What Are Allodynia And Hyperalgesia? A Painful Reality

This post was originally posted on Blogger August 1, 2024.

What Are Allodynia and Hyperalgesia? A Painful Reality

As someone living with neuropathic chronic pain, I also experience two, also debilitating, conditions known as Allodynia (pain from stimuli that does not usually cause pain) and Hyperalgesia (an extreme reaction to a stimulus that causes more severe pain than it should). 

These 2 types of nerve pains are often associated with conditions like diabetes, migraines, shingles, fibromyalgia, multiple sclerosis (MS), and complex regional pain syndrome (CRPS), which is my case. It can also be caused by a deep cut or amputation that affects nerve function. Also trauma from a stroke, certain treatments like radiation and chemotherapy, and other causes of nerve damage, can cause it. 

Both Allodynia and Hyperalgesia are known as Hyperesthesias, which are symptoms that involve extreme sensitivity in your sense of touch to both normally painful and not painful stimuli. The word Hyperalgesia comes from the Greek words “hyper”, which means “over”, and “aesthesis”, which means feeling, and medical professionals use this term to refer to sensations in which a person feels through their skin. An example of Hyperesthesia is feeling unusually strong temperature sensations when exposed to mildly warm or mildly cool temperatures. It makes it feel like it’s either scalding hot, or as cold as dry ice. It also makes a light touch feel like it is burning and sharp, and lingering.

Allodynia is rare, but current research suggests that up to 1 in 2 people with neuropathic pain experience Allodynia. Howard Hughes is thought to have had Allodynia in his later years; he seldom bathed, wore clothes, or cut his nails and hair, possibly due to the pain these typically normal actions would cause him.

Allodynia occurs when normally harmless stimuli become intensely painful. My skin is hypersensitive to touch, pressure, and temperature. Even the gentlest touch can feel like a searing sensation that lingers for hours. This can be triggered by seemingly innocuous activities like brushing up against something, someone gently touching my leg as a comforting gesture, getting dressed and undressed, having a shower, or simply being touched by a pet.

For me, the most affected areas are my legs. Everyday tasks like walking, sitting, or even sleeping can be excruciating due to the constant barrage of pain that these things cause with movement. These painful sensations are felt in addition to my already overwhelming CRPS pain signals. The slightest pressure from clothing, bed sheets, or even the air can feel like a thousand needles piercing my skin.

There are three main types of allodynia: dynamic, tactile, and thermal. I experience all three in my legs, which can make routine self-care activities incredibly challenging. A simple shower is traumatizing and a torturous ordeal, with the water both scalding and freezing my skin, as well as the pain from the water coming into contact with my skin. The aftermath is often marked by redness and blotchy patches, a bruised feeling, and intense pain that can be long lasting. I have ugly cried many times while having a shower, sobbing my way through them, and for a long time now I will only have one if no one is home, as it is also traumatizing for others in the house to hear me. I’m at a point where I can’t control my reactions to pain and I can’t shove that pain down inside anymore, and I really don’t want to subject my loved ones to that. 

Below the 3 types of Allodynia as follows:

1. Dynamic Allodynia (mechanical). Pain results from an object moving across your skin (wearing clothing, drying yourself off after a shower, shaving your legs, etc.).

2. Tactile Allodynia (static or cutaneous allodynia). Pain results from a gentle touch or pressure on your skin (like shaking someone’s hand, scratching yourself, or a gesture of comfort on the affected area).

3. Thermal Allodynia. Pain results from a change in temperature (like moving from indoors to outdoors, swimming, bathing, extreme weather conditions).

Allodynia is caused by central sensitization, a condition where the nervous system becomes overly sensitive to pain signals. This can lead to a vicious cycle, as the increased pain sensitivity can further exacerbate the condition.

Those who suffer from Allodynia, can also suffer from Hyperalgesia. Allodynia and Hyperalgesia are related issues that are very similar. Hyperalgesia is a symptom where you feel pain in situations where feeling it is normal, BUT the pain is much more severe and excessive than it should be. This happens because of disruptions in your body’s pain processes and is common with injury to nerves.

An example of Hyperalgesia would be feeling intense, excruciating pain when touching a recent burn or injury. It’s normal to feel pain after a burn or injury, but Hyperalgesia causes your nervous system to overreact in response to something painful, resulting in a blown out of proportion assault of pain signals peppering your brain.

With Hyperalgesia, it changes the way your body generates and processes pain signals. Those changes can happen because your pain receptors are firing more often than they would under normal circumstances, which makes the pain feel more intense.

You also respond faster to the stimuli than it would if you didn’t have it, as it causes you to react faster. This is because your body gives pain signals an unusually high priority and responds to them faster than expected.

Another common struggle is the pain signals don't stop firing even after the painful event is over. Your pain receptors remain overly sensitive, and that causes them to keep sending pain signals after they should have stopped.

There are two main ways that Hyperalgesia happens:

1. Primary Hyperalgesia. This is when an injury changes how you feel pain in the injured part of your body.

2. Secondary Hyperalgesia. This is when the way you feel pain changes in areas that aren’t directly affected by an injury or condition. This happens because of changes in how your nervous system handles pain signals.

Treatment for both Allodynia and Hyperalgesia typically involves managing the underlying causes and reducing pain. This may include medications, therapy, physical therapy, injections, or surgery. Early intervention is crucial to prevent the condition from worsening. Some of the treatments are invasive and can be traumatizing themselves, such as nerve blocks, nerve stimulation, and nerve ablations.

Both Allodynia and Hyperalgesia can have a significant impact on both physical and mental health. Sufferers, including myself, are not exaggerating or being overly dramatic. The pain we feel is much worse because of problems with how our body processes pain. It can limit daily activities, interfere with relationships, and lead to emotional distress. For those living with 1 or both of these conditions, it is essential to seek support and explore treatment options to improve quality of life.