skin biopsy for SFN negative

[Nymph]

After two trials of my skin biopsy, no SFN was found! This does not rule out SFN, because it can be patchy, but it makes me think that my autonomic symptoms are possibly based on genetic factors (hypermobility/ mast cell activation), instead. At this point I am not going to seek further diagnoses unless things get worse. It's reassuring that I might not need to consider harder-hitting drugs (Rituxan, Imuran) anytime soon. Instead I am going to keep up my sodium/H2O loading, compression wear, and add quercetin as a mast cell stabilizer. I am doing quite well otherwise. My mild paresthesias and dropping things.... well.... we'll see what the neuro says next week. I guess I just feel like moving on. 

[anita]

I have a question or two.  Did you see the report?  Are they only saying that the nerve density is within normal limits?  Did they check the morphology (condition of the fibers)?  I ask because it is possible to have normal density yet the fiber condition be quite abnormal...which can still be a sign of SFN.  Actually, some pathologist (therapath, for one) does not even check the condition of the fibers.    Just a thought.

[Nymph]

Thanks, Anita. I have not seen the report yet but this is a good reminder to ask for it! I will let you know. Also, I have heard of people having a positive Q-sart despite a negative biopsy. We shall see. I will look for the fiber condition and let you know.

[Nymph]

Got it today. It says: "Neither an abundance of axonal swellings nor fiber atrophy is seen. There is no histopathologic evidence of active vasculiits or amyloid depletion." Sensitivity of the test: 70-90%

[anita]

It seems they checked for condition of the fibers and it wasn't remarkable for signs of SFN.  Just curious, how many sites did they check...and what were the locations?

[Nymph]

Two - outside of my left thigh and outside of my left calf.

POTS can have a number of other causes and I have had some weird symptoms for a long time.

For the other symptoms I have no explanation.

[anita]

Exactly right...POTS can have a number of causes.

It's sort of a shame the report wasn't more detailed...with percentile of density and actual fiber condition (instead of general overview).  I say this because if your condition progresses the biopsy can be repeated down the road and compared to this baseline one...for signs of changes.  That is the one great benefit of this biopsy...being able to be repeated.

[Nymph]

Yes, it gave the density, sorry! 22/mm at thigh; 10/mm at calf. Totally average, apparently, although the calf count is less than 60% of the thigh count, which is supposed to be the ratio. So that's something to ask at my neuro consult, anyway. And, yes, it can always be repeated and compared. I'm glad I have the info.