I finally took a picture of my hand after washing in warm water. The turning-red thing has been going on for a couple of years and it was much worse when it first started - but I could never remember to take a picture back then. I get a bit more brain-foggy than usual when it happens. I think it's erythromelalgia. It used to burn and hurt, but not much, if at all, these days. My feet used to do it, too - either triggered by taking a hot shower or when working in the heat outdoors. That doesn't happen anymore. Maybe the low dose naltrexone helped, or maybe it was just time.

I got the LDN Rx online after reading this case report. The patient had worse symptoms than me (1). I asked for the LDN based on other chronic pain and eczema, since I had diagnoses for those and they are recognized indications for LDN.

I noticed her 2nd and 3rd toes are a bit fused, like mine. Not quite syndactyly. There's another case report on a baby boy with an SCN9A/Nav1.7 mutation who had 2nd and 3rd toe syndactyly along with pain insensitivity. His mother also had the mutation and
2nd and 3rd toe syndactyly, but she had pain hypersensitivity. I have wondered about the difference in phenotype being due to sex differences.

Under 'Treatment' in the 2nd case report, naloxone is discussed as a possibility, but no information is given as to whether the patient was given naloxone or his response.

1 - https://doi.org/10.25251/skin.4.3.15

2 - CW: there are disturbing pictures in this article of injuries to the baby boy's hands caused by him chewing on them.
https://pubmed.ncbi.nlm.nih.gov/30834170/

#erythromelalgia #pain #LowDoseNaltrexone #SCN9A #nociception #SodiumChannels

Animalogic put out an interesting Floralogic episode on the extreme, long-lasting pain caused by gympie gympie - a plant in the same family as stinging nettle -

Gympie Gympie Is Doing Everything It Can To Ruin Your Life
https://youtu.be/kIGQYE8pH_Y?si=4QN-DzBHdRg3OEen

It's an Australian plant, of course.

"Altering the activation threshold, combined with effects upon inactivation, likely leads to nociceptor activation and the sensation of pain, akin to biophysical changes observed in painful conditions associated with NaV1.7 [SCN9A] gain-of-function mutations such as inherited erythromelalgia (IEM) and paroxysmal extreme pain disorder (PEPD), respectively ... As the gympietides bear little similarity to any other known NaV modulators and display unusual effects particularly on NaV inactivation, it is difficult to predict possible binding sites at this point. However, based on activity of animal venom–derived toxins and the biophysics of NaV gating, the extracellular loops of the domain IV voltage sensor could be a possible binding site."
https://doi.org/10.1126/sciadv.abb8828

#Pain #nociception #NaturalProducts #erythromelalgia #gympietides #SodiumChannels #SCN9A

#Neanderthal #gene variants associated with greater #pain_sensitivity.

#evolution #anthropology #SCN9A #introgression #anthropogenomics

https://phys.org/news/2023-10-neanderthal-gene-variants-greater-pain.html