Let's keep things simple and practicle. If there is a known parasite located in the area it is highly probable, without a doubt, that the parasite is causing pain/inflammation in the area, and not some so-called "sleep hormone toxin".
I may agree with you on some very small points, but some of them are getting mixed up in your hypothesis. As far as I know, I've never heard of "sleep hormone toxin" which is why I would like to see some write-up on this. I've been around a long time, read a lot, and have never heard of this as the CHIEF cause of stinging in the throat.
Thank you in advance for supplying the info because I'm always interested in learning new information. :)