Phantosmia is smelling odors that aren’t really there. They are considered “olfactory hallucinations”, and seem to occur with neurological disorders. In my case, when the disparity between T3:T4 was too great, my sinus area and eyes would become very very dry and painful, and the phantosmia was directly related to this and my other symptoms. The odor I detected was very characteristic, and often smelled like cigarette smoke, or a burning smoke smell, progressing to a “chemical like smell” or “solvent smell”.
I could empathize with people who experience multiple chemical sensitivities after going through this; living with this full time would have been horrible. In my case, these symptoms waxed and waned in direct relationship to my other TH-responsive symptoms, and so I could use this as well to monitor where I was at. I didn’t experience this symptom at all when I was on an appropriate dose of TH, and when I didn’t have too much disparity between T3/Iodine and T4 when I was not. In particular, when the sinus “dryness” and numbness, along with dry eyes increased, this symptom increased as well.
One thing I’d like to mention is that I believe the word “Phantosmia”, which literally means “phantom” smells, or “smells that aren’t really there”, is very much a misnomer. The “odors” aren’t “phantoms” or “made up” at all. I believe they are a very real phenomena, most likely based on biochemical reactions and/or autoimmune/hypersensitivity reactions going on within the olfactory part of the brain. My “phantosmia” was very much a part of my overall CNS symptoms, and waxed and waned with my “encephalopathy” like symptoms. The nidus, or “focal point” of these encephalopathy symptoms were very much located around my eyes and sinuses, which is right where the olfactory bulb and nerves are located. In turn, my CNS symptoms were very much in sync with, and waxed and waned, with many of my other symptoms I’ve discussed in this website. In particular, when I was feeling the “thymus pain and inflammation” – a dry, almost “burning” or “inflammation” sensation right around my thymus gland and hilar lymph nodes, I would feel this same dry “burning and inflammation” around my eyes and sinuses, often accompanied by this phantosmia. This lead me to feel that many times this phantosmia was a part of the overall autoimmune reaction I was experiencing. This autoimmune reaction could have been related to the anti-thyroid antibodies (TPO, TgAb, TSI), or could have been a hypersensitivity reaction such as a Mast Cell Activation Syndrome, Eosinophilic Disorders, or some other type of “allergic” or “hypersensitivity” response.
The odors that people smell tend to be very characteristic, and in my opinion, are a clue as to the type of potential biochemical reactions going on. In my case, I tended to smell a “cigarette smoke”, or a “burning smoke” or “burning hair” smell, progressing to a “chemical like smell” or “solvent smell”. I felt this could very well have something to do with reactions, biochemical or autoimmune in nature, involving selenocysteines, or sulfur containing thiol groups for example (cysteine/sulfur can smell like “burning hair”). Selenium and cysteine are involved in several important enzymatic functions related to thyroid hormones both in the thyroid gland and in every cell of the body (deiodinases), and are also related to glutathione reactions. Abnormal utilization and breakdown or metabolism, via autoimmune or other mechanisms, of these selenocysteine deiodinases or glutathione problems in the brain near the olfactory bulb could account for the very real cysteine or selenium type odors I was experiencing. On the other hand, disulfide bonds and cysteine are quite common in many proteins, for example, such as within TSH (continual formation and breakdown due to its short half life) and leukotrienes (involved in inflammation in general, and, I suspect, in “autoimmune” inflammation, mast cell activation, etc). Note that antibodies in general are made up of many disulfide bonds (1, 2). Selenium and cysteine are also important components of metaollothioneins (MTs). Metallothioneins are a “family of cysteine-rich, low molecular weight proteins which have the capacity to bind both physiological (such as zinc, copper, selenium) and xenobiotic (such as cadmium, mercury, lead, silver, arsenic) heavy metals through the thiol group of its cysteine residues, which represent nearly 30% of its constituent amino acid residues”. Functional disruptions of MTs would be another aspect to consider in those of us with FQT/FQAD (1, 2), and another possibility in phantosmia as well.
