Small fibre neuropathy is caused by damage to the peripheral nervous system’s small fibers. These little fibers sense sensations of pain, heat and scratching in the skin. These also control cardiovascular system and gastrointestinal tract autonomic functions.
Damage to the peripheral nervous system affecting the small fibers can cause burning pain or tingling sensations starting at the feet and moving up the legs to the rest of the body.
Often small fiber neuropathy can be a symptom of underlying health problem, such as diabetes or an autoimmune disease.
Continue reading to learn more about the causes and signs of fiber-small neuropathy and how doctors diagnose and treat this disorder.
Symptoms
The most common early symptom of minor fiber neuropathy is pain in the feet and hands. This disease may also reduce the ability of the body to feel pain in a concentrated area and sense temperature, however.
People may experience signs in their knees, legs and arms as the disease progresses.
Other symptoms of neuropathy with small fibres include:
- a tingling or prickling sensation (paresthesia)
- hypersensitivity to touch and temperature changes
- numbness in the feet, legs, or lower stomach
- bladder control issues
- constipation
- sexual dysfunction
- excessive or infrequent sweating
- skin discoloration
- dry eyes and mouth
- extremely low blood pressure that may cause fainting
- rapid or irregular heartbeat
Symptoms of small fiber neuropathy can range from mild to severe. In the early stages, people often experience mild symptoms that may go unnoticed. Over time, symptoms typically worsen and progress to other areas of the body.
Causes
As a result of an underlying medical condition, people frequently experience small fiber neuropathy, such as diabetes. Up to 50 per cent of people with prediabetes or diabetes can experience small fiber neuropathy, according to the National Institutes of Health (NIH).
The NIH also notes the mutations in the genes SCN9A and SCN10A may cause minor neuropathy to the tissue. These genes carry instructions for sodium channels, which are used by cells to generate and transmit electrical signals.
Examples of medical conditions that may cause neuropathy with small fibre include:
- metabolic and endocrine disorders
- celiac disease
- Sjogren’s syndrome
- primary systemic amyloidosis
- familial amyloidosis
- Fabry disease
- sarcoidosis
- lupus
- fibromyalgia
- HIV
Other causes include:
- vitamin B-12 deficiency
- alcohol use disorder
- exposure to chemotherapy
- physical injuries
- illicit or prescription drug use
If they do not determine an underlying cause, a doctor can diagnose a individual with idiopathic small-fiber neuropathy. Researchers found in a 2018 study of 921 people with small fiber neuropathy that 53 per cent of study participants had no underlying condition associated with it.
Diagnosis
When diagnosing small fibre neuropathy, doctors use a wide range of medical tests. We will start the diagnostic process by reviewing the medical history of a patient and doing a physical examination.
A doctor may ask questions about the medical history of a person’s family, as well as any current or previous medical conditions which may explain their symptoms.
For the diagnosis of small fiber neuropathy, many medical professionals consider skin biopsies as the “gold standard” method. A biopsy of the skin is a minimally invasive procedure in which a doctor takes several small samples of the skin they submit for examination to a laboratory.
The skin samples are studied under a microscope by a technician or pathologist. If the skin samples have less small nerve fibers than healthy skin, a doctor can diagnose small fibre neuropathy.
A doctor may also, in some cases, perform a nerve conduction examination, electromyography, or both. Although with these tests doctors can not conclusively diagnose small fiber neuropathy, they can use them to rule out other peripheral neuropathies and muscle disorders.
If necessary, physicians can use laboratory tests to check for signs of glucose intolerance, immune system dysfunction, vitamin deficiencies and liver or kidney abnormalities in a person’s blood or urine.
Treatment
Treatment for neuropathy with small fibers varies depending on the underlying cause. Individuals can find that when they approach or receive treatment for the underlying medical condition their neuropathy symptoms improve or disappear entirely.
That involves regulating blood glucose levels, maintaining a normal body weight, and eating a healthy, balanced diet for people who have diabetes or other metabolic disorders.
Exercising regularly and quitting smoking may help to heal the constricted blood vessels that provide the nerves with vital nutrients.
Doctors can prescribe immunosuppressive drugs to treat people who have autoimmune diseases. These drugs inhibit immune response and decrease inflammation in the body.
Due to small fibre neuropathy, other treatment options may help reduce discomfort. These can include:
- antidepressants
- antiseizure medication
- lidocaine creams and patches
- narcotics or opioid-based pain medications
Summary
Small fibre neuropathy is a form of peripheral neuropathy which affects the skin’s small nerve fibers.
This condition typically causes a feeling of uncomfortable tingling or burning pain in the feet. Nonetheless, people with minor fiber neuropathy may have decreased heat sensitivity and some forms of pain.
While small-fibre neuropathy symptoms usually begin in the feet, they can also affect the legs, hands, arms, and torso.
As a result of nerve damage from another underlying medical condition, such as diabetes, an autoimmune disease, or injury, people can develop small fiber neuropathy.
Therapies are affected by the underlying cause. Managing the underlying medical condition can in most cases alleviate the symptoms of neuropathy with small fibres.
