Paresthesias are a common symptom of fibromyalgia and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Paresthesia is defined as abnormal sensations such as tingling, crawling, itching, numbness, and prickling.
Most of the time, paresthesias aren't painful. However, due to abnormal pain processing and nervous system activity, people with fibromyalgia and ME/CFS often report that they do cause pain.
This article looks at what paresthesias are like in fibromyalgia and ME/CFS, what causes them, and how they're treated.
Paresthesias in Fibromyalgia and ME/CFS
In fibromyalgia and ME/CFS, paresthesias can be of any severity and get more or less bothersome over time.
Virtually no research has been done on paresthesias in ME/CFS. However, enough people with the condition report paresthesias that they're generally accepted as a symptom.
In fibromyalgia, paresthesias have received some attention from researchers and are well established as a symptom of this disorder.
Paresthesias in fibromyalgia and ME/CFS often come and go rather than being a constant sensation. They can strike without warning and usually without an obvious trigger. In some cases, fatigue, stress, illness, or sensory overload may trigger an array of symptoms, including paresthesias.
These sensations can be anywhere in your body, but they're most common in:
- Feet
- Hands
- Face
According to one study, painful paresthesias may be more common in people with fibromyalgia who have certain personality and mental health traits. These include:
- Illness-related psychological distress
- High harm avoidance (e.g., staying in bed due to fear of exacerbating their illness)
- Low self-directedness
The specific relationship between these traits and paresthesias isn't clear. It may be that:
- The pain of paresthesias contributes to these behaviors
- Paresthesias are worsened by the consequences of these behaviors (e.g., someone with low self-directedness not sticking to their treatment regimen)
- This array of symptoms shares an underlying cause
It'll take more research to say for sure what's the cause and what's the effect.
Smoking and Paresthesias
Multiple studies show that smoking makes fibromyalgia symptoms worse. An early study suggests that cigarettes are related to more severe pain specifically from paresthesias. Quitting smoking may help alleviate the pain and lessen your overall symptom load.
Causes
In the general population, paresthesias are commonly caused by:
- Damage to peripheral nerves (those in the arms and legs)
- Pressure on those nerves, possibly from inflammation or injury
- Chemotherapy drugs
Most of the time, though, the cause is unknown.
Nerve damage or pressure may be responsible for paresthesias in fibromyalgia and ME/CFS, as well. It may also be caused by a combination of other factors. Researchers have uncovered several possibilities.
Central Sensitization
In fibromyalgia and ME/CFS, one hypothesis is that paresthesias (and other abnormal pain types) are the result of central sensitization. That term is used to describe a hyper-sensitive central nervous system (brain and spinal cord).
Central sensitization causes nerve sensitivity and an amplified pain response in the brain. That could mean that nerve stimulation that people wouldn't find painful is painful to people with fibromyalgia or ME/CFS.
Inflammation
The role of inflammation in these conditions has been one of long debate. Now, however, it does appear that ME/CFS is associated with inflammation in the brain and spinal cord. At least some cases of fibromyalgia may be as well.
According to one older study, fibromyalgia may also involve inflammation in the body-wide web of connective tissues called the fascia. That inflammation may put pressure on nerves and cause or contribute to paresthesias.
Autoimmunity
Autoimmunity has been another contentious area of fibromyalgia and ME/CFS research. Now, a growing body of research points to autoimmunity, at least in subgroups of people with these conditions and possibly in all of them.
In autoimmune disease, the immune system mistakes a healthy, normal part of your body for a threat, such as a virus or bacterium. It then makes antibodies (specialized cells) to seek out and destroy that part.
In fibromyalgia and ME/CFS, damage from autoimmunity could explain paresthesias (as well as many other symptoms). It may be that the immune system is attacking and damaging the nerves themselves or other components of the nervous system that make the nerves dysfunctional.
Small Fiber Neuropathy
A related line of inquiry involves problems with small nerve fibers in your skin, organs, and the nerves of your arms and legs. These are called sensory nerves.
Sensory nerves provide sensation for your skin (your sense of touch) and control the function of your autonomic nervous system (which controls automatic functions like breathing, heart rate, and body temperature).
Research has tied both fibromyalgia and ME/CFS to dysfunction of these sensory nerves, which is called small fiber neuropathy.
Small fiber neuropathy is known to cause paresthesias. This may be due to inflammation compressing the nerves, damage from an autoimmune process, or both.
Spinal Cysts
A type of spinal-cord cyst called a perineural cyst may cause some cases of painful paresthesia in fibromyalgia and ME/CFS.
Perineural cysts are sacs of cerebrospinal fluid that grow on nerve roots (where nerves branch off from the spinal cord). The pressure they put on nerve roots can cause paresthesias and other types of nerve pain, including sciatica.
A 2021 study looked at how common these cysts are in people with fibromyalgia and/or ME/CFS compared to people without either condition. In the fibromyalgia/ME/CFS group, they were three times more common than in the control group.
Perineural cysts are known to cause pain at the site as well as in other areas of the body that may seem unrelated to their location but are actually along the path of the same nerve.
Researchers concluded that perineural cysts (also called Tarlov cysts) may be linked to these conditions, possibly through central sensitization or other nerve and spinal cord abnormalities. They also stated that the cysts could contribute to small fiber neuropathy.
Carpal Tunnel Syndrome?
Paresthesias in the hands and feet, especially nerve "zings," may be due to carpal tunnel syndrome or the similar condition tarsal tunnel syndrome. Both are common in fibromyalgia. Without treatment, they can lead to permanent nerve damage. Be sure to report these symptoms to your healthcare provider.
Treatment
When paresthesias aren't painful or disruptive, they don't need to be treated. But when they are painful, your healthcare provider may recommend several treatments.
Some medications for peripheral neuropathy are used to treat fibromyalgia, including:
These medications may "quiet" your nerves and relieve paresthesias and other symptoms.
Depending on the cause of your paresthesia, other medications may help, as well. These are:
- Non-steroidal anti-inflammatory drugs (NSAIDs) to lower inflammation
- Immunosuppressants to suppress autoimmunity
- Drainage, steroid injections, and surgical removal for perineural cysts
Neurologists and rheumatologists are the healthcare providers with the best understanding of paresthesias and how to treat them.
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Summary
Paresthesias are odd nerve sensations. Painful paresthesias are a symptom of both fibromyalgia and ME/CFS and most common in the feet, hands, and face. In other people, they're generally not painful.
Paresthesias may have any combination of several possible causes, including central sensitization, inflammation, autoimmunity, small fiber neuropathy, or perineural cysts.
Treatment may involve neurpathy medications, anti-inflammatories, immunosuppressants, and drainage or removal of cysts.