Ross Hauser, MD

Formication is the sensation that insects are crawling on or under the skin when no insect is present. The word comes from formica, the Latin word for ant. Some people describe prickling, buzzing, stinging, moving clothing, water running over the skin, or an unexplained hot or cold feeling. These symptoms may fall under the broader medical term dysesthesia, meaning an abnormal and often unpleasant sensation.

At Caring Medical, we hear from patients who have these sensations along with chronic neck pain, headaches, arm tingling, imbalance, brain fog, or symptoms that changed after a whiplash injury or cervical surgery. Their experiences deserve a serious medical evaluation. They should not automatically be dismissed as anxiety, dementia, or a psychiatric disorder.

At the same time, it would be inaccurate to say that formication usually comes from the neck or that cervical instability has been proven to cause generalized crawling sensations. Formication has a wide differential diagnosis. In a subset of patients, irritation of a cervical nerve root or compression of the cervical spinal cord may be relevant—especially when the skin symptoms follow an anatomic pattern or occur with other neurologic signs.

This article explains what is established, what is based on case reports or observational findings, and what remains a proposed mechanism.

What we hear from people

Cervical fusion after whiplash and bugs crawling on my skin. One doctor thinks I have the onset of dementia.

I have had a cervical fusion. I “needed” this surgery because of a severe whiplash injury. I am still suffering from intense sharp neck pain. But it is a different sharp neck pain than the pain I had before cervical fusion. I guess the doctors fixed one pain and gave me another. I am now having issues with my bladder. I am also having memory and brain fog problems and my doctors actually think I am in the early stages of dementia. I told them that I do not think my problem is early-stage dementia, I think I have a neck problem. I asked them if my arguing the point coherently, wouldn’t that be proof enough my “neurological” problems are not “all in my head.” They still think it is a decline in my cognitive function caused by dementia. This is especially true when I complain that I have a sensation of things crawling on my skin. They throw mental illness in there as well and say I am depressed.

I am itching my head like crazy. I should probably not use the word crazy.

I suffer from many conditions, my doctors are focusing on chronic ear and sinus infections. I have “everything.” Hearing sensitivity, vision problems, choking sensation, dizziness, just some among many problems. I am also having problems which my doctors are suggesting may be some type of early-onset Alzheimer’s disease or dementia. I am way too young for this type of diagnosis yet my doctors are ordering a lot of brain scans. I do have confusion, brain fog, trouble focusing but I do not think it is dementia. I am having these weird symptoms that my doctors keep wanting to explore for my “brain,” problem. I have a sensation of “dissociative amnesia,” like I do not belong in the current reality and I forget who I am. I also have these sensations like something is crawling on my skin or there is something crawling in my scalp. I am itching my head like crazy. I should probably not use the word crazy.

My neck hurt. I had an adjustment. Then everything changed.

To be very, very clear, tactile hallucinations and formication are symptoms of neurological disorders and they are symptoms of possible psychiatric disorders. They are also symptoms and conditions of cervical spine and neck instability.

This is a story we hear very often and the main reason that someone winds up at our neck center. Everything has been tested for, little help or symptom alleviation was achieved, more medications, more tests, and no answers. Then one day someone facing all these problems mentioned to a health care provider, almost as an afterthought, that they had a very stiff and painful neck and if there was “something that could be done for that?”

In many cases, that person was sent off to physical therapy or most likely a chiropractor. Suddenly, everything changed for that person. Their story goes something like this:

I kept developing new symptoms, it seemed that every day something else popped up that I had not noticed before. More muscle cramping, tingling in my feet and arms, anxiety attacks, and racing heartbeat for some. I was even scheduled to have a cardiac evaluation. As with my other symptoms, my skin hallucinations were getting worse as well. One day I was in my living room and it felt like I was in the shower. One day my clothes felt like they were moving by themselves on my body.

I have always had nagging neck pain. Because of all these other symptoms, this problem was put on the back burner, and really never gave much thought other than taking a pill or rubbing my neck. As I look back I do remember sometimes when I would rub my neck and I would lose track of where I was or what I was doing. I thought that was just me responding to the small amount of relief the massage was giving me. Because my neck pain was flaring up and now I was developing more frequent headaches I went to a chiropractor. 

I had my adjustment, my neck felt better, and then I went home. As the day and next day passed I noticed that my symptoms and conditions were greatly reduced. I started having a panic attack because I did not know what this meant. I went online and started seeing that neck instability may be a cause of my problems and somehow this one adjustment was not only working on my neck pain but on my symptoms. Slowly the symptoms came back but I felt as if I had made a discovery, there was a connection between my neck pain and the feeling of ants crawling on my skin.

I went back for more adjustments and I found the symptoms I suffered from lessened but they also came back. I started searching for a more long-term solution and started to explore everything with cervical fusion surgery as the last resort if I could not find any other treatment.

What are formication, paresthesia, and tactile hallucinations?

These terms overlap, but they are not interchangeable:

• Paresthesia is an abnormal sensation such as tingling, pins and needles, or numbness. It may or may not be uncomfortable.
• Dysesthesia is an abnormal sensation that is usually unpleasant. It can include burning, itching, crawling, stinging, coldness, or pain without a primary skin disorder.
• Neuropathic itch is itching caused by dysfunction or injury somewhere along the sensory nervous system rather than by a primary rash or allergy.
• Formication specifically describes a crawling or insect-like sensation.
• Tactile hallucination means feeling touch or another bodily sensation without an external stimulus. The term describes the perception; it does not, by itself, identify the cause.
• Delusional infestation is different. It is a fixed belief that the body or environment is infested despite the absence of medical evidence. A person can experience formication without holding this belief.

Dermatology literature recognizes that dysesthesia can arise from nerve trauma, impingement, or irritation and may occur without a primary skin lesion. (1) A 2025 review likewise describes neuropathic itch as abnormal sensory signaling and discusses nerve compression in conditions such as brachioradial pruritus, a localized burning or itching sensation commonly affecting the outer forearm. (2)

This distinction matters. A crawling sensation is real to the person experiencing it even when the skin looks normal. The next task is to determine where the altered signal is coming from.

Formication has many possible causes

Formication is a symptom, not a diagnosis. Before attributing it to the cervical spine, a clinician should consider common and important alternatives.

 

Skin and infectious causes

True infestation, contact dermatitis, eczema, scabies, fungal disease, urticaria, dry skin, and other dermatologic disorders can produce itching or moving sensations. A skin examination is especially important when there is a new rash, scaling, open sores, drainage, household spread, or relevant travel or exposure.

Peripheral nerve and metabolic causes

Diabetes, small-fiber neuropathy, peripheral nerve entrapment, shingles, vitamin B12 or folate deficiency, thyroid disease, kidney or liver disease, iron deficiency, and electrolyte abnormalities can alter sensory signaling. Symptoms that begin in both feet and gradually rise may point toward a length-dependent peripheral neuropathy rather than a neck disorder.

Medication, substance, and withdrawal effects

Stimulants and some prescription medications can produce formication or perceptual changes. Alcohol or sedative withdrawal can be dangerous. A medication review should include prescriptions, supplements, recreational substances, recent dose changes, and anything recently stopped. Patients should not abruptly discontinue a prescribed medicine without medical guidance.

Neurologic and psychiatric conditions

Migraine aura, multiple sclerosis, Parkinson disease, stroke, seizure disorders, neurodegenerative disease, and disorders involving the spinal cord can produce abnormal sensations. Anxiety, severe sleep deprivation, mood disorders, psychosis, and delusional infestation also belong in the differential.

Current reviews emphasize that delusional infestation may be primary or secondary to medical, neurologic, infectious, metabolic, medication-related, or substance-related conditions. (3) A careful history, physical examination, and targeted testing are therefore appropriate before a psychiatric explanation is assigned. (4)

Mental-health assessment can be an important and respectful part of care. It should not be used to end the medical investigation prematurely. Likewise, finding cervical degeneration on an image should not end the investigation, because age-related neck changes are common and may be incidental.

When can the cervical spine be relevant?

The cervical spine houses the spinal cord and gives rise to nerve roots that supply sensation and movement to the shoulders, arms, and hands. Abnormal skin sensations may occur when a cervical nerve root is irritated (cervical radiculopathy) or when the spinal cord is compressed (cervical myelopathy).

A pinched or inflamed cervical nerve root can produce pain, numbness, tingling, burning, or itching in a recognizable distribution. Brachioradial pruritus is one example. It often affects the outer forearm, may worsen with sun exposure, and has been associated with cervical spine pathology. This is established evidence that some apparently “skin” symptoms can be neurologic, but it does not prove that every crawling sensation originates in the neck.

Patients with localized arm or scalp symptoms may also find our discussions of neuropathic itch and brachioradial pruritus and tactile allodynia and temperature changes helpful.