I also discuss how sulfation issues might play a role with secretory cells within the sinus cavities, olfactory bulb, pituitary gland, and hypothalamus in “Additional Mechanisms to Consider”, scroll down to “Sulfation”. This is another potential mechanism to consider with phantosmia symptoms. The olfactory bulb, pituitary gland, and hypothalamus are not only physically located close to each other in the brain, but have functional relationships as well. As a result, neurodevelopmental, reproductive, and smell disorders can occur in a variety of genetic syndromes. The olfactory nerves are in fact, a conduit into the brain via the olfactory mucosa in the sinus cavities and the olfactory bulb in the brain. Bowman’s Glands (which happen to sit within connective tissue), contain cells with large secretory vesicles, and I often wondered if the severe dryness I experienced in my sinuses was due to damage there. Of particular interest to me, is that GnRH is synthesized and released from GnRH neurons within the hypothalamus to stimulate production of the sex hormones FSH and LH from the pituitary gland. Interestingly enough, these GnRH neurons do not originate in the brain, but instead originate from embryonic nasal tissue where they then migrate into the brain along olfactory axon fibers from the nose. A subset of GnRH neurons can even trace their origins to neural crest cells (scroll down to “Cell Lineages” [cranial, trunk, vagal, cardiac] and “Neural Crest Derivatives” [mesectoderm, endocrine, peripheral nerves, melanocytes]). I often wondered if there is still some kind of connection, because whenever I was “high” on TH or estrogen, for example, not only would my sinuses be extremely dry, and phantosmia would occur, but I would feel “pain and pressure” deep to and between and behind my eyes. This would wax and wane depending on how much TH I took, and although I cannot prove this, I started wondering if this “brain pain” was my pituitary gland, as it seemed like the correct location. After all, my thyroid and thymus gland were responding with “pain and pressure” to the same stimuli, so it made sense that my pituitary gland might too. Additionally, for years I had been experiencing what felt like “hormonal pulses” or momentary “surges” in my brain (which could be quite distressing depending on the severity of them). Without going into detail as to how I surmised this, I came to think of them as being pituitary or hypothalamic in origin. This entire website explores how FQ’s appeared to damage my hormonal synthesis or metabolism, and that includes the pituitary gland and hypothalamic roles. From my perspective, all this information can be correlated and considered as a possibility with many of the symptoms I experienced from FQT/FQAD, all discussed throughout this website. And this includes the phantosmia I experienced with a “burning sulfur” smell. I know the many links and topics I’ve provided in this paragraph can be difficult for non science people to grasp, but I feel this information is important to include for those who might want to pursue these aspects in more detail.
For those unfortunate people smelling rotting meat, garbage, or feces, a source to consider for reactions would be the ubiquitous polyamines such as putrescine, cadaverine, or spermidine. Many thiols (organosulfur compounds) emit a variety of strong odors (see Thiols, Odors). Sometimes I felt like I was smelling a “chlorine” smell, which always made me think of a “respiratory burst“, except potentially autoimmune induced (myeloperoxidase using hydrogen peroxide to produce hypochlorous acid/hypochlorites, which I thought of because of the “burning” sensation in my thymus/LN and sinus and eye areas when this occurred). Ammonia smells might bring up additional things to consider on the list. One of the many of the long list of rather familiar side effects of anticholinergics is a “smoking smell”, and I discuss in several places in this website why I believe acetylcholine-related mechanisms were affected in me as a result of the FQ. Really thinking about the type of odor one is smelling may be able to provide clues as to what type of abnormal biochemical or autoimmune reaction near the olfactory bulb may be causing it. Many things can cause phantosmia, and certainly what I am suggesting is potentially only one of many causes. Severe or prolonged cases of it require a neurological workup; however, for many people, phantosmia is thankfully a rather benign passing event and not necessarily cause for concern.
The important point is that at least in some cases (such as my own) I don’t believe these smells are “phantom” at all, but instead are representative of a very real phenomenon going on with our metabolism at the time the smell is occurring. I think they often occur with “neurological disorders” because neurological disorders are real, autoimmune disorders are very real, and both very often go hand in hand with abnormal metabolism of neurotransmitters and other hormones. In my case, normalizing thyroid hormones, and strictly limiting iodine to the “right” amount for me, helped keep all my symptoms at bay, and this included the phantosmia. I have read of people who have taken high dose iodine and gotten a “metallic taste” in their mouth. In my case, “too much” iodine (in the face of certain TH serum levels scenarios) led to my phantosmia of “chemical” and “solvent-like” smell. I often wondered if this was due to iodine reactions going on, either with selenocysteine enzymes or glutathione related enzymes within my CNS.
On my page “Nails: Dry And Brittle With Vertical Ridges On Them” I also discuss how my particular case of phantosmia could be related to my dry brittle nails. Although hair and nails at first don’t seem to have much in common with nasal sinuses or olfaction, both may represent possible abnormalities or dysfunctions with thiols, cysteine, and disulfide bonds in me. It would be interesting to see if any number of correlations among these existed within the FQT/FQAD populations as well as the populations of people experiencing phantosmia, nail disorders, thyroid disorders, autoimmune disorders, or other conditions.
It’s truly unfortunate that for most people experiencing phantosmia, physicians will treat them the same way they treat everyone who has a strange symptom that’s not a known “Top 40 Diagnosis”: they’ll be treated as if it can’t possibly really exist (hence, the name “phantosmia”), and they’ll be blown off as “psych cases”, smelling “phantom odors that aren’t there”, and that it’s “all in their head”. Well, I believe it is in our heads – but that the odors are very real, and can be a valuable clue to help elucidate potential mechanisms of biochemical reactions and potential malfunctions of those. It would be great if researchers (and physicians) would say “How curious, that all these people are smelling these same characteristic common smells, over and over again. What could all these people have in common, other than the phantosmia? How interesting that these smells often accompany other symptoms as well, or occur at certain times, or with certain foods or medications. I wonder what we can learn from this?”
Unfortunately, curiosity, original thinking, and funding are in rather short supply and not encouraged or supported in the medical research sciences unless one is working on the next new big block buster money-making cancer or diabetes drug. So for the milder cases of phantosmia, such as mine, I doubt anyone’s going to figure it out soon or even take an interest in doing so. Which is a shame, because it’s obviously connected to something much bigger than simply “smelling odors that aren’t there”, and I’m sure there would be much to learn from that.