Do you feel pain lately when you brush your hair or change your clothes? Does your skin seem more sensitive than usual? Then you may be surprised to learn: pain during daily activities that are normally not uncomfortable may actually be a side effect of your migraine headache.
This often-overlooked symptom — known as allodynia — is, in fact, frequently found in people living with regular episodes of migraine.
Allodynia is a type of neuropathic pain caused by a garbled transfer of information within the central nervous system. Neuropathic pain is unlike the somatic pain we experience from a bee sting or toe stub; that is, pain which follows normal pathways to the brain. Rather, neuropathic pain results from damage or disturbance to the nervous system itself.
Typically, pain is meant to alert us when something is wrong with our body. However, in allodynia, the pain serves no purpose since it is caused by stimuli that should not ordinarily result in any pain. (Note: this differs from hyperalgesia, which stimulates a heightened pain sensation from normally painful stimuli.)
Allodynia can occur in nerve-related conditions such as migraine and fibromyalgia, and can also be present in patients with diabetes or shingles. There are three types:
Self-testing can help you determine if you have symptoms of allodynia:
Most patients describe their allodynia pain as a sharp, stinging or burning sensation.
If you feel pain or tingling at the test area, contact your doctor for further testing and an appropriate diagnosis.
Your physician will perform similar testing and also ask deeper-dive questions about your pain, including rating its level from 1 to 10 and asking you to describe the pain in detail. The doctor will also ask questions about your medical history and any medication you might be taking, and may also request blood tests, MRI or CT scans to determine if an underlying condition might be triggering the allodynia.
According to the Migraine in America Symptoms and Treatment (MAST) study, which involved 15,000 people in the US, 40% to 70% of people with migraine experience some type of allodynia during attacks. Its presence is more common in people with migraine than in those who experience tension headaches or other head pain.
When present in conjunction with migraine, allodynia may also cause more painful headaches, higher sensitivity to light and/or sound, changes in vision, and nausea. It usually dissipates when the migraine episode ends, although sometimes it persists afterwards.
In a migraine episode, nerve endings on blood vessels in the brain send pain signals through the central nervous system, resulting in a throbbing headache. If those signals do not receive acute treatment, the spinal cord and brainstem may continue to send their own signals, further prolonging the sensation of pain.
This process of pain signaling can lead to hyper-sensitization and, consequently, even normal stimuli can begin to generate sensations of pain. Although allodynia may feel like it’s coming from the skin, the pain is the result of those mixed signals within the nervous system.
You are more likely to experience allodynia if you have chronic migraine or have had migraine for years, if you get severe symptoms during migraine attacks, or if you experience migraine with aura. According to Dr. David Dodick, researcher in the MAST study, the presence of allodynia indicates the severity of the migraine attack, and predicts the likelihood that episodic migraine may progress to chronic (15+ migraine attacks per month).
40% to 70% of people with migraine experience some type of allodynia during attacks. Its presence is more common in people with migraine than in those who experience tension headaches or other head pain.
Besides migraine, other injuries, diseases or conditions can disrupt the central nervous system and increase the risk of allodynia, including fibromyalgia, diabetes, shingles, chemotherapy, minor trauma (muscle and bone-related), and even poor diet (particularly vitamin deficiency).
Individuals with depression and anxiety are also 83% more likely to experience allodynia. So are people who over-medicate on over-the-counter painkillers or opioids, as these medications impact the pain pathways in the nervous system.
Migraine and allodynia also share certain risk factors — for example, obesity and smoking are associated with both allodynia and chronic migraine onset. And females are at higher risk of both allodynia and migraine due to monthly hormonal shifts.
Painkillers, both oral and topical, can help relieve allodynia, or a physician may choose to administer a shot of a non-steroidal anti-inflammatory drug (NSAID) to alleviate the pain.
Other treatment options may include the use of CBT products or of physical therapy, focused on desensitization of the nervous system. In rare extreme cases, deep nerve or spinal cord stimulation, nerve blockers, or even surgery may be considered.
Medical professionals typically try to diagnose and treat an underlying health condition, such as migraine, rather than simply treating allodynia itself. However, migraine medications like triptans are less effective once allodynia is already underway, so prevention can be key.
The best way to avert allodynia that comes with a migraine is to begin acute treatment at the first sign of the migraine episode. Early treatment can also decrease the risk that the presence of allodynia may cause episodic migraine to worsen into chronic migraine.
Another approach to preventing allodynia is to avoid migraine attacks in the first place. Preventive migraine medication can be prescribed for people with frequent and/or severe migraine.
Prevention can be helped by leading a healthy lifestyle with a balanced diet and regular exercise, to maintain a healthy weight and avoid vitamin deficiencies. Avoid fasting or dehydration, as these can increase the frequency of migraine headache.
If you’re at risk of developing allodynia, know your medical history and have regular check-ups. If you experience allodynia symptoms, reach out to your physician. The longer allodynia goes untreated, the more frequent and severe your migraine symptoms may become, increasing your risk of developing chronic migraine. Early diagnosis of both migraine and related allodynia makes treatment of each easier and more effective.
Everyone’s experience with migraine is unique to them. Mable’s worldwide team of leading migraine experts focuses on bringing you positive change, with effective, individualized treatments tailored to alleviate your specific symptoms, decrease your headache frequency, and return you to the lifestyle you love.