Degenerative cervical myelopathy: an important diagnosis not to miss

Degenerative cervical myelopathy occurs when age-related narrowing or other structural change compresses and impairs the spinal cord in the neck. A published case described a patient who repeatedly reported a wet, gel-like bodily sensation and was initially thought to be delusional. Examination revealed myelopathic signs, MRI showed severe cervical cord compression, and the sensory dysesthesia resolved after decompression surgery. (5)

That report is important because it demonstrates biological plausibility: cervical cord disease can, in an individual patient, produce unusual bodily sensations. It is still a single case report. It cannot establish how frequently formication comes from myelopathy or predict whether surgery will resolve another patient’s symptoms.

A 2025 scoping review found that neck pain, loss of hand coordination, and altered hand sensation should increase suspicion for degenerative cervical myelopathy. (6) Diagnosis is often delayed; a 2025 systematic review and meta-analysis found an average interval of about 14.5 months from symptom onset to surgery or preoperative assessment in the studies that measured it. (7)

Cervical instability and formication: our clinical perspective

At Caring Medical, the patients who prompt us to investigate the neck generally do not have an isolated crawling sensation. They may report a history of whiplash, connective-tissue laxity, persistent pain after fusion, symptoms provoked by head position, headaches, dizziness, arm paresthesia, or a feeling that the neck cannot support the head. We evaluate the overall pattern rather than assuming that one symptom proves instability.

One clinical scenario retained from the original article is the patient who developed different neck pain after cervical fusion and adjacent-segment stress, followed by arm or body sensory symptoms. Another is the patient whose symptoms began after a whiplash injury. These histories can justify a careful neurologic and structural assessment, but temporal association alone does not establish causation.

In our clinical experience, some patients report that abnormal sensations fluctuate with neck posture or temporarily change after the neck is supported or treated. Such observations can help generate diagnostic questions. They are not controlled evidence, and forceful cervical manipulation may be inappropriate—particularly when myelopathy, fracture, arterial disease, severe instability, inflammatory disease, or other contraindications have not been excluded.

A proposed mechanism, not a proven explanation

We propose that excessive cervical motion or altered alignment could contribute to symptoms in selected patients through intermittent irritation of nerve roots, abnormal mechanical stress, or—when true canal compromise exists—effects on the spinal cord. The posterior columns of the cord transmit vibration, position sense, and discriminative touch toward the brain. Distorted input anywhere along sensory pathways can be perceived as tingling, crawling, burning, or other dysesthesia.

This is a plausible neurologic framework, not proof that ligament laxity causes formication. The strongest direct clinical evidence concerns recognized conditions such as radiculopathy, neuropathic itch, and compressive myelopathy.

We have reported cervical structural and neurovascular findings in 227 young adults evaluated at an outpatient neck center for chronic brain-based symptoms. The retrospective, cross-sectional study documented frequent forward head posture, reduced cervical lordosis, C1–C2 instability, smaller internal jugular vein and vagus nerve measurements, and enlarged optic nerve sheath measurements within this selected cohort. (9) The study did not investigate formication as an outcome, lacked an asymptomatic control group, and cannot establish that the imaging findings caused the reported symptoms.

An earlier Caring Medical paper described ligamentous cervical instability, altered cervical structure, and impaired cranial fluid outflow as a hypothesis for complex neurologic symptoms. (10) It should be read as a hypothesis-and-theory article, not a controlled treatment trial. These publications support further investigation of cervical structure in appropriately selected patients; they do not establish a general cervical cause for tactile hallucinations.

Readers seeking broader context may review our pages on neurologic-like symptoms associated with cervical instability, craniocervical and cervical instability, and post-fusion neck pain and headaches.

How we evaluate a patient with neck pain and unusual skin sensations

The goal is not to “prove the neck” at the first visit. It is to determine whether the sensory complaint fits a dermatologic, peripheral nerve, spinal cord, brain, systemic, medication-related, or psychiatric pattern—and whether more than one process may be present.

History and examination

We ask where the sensation occurs, whether it is one-sided, whether there is a visible rash, what triggers it, and whether neck position changes it. We review injury and surgical history, medication and substance exposure, sleep, hormonal changes, infections, systemic illness, and associated neurologic symptoms.

The examination may include skin inspection, strength, reflexes, sensation, coordination, gait, balance, and signs of nerve-root or spinal-cord involvement. Depending on the findings, appropriate conventional evaluation may include primary care, dermatology, neurology, psychiatry, toxicology, or spine surgery.

Testing is selected, not automatic

Blood testing may be appropriate for glucose control, blood count, liver and kidney function, thyroid function, vitamin B12 or folate, iron status, or other concerns suggested by the history. MRI is generally the key imaging test when spinal-cord compression, tumor, infection, or significant nerve-root disease is suspected. Electrodiagnostic testing or small-fiber neuropathy evaluation may also be considered.

