynia is associated with several underlying conditions. It can occur with fibromyalgia (a disorder that causes muscle and joint pain throughout the body), migraine headaches, peripheral neuropathy (damage to the nervous system caused by diabetes and other medical conditions) and postherpetic neuralgia (damage to the nerves due to infection by the virus that causes shingles).
Allodynia is caused by central sensitization, a condition in which an acute injury or a painful stimulus makes the nervous system highly reactive. Researchers believe that inflammatory cells surround the areas of tissue damage and produce cytokines and chemokines. These substances normally help regulate tissue healing, but they can also alter the nature of the neurons (nerve cells) that surround the area of injury, making them overly reactive.
Fortunately, many different medications are available to treat allodynia, depending on its underlying cause. For example, the doctor might prescribe lidocaine (brand name Xylocaine) or pregabalin (Lyrica) or recommend taking nonsteroidal anti-inflammatory drugs (NSAIDs) such as naproxen (Aleve). In the case of an underlying disorder such as diabetes, treating the disorder may also help alleviate the allodynia.