What Is Allodynia?
Migraine headaches cause intense, throbbing head pain. These headaches can also make your nerves extremely sensitive, and even the slightest touch may become painful. This is called allodynia, which means "other pain." Up to about 80% of people with this condition have allodynia during an attack.
Pain is an uncomfortable sensation, but it's meant to be helpful. It warns your body that you're injured so you can stop doing whatever caused it and treat it if needed. However, allodynia is pain that doesn't serve any purpose.
You also can have allodynia if you have a disease that damages your nerves, such as diabetes, or if you've broken a bone or have nerve damage from an injury.
Allodynia vs. hyperalgesia
Unlike allodynia, which causes you to feel pain when you shouldn't, hyperalgesia heightens the amount of pain you feel in a situation when you normally would. If you have hyperalgesia, things that would normally hurt a little can suddenly feel extremely painful.
Both symptoms can be caused by similar conditions, including migraines, diabetes, multiple sclerosis, certain cancers, shingles, and injuries from broken bones, nerve damage, and muscle strains.
Allodynia Symptoms
There are three kinds of allodynia:
Static allodynia or tactile allodynia is pain from the pressure of something against your skin. If you have this type, your skin hurts to touch when you put on a shirt, wear glasses, or put your head on a pillow.
Dynamic allodynia is pain that starts when something rubs lightly against your skin. Things such as the touch of a person's hand, running a brush through your hair, or water falling on your head in the shower can trigger it.
Thermal allodynia is pain that comes on in hot or cold temperatures. For instance, breathing in cold air can cause it.
Allodynia pain, which ranges from mild to severe, is different for each person.
Allodynia Causes
If you have frequent migraine headaches, allodynia can be a side effect.
A migraine is more than just a headache. It is a complex condition with the headache being just one symptom. During a migraine, your brain releases chemicals that cause the nerve endings around the brain to send signals to your central nervous system, which can result in the throbbing head pain you feel.
When those signals keep firing for an hour or so, your nerves become hypersensitive. Even normal signals, such as a touch on your scalp or face, can be very painful.
You're more likely to get allodynia if you:
- Get visual auras (zigzag lines or flashes of light) with your migraine headaches
- Have more than 15 headaches a month
- Have severe migraine headaches
- Have had migraine headaches for many years
You're also more likely to get allodynia if you:
- Have another pain condition, such as irritable bowel syndrome, chronic fatigue syndrome, or fibromyalgia
- Have depression or anxiety
- Have diabetes-related neuropathy
- Were assigned female at birth
- Are overweight or obese
- Have multiple sclerosis (MS)
- Have shingles
- Smoke
Allodynia Diagnosis
A neurologist is a doctor who specializes in problems with your brain, spinal cord, and nerves. If you have allodynia, a neurologist can help you figure out what's going on. They'll ask about your headaches, sensitivity to touch, and other symptoms. You'll also have a physical exam.
They may suggest one or more of these tests to get more information:
- Blood tests: Usually not needed unless another condition is suspected
- MRI: Usually not needed unless something else is suspected
Allodynia Treatment
If your allodynia is related to migraine, you can limit your symptoms by treating migraine symptoms as soon as they start. Some migraine drugs, including triptans, typically don't work for people who have allodynia. Instead, your doctor may give you a shot of a nonsteroidal anti-inflammatory drug (NSAID) called ketorolac or an ergot medication called dihydroergotamine.
You can also ask your doctor if you should take medicine to prevent migraine headaches, such as:
- Blood pressure drugs such as beta-blockers
- Antidepressants
- Anti-seizure drugs
Once your headache goes away, the allodynia usually eases up. But some people still have the pain even after the migraine is gone.
Migraine prevention
There are also some devices that can short-circuit the electrical activity in your brain that triggers a migraine, helping to prevent or stop it:
- SpringTMS or eNeura sTMS
- Cefaly
- gammaCore
Another way to avoid migraines is to have healthy routines. Exercise, get good regular sleep, and practice relaxation techniques such as yoga, tai chi, or deep breathing to ease stress.
Fasting and dehydration can both set off migraine headaches. So, don't wait too long between meals, and make sure you drink enough water during the day.
Takeaways
Allodynia is a symptom that causes you to feel pain when you shouldn't. Even light touch may cause you severe pain. Migraines can trigger allodynia, as can other conditions such as shingles, fibromyalgia, diabetes-related neuropathy, or even an injury. If your symptoms aren't getting better, talk with your health care provider to figure out what's causing your allodynia so you can find the right treatment for you.
Allodynia FAQs
How long does allodynia last?
How long allodynia lasts varies. If the symptom was triggered by a migraine, it may get better on its own. Other times, allodynia may last months or years. In this case, you may need specific treatment to treat its cause.
What deficiency causes allodynia?
A deficiency of vitamin B or D can cause allodynia. Your doctor will do blood work and a full physical to figure out what's causing your symptoms.
Who is more susceptible to allodynia?
People who have diabetes neuropathy, multiple sclerosis, or shingles are more likely to have allodynia. Women and those assigned female at birth are more prone to migraines, which can cause allodynia.