At Caring Medical, dynamic imaging may be considered when symptoms and examination suggest abnormal motion not adequately explained by static studies. Our discussion of Digital Motion X-ray explains how motion can be assessed. Dynamic imaging findings must still be correlated with the patient’s symptoms and examination; motion on an image is not, by itself, proof of the symptom source.

Treatment depends on the diagnosis

There is no single treatment for formication. Treating an underlying vitamin deficiency, diabetes, thyroid disorder, infection, medication effect, neuropathy, psychiatric illness, or compressive spinal disorder requires different care. Neuropathic symptoms may sometimes be managed with topical treatments, medications, physical therapy, or condition-specific procedures. Patients with confirmed myelopathy require guideline-based spine care.

What are we seeing in this image? A possible answer? The messages to and from the brain are being delayed. Misinformation now fills the void as messages move more slowly

In other articles on this website, I explore problems that many of the people we see have. Symptoms include tactile allodynia or painful to the touch skin, skin sensations where one half of their body will feel hot and one half of their body will feel cold, rashes, and problems of sweating. The sensation is felt as the nerve impulses go up the posterior columns of the spinal cord to the parts of the brain that sense stuff that is the somatosensory centers of the brain. But what happens if this messenger-information highway has a roadblock or traffic is being diverted from and many of the highway lanes are closed? The messages move more slowly, priority messages may be delayed.

In this image, we see that this patient has cervical spine instability. This is allowing the rear or posterior spinal canal to hit against the walls of the spinal canal. The pressure being created by hypermobile, unstable cervical vertebrae was causing this patient’s whole body to be in a state of distress. They had the sensation that their body was buzzing or vibrating, their skin had different temperatures from one side to the other, and itching sensations consistent with the sensation that something was crawling on them. Our treatments to alleviate this patient’s problems focused on removing the pressure on the spinal cord by stabilizing the cervical vertebrae and restoring the natural curve of the cervical and thoracic spine with Prolotherapy injections. This is explained below.

 

Where Prolotherapy may—and may not—fit

Prolotherapy involves injection of an irritant solution, commonly dextrose, with the goal of stimulating a local healing response in injured connective tissue. At Caring Medical, we may consider it for carefully selected patients when the history, examination, and imaging support painful ligament injury or cervical instability and urgent surgical disease has been excluded.

A 2014 narrative review by Steilen, Hauser, Woldin, and Sawyer proposed capsular ligament laxity as a contributor to chronic neck pain and discussed Prolotherapy as a treatment option. (11) In a 2015 retrospective study of 21 patients treated for cervical instability and chronic neck pain, patients reported improvements in pain and function after Prolotherapy. (12)

These studies are foundational to our clinical approach, but their limitations are substantial. The 2014 article is a narrative review, and the 2015 study was small, retrospective, uncontrolled, and based largely on patient-reported outcomes. Neither was a randomized controlled trial of formication. Therefore:

• Prolotherapy has not been proven in controlled trials to treat formication or tactile hallucinations.
• Improvement in an individual patient cannot establish that cervical instability was the sole cause.
• Injection treatment is not appropriate for every patient and carries risks that require informed consent and an experienced clinician.
• Suspected spinal-cord compression, progressive neurologic loss, infection, fracture, tumor, or vascular emergency must be evaluated through conventional pathways first.

Our treatment goal is not simply to chase a crawling sensation. It is to identify a coherent, treatable musculoskeletal problem when one is present and to coordinate other care when it is not.

Summary: unusual skin sensations deserve a complete evaluation

Formication can be distressing, but it should not automatically be labeled dementia, psychosis, or “all in your head.” It can arise from skin disease, systemic illness, medication or substance effects, peripheral neuropathy, brain disease, psychiatric illness, cervical nerve-root irritation, or cervical spinal-cord compression.

Established evidence shows that nerve and spinal-cord disorders can create dysesthesia and neuropathic itch. A case report shows that severe cervical myelopathy can occasionally present with an unusual whole-body sensory experience. Caring Medical’s broader proposal—that ligamentous cervical instability contributes to formication in a subset of patients—remains a clinical hypothesis requiring better controlled research.

For a patient who has crawling sensations plus neck pain, arm symptoms, hand clumsiness, imbalance, or symptoms following cervical trauma or surgery, it is reasonable to ask whether the cervical spine should be evaluated. It is equally important to keep the differential diagnosis broad and to act quickly when neurologic red flags are present.

References

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