Dear Doc: Can allergy be blamed for loss of smell?

Dear Dr. