Skin Biopsy Results for small nerve fiber

[massie7899]

I have history of neuropathy initially in my feet and thighs, now in my biceps. My QSART was low/absent but skin biopsy was normal but commented as "unusual and extremely high value . My thigh results was 28.34. and calf was 17.4. .It stated that it maybe unusual form of small fiber neuropathy. What else can cause extremely high values.  thanks

[massie7899]

Thank you very much for your excellent advise. I will follow through with your recommendations

[Dr. Kokil Mathur]

Hi!

A reduced or absent QSART is indicative of small fiber neuropathy. Skin biopsy is done to measure the density of small sensory fiber nerve endings and the density of autonomic nerve fibers in the sweat glands. The two standardized tests for this are the Epidermal Nerve Fiber Density (ENFD) (for small sensory nerve fibers density) and the Sweat Gland Nerve Fiber Density (SGNFD) test (small autonomic nerve fibers density). Usually both ENFD and SGNFD are reduced or the ENFD test may be normal but SGNFD is reduced.
Other conditions which mimic small nerve fiber neuropathy are multiple sclerosis or myelopathy, Regional Pain Syndrome (RSD), Reflex Sympathetic Dystrophy, polymyalgia rheumatica, Erythromelalgia, fibromyalgia, Raynaud syndrome, restless leg syndrome, fasciitis, neuroma, or anxiety or depression induced somatic pains. In these cases the ENFD and SGNFD may be normal or rarely raised. Hence, in your case since the skin biopsy results are not reduced, and even though QSART is reduced/absent, other causes mentioned above should be looked into. Hope this helps. Take care!

The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.