The key difference between allodynia and hyperalgesia is that allodynia is the pain due to a stimulus that does not usually provoke pain, while hyperalgesia is the increased pain from a stimulus that usually provokes pain.
Neuropathic pain is described as shooting pain or burning pain. Normally, this pain can go away on its own or be a chronic condition. Neuropathic pain happens when your nervous system is damaged or not working correctly. This pain can be felt from any of the various levels of the nervous system. Allodynia and hyperalgesia are two symptoms of neuropathic pain.
CONTENTS
1. Overview and Key Difference
2. What is Allodynia
3. What is Hyperalgesia
4. Similarities – Allodynia and Hyperalgesia
5. Allodynia vs Hyperalgesia in Tabular Form
6. Summary – Allodynia vs Hyperalgesia
What is Allodynia?
Allodynia is a symptom of the neuropatic pain. Someone who suffers from it feels unexpected pain from non-painful stimuli like a light touch, washing the face, brushing their own hair, or a breath of air. The characteristics of allodynia are mild to severe pain, a burning sensation, an ache, or squeezing pain. Allodynia can be divided into three types; thermal allodynia (pain occurs when there is a mild change of temperature on the skin), dynamic or mechanical allodynia: movements like bedsheets pulled across the skin cause pain) and static or tactile allodynia (a light touch or pressure on the skin causes touch). Allodynia is triggered by damaged nerves, which become hypersensitive or may happen when nerves carry pain messages incorrectly. The risk factors for allodynia include migraine, postherpetic neuralgia, fibromyalgia, diabetic neuropathy, and complex regional pain syndrome.
Allodynia is diagnosed through medical history, physical examination, and questionnaires. Furthermore, treatment options for allodynia include lifestyle choices (light exercises, following a varied diet, getting enough sleep, quitting smoking), medications (pregabalin tablet, anticonvulsant tablets, anti-depressants, topical pain medications, topical creams containing menthol or capsaicin, other topical applications like gabapentin, ketamine, salicylates, and other ingredients), psychotherapy, physical therapy, nerve blocks, nerve stimulators, and surgery.
What is Hyperalgesia?
Hyperalgesia is a symptom where people feel excessive or severe pain in a situation where the pain is normal. There are two main types of hyperalgesia: primary hyperalgesia and secondary hyperalgesia. Primary hyperalgesia is when an injury changes how people feel pain in the injured part of their body. On the other hand, secondary hyperalgesia is when the way people feel pain changes in areas that aren’t directly affected by an injury. Hyperalgesia is triggered by burns, bites or stings, cancer, complications from medication like opioids, diabetes-related neuropathy, immune and inflammatory conditions like lupus, multiple sclerosis, migraines, pain disorders like complex regional pain syndrome, central pain syndrome, and trauma. Moreover, the risk factors for hyperalgesia include poor sleep quality, high-dose opioids, and parenteral opioid administration.
Moreover, hyperalgesia is diagnosed through a medical history, a review of a person’s medication, and a physical examination. Furthermore, hyperalgesia is treated through medications (acetaminophen, anti-depressants, anti-seizure medications, local anesthetics, NSAIDs, and steroids medications), nerve ablation, nerve blocks, and transcutaneous electrical nerve stimulation (TENS).
What are the Similarities Between Allodynia and Hyperalgesia?
- Allodynia and hyperalgesia are two symptoms of neuropathic pain.
- Both are characterized by feeling pain.
- They can be triggered by underline health conditions.
- Both can be diagnosed through medical history and evaluation of physical symptoms.
- They are mainly treated through specific medications.
What is the Difference Between Allodynia and Hyperalgesia?
Allodynia is the pain due to a stimulus that does not usually provoke pain, while hyperalgesia is the increased pain from a stimulus that usually provokes pain. Thus, this is the key difference between allodynia and hyperalgesia. Furthermore, allodynia is trigged by damaged nerves which become hypersensitive or may happen when nerves carry pain messages incorrectly. On the other hand, hyperalgesia is triggered by burns, bites or stings, cancer, complications from medication like opioids, diabetes-related neuropathy, immune and inflammatory conditions like lupus, multiple sclerosis, migraines, pain disorders like complex regional pain syndrome, central pain syndrome, and trauma.
The below infographic presents the differences between allodynia and hyperalgesia in tabular form for side-by-side comparison.
Summary – Allodynia vs Hyperalgesia
Neuropathic pain is caused by damages or diseases that usually affect the somatosensory system. It is characterized by symptoms such as allodynia and hyperalgesia. Allodynia is pain due to a stimulus that does not usually provoke pain. Hyperalgesia is the increased pain from a stimulus that usually provokes pain. So, this is the summary of the difference between allodynia and hyperalgesia.
Reference:
1. “Allodynia: Causes, Types, and Treatment.” Medical News Today, MediLexicon International.
2. “Hyperalgesia: What It Is, Causes, Symptoms & Treatment.” Cleveland Clinic.
Image Courtesy:
1. “Hyperalgesia and allodynia” By Richard Lennertz – Own work (CC BY 4.0) via Commons Wikimedia