Allodynia is pain which occurs in response to a stimulus which is usually not painful. In a simple example of allodynia, a patient might complain of pain after being gently brushed with a hand or a few fingers. This heightened sensitivity to touch is often associated with neurological conditions and chronic pain conditions, including neuropathies, fibromyalgia, and migraines. For patients, it can be extremely frustrating.
Tactile allodynia occurs in response to tactile stimuli, which can include things like the weight of a shirt, a breeze, a handshake, and so forth. These stimuli are generally not considered to be painful, and they do not cause injury to the body, but the body screams “pain” as it interprets these stimuli. Thermal allodynia is an extreme sensitivity to temperature changes. Again, the variations in temperature are not enough to cause damage to the body, but they are interpreted as painful.
This condition is believed to be caused by confused messages among the cells which interpret sensation. Painful sensations are usually interpreted by nocireceptors, and for some reason, these cells become involved when normally information about these sensations would be sent by different cells. The nocireceptors tell the brain that something injurious is being experienced, and the brain interprets this as pain. When something damaging actually is occurring, this response is desired, as it acts as a signal to address the harmful stimulus. In the case of allodynia, however, the pain signals serve no function.
This condition can be challenging to treat. Patients with pain conditions sometimes have trouble finding a doctor who recognizes their condition and who can take the time to perform testing to learn more about what may be going on to cause the heightened sensitivity to touch. Unfortunately, patients with pain conditions are sometimes accused of being drug seekers, and they may face denial of insurance benefits and other problems as they attempt to manage their conditions.
Since the cause of allodynia often cannot be cured, treatment focuses on managing it. Analgesic medications are used to dull the pain, with the dosages periodically being adjusted as the patient develops a tolerance to these medications. Once a cause is identified, medications may also be administered to manage the cause. Curiously, there are a number of neurological conditions which can be recognized and diagnosed, with medications available to treat these conditions, but doctors do not actually understand how these medications work in the body. This illustrates how much the scientific and medical community has to learn about the human body.