From the Guidelines
Small fiber neuropathy can be caused by exposure to various toxins, including certain chemotherapy drugs, heavy metals, industrial chemicals, and pesticides, as well as excessive alcohol consumption and certain medications. The most recent and highest quality study, 1, highlights that small fiber neuropathy represents affection of nerve terminals of fibers involved in temperature and pain perception, which is present in patients treated with vinca alkaloids, taxanes, thalidomide, and bortezomib. Some key points to consider include:
- Certain chemotherapy drugs, such as platinum compounds, taxanes, and vinca alkaloids, can cause small fiber neuropathy, as noted in 1.
- Heavy metals like lead, mercury, arsenic, and thallium can damage nerve fibers by interfering with cellular metabolism and causing oxidative stress.
- Industrial chemicals, including n-hexane, acrylamide, and organic solvents, are significant causes of small fiber neuropathy, particularly among workers in manufacturing, painting, and cleaning industries.
- Pesticides and herbicides containing organophosphates can cause neuropathy through cholinesterase inhibition.
- Excessive alcohol consumption is another common toxin that damages small nerve fibers through direct toxic effects and nutritional deficiencies.
- A thorough occupational and medication history is essential to identify potential toxic exposures, as removing the offending agent is often the first step in treatment and can sometimes allow for partial nerve regeneration and symptom improvement, as discussed in 1.
From the Research
Possible Exposures to Toxins
Possible exposures to toxins that can cause small fiber neuropathy include:
- Chemical substances, as seen in patients with multiple chemical sensitivity syndrome 2
- Other environmental toxins, although specific examples are not provided in the available evidence
Associated Conditions
Small fiber neuropathy can be associated with various conditions, including:
- Metabolic diseases, such as diabetes mellitus and glucose intolerance 3
- Dysimmunity syndromes, such as Sjögren's syndrome and sarcoidosis 3
- Genetic abnormalities, such as familial amyloidosis and Fabry disease 3, 4
- Inflammatory diseases, although specific examples are not provided in the available evidence 5
Diagnosis and Treatment
Diagnosis of small fiber neuropathy can be made through various tests, including:
- Skin biopsy to assess intra-epidermal nerve fiber density 3, 2, 4
- Autonomic tests and laser-evoked potentials 5, 3 Treatment options for small fiber neuropathy include:
- Symptomatic treatment, such as pain killers and antidepressants 4
- Pathophysiologic treatment, such as immunosuppression or immune-modulation 4
- Causal treatment, such as addressing the underlying metabolic or genetic disorder 4
- Intravenous immunoglobulin therapy, although its efficacy is still being investigated 5, 6