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I got experimental data where hypersensitivity (i.e. tonic pain when touching ear canal) was recognised for about 100 minutes.

I do not know which type of hypersensitivity is this one. IgM can reach ear canal, I think (not sure) - it is just in the limit. If IgM cannot reach ear canal, then the hypersensitivity must be caused by

  • humoral immune system

which is responding slowly to the trigger.

It is proposed that this cannot be contact dermatitis because

  • the reaction happened simultaneously in both ear canals

after irritating ear canals with plastic the subject is not allergic. Irritation was also a selected signal which resulted in the dynamic cycle of bass music by Beats earphones. It was studied the effect of the specific signal with bass music on the movement on the inner membrane on the subject with problem in maintaining the inner physiology of ear itself (also repeated cycle of ear infections during childhood).

Can IgM reach ear canal?

The hypersensitivity was simultaneous in both ear canals. I did not know before that you can get hypersensitivity reaction in ear canals and also simultaneously. I think hypersensitivity is not in normal condition. There must be some etiological factors (probably neuronal) that can cause it.

There are other organs which can have hypersensitivity too. So I started to think what is the trigger of hypersensitivity.

My conjecture is about Secreted substances of endothelium (EDRF, EDCF). There are three types of substances secreted by the endothelium

  • NO
  • Endothelium hyperpolarising factors
  • Endothelins

NO is the most important one. But what is its role in the hypersensitivity of ear canal is unknown to me.

What is the mechanism of hypersensitivity of our body and particularly in the ear canal?

Léo Léopold Hertz 준영
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This answer is based on embryological studies and is limited. I will extend it later when understand better.

Sensory areas

  • maculae acusticae - walls of utricle and saccule (this most probable area)
  • cristae acusticae - change in body position

Nerve

  • vestibular fibers of cranial nerve VIII (TODO each branchial arch has a nerve - how these differentiate between different arches?)

Embryonal Ganglion

  • statoacoustic (spinal) ganglion (19.5 C Fig)

Embryonal ganglion splits into two

  • cochlear portion
  • vestibular portion

which supply sensory cells of organ of Corti, and those of the saccule, utricle and semicircular canals, respectively

Branchial Arches

Each arch has a vessel, cartilage and nerve. The task is to understand which part of embryonal ear is able to start hypersensitivity reaction.

Middle ear

Tympanic Cavity and Auditory Tube

  • origin endoderm (1st pharyngeal pouch) - malleus and incus
  • malleus - 2nd a.a.a.

Eardrum or Tympanic Membrane

  • ectodermal epithelial lining at bottom of auditory meatus
  • endodermal epithelial lining of the tympanic cavity
  • intermediate layer of connective tissue (See Langmans' Fig 19.9B). TODO this part is superficially covered in Langmans.

Auricle

  • 6 mesenchymal proliferations at dorsal ends of 1-2 a.a.a.

TODO I must look again embryonal slides of ear to see where the nerves occur first and how they develop.

Sources

  1. Langmans Medical Embryology, 12th ed, 2011
  2. My notes of Embryology classes, Spring 2014 (I did not have all my notes now so must study these things again after holiday)
Léo Léopold Hertz 준영
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