I believe that my post-COVID scenario closely resembles yours, and like you, ENTs and other specialists have been unable to pigeon-hole or assign a cause to the congestion that migrates across my sinuses, nasal passages, eustachian tube, and inner ears. I feel blessed that I don´t have post-exertional malaise/weakness, but like you, the difficulty I experience with blocked nasal breathing, tinnitus, ear/eustachian tube pain, and headaches is crazy-making and unlike anything I ever experienced prior to my mild and short case of COVID seven months ago.

I have posted across multiple topics here, and if you have spotted my posts, youĺl note that after massive amounts of self-directed research through both peer-reviewed publications and popular writings, I have settled on an approach in which I now have a great deal of confidence. Ultimately, I discovered the work of Dr. Derrick Lonsdale, a genuinely brilliant and rigorous scientist and clinician who devoted the latter portion of his career to establishing that syndromes like what you and I are experiencing now, especially when following on a tremendous stressor (like a viral infection) are potentially traceable to neurological dysregulation that, in the view of an increasing number of researchers, generates many of the features, in subacute form, of the well-known nutritional deficiency disease beri beri.

I have a large notebook of materials on all this that I am still wading through, and I am committed to reading Dr. Lonsdaleś main opus on the prevalence of thiamine deficiency and associated dysautonomia in the general population.

In the interim, relying on a variety of protocols developed by followers of Dr. Lonsdaleś research, I started on thiamine supplementation about 8 weeks ago, very slowly and gradually increasing the strength of my daily dose, and moving from more commercial sources of thiamine to the form that Dr. Lonsdale popularized through his clinical practice (TTFD). A few weeks in, I was clearly still stalled, and so I worked with my primary care doctor to taper and replace maintenance medications that, it turns out, were probably constantly depleting my thiamine levels, and now I am finally starting to see some changes in my respiratory picture. This will be a long haul, but I intend to tough this out, because I have identified no long-COVID clinics in the U.S. that appear to be offering treatments based on any deep understanding of the COVID virus´s harmful action on multiple metabolic pathways.

Importantly, I have come to realize that I was suffering from multiple disorders, for decades before I got COVID, all of which have been identified as signs of probable low-grade thiamine deficiency or defects in thiamine metabolism.

There is no single thiamine dosing protocol that works for everyone, and so trial and error is called for. This is well known, e.g., in the Parkinsonś Disease community, in which many patients are self-treating with thiamine, with doctor approval, via a trial and error approach and using various forms of thiamine.

Needless to say, there is much more to be said about all this. But in a nutshell, my working hypothesis is now that the vasomotor regulation responsible for the nasal cycle and for proper drainage of the sinuses and eustachian tube in a healthy person was severely impaired, in my case, by the COVID virus, and that I was highly susceptible to a crash of my vasomotor function in the upper respiratory tract through a decades-long subacute/low-grade thiamine deficiency that was affecting me steadily with other disorders, such as severe dry eye, recurrent mouth ulcers, episodes of prolonged fatigue and tachycardia, episodes of vertigo, and episodes of severe anxiety. Every last one of these problems has been studied in relation to thiamine deficiency, and I now take this connection seriously.

Please consider reading as many articles by Dr. Derrick Lonsdale as you can find online (in a range of journals and newsletters), and please tune in to the website operated by Elliot Overton, a British functional medicine practitioner whose specialty is developing and fine-tuning thiamine therapy.

If thiamine turns out to be our solution, we shall be very lucky, because to date, even very high doses of thiamine have not been been associated, across a range of studies, with toxicity. Our ability to absorb thiamine, though, can be impaired after a prolonged subacute deficiency, and so yes, we can experience side-effects, even from lower doses, at the outset of supplementation, but again, but toxicity is essentially unheard of in relation to B1/thiamine (and that is why my primary care internist felt comfortable with my proceeding). Whatś more, some of us improve substantially on doses that are actually quite low. Right now, I take 150 mg/day of allithiamine and a B complex containing 50 mg of thiamine mononitrate. . .AND, per Overton and others like him, I make sure to cushion the thiamine with all the other B vitamins (in complex form) and also with daily potassium bicarbonate (because as oneś metabolizing of thiamine increases, the bodyś demand for this type of potassium seems to increase). Godspeed to you, and please stay hopeful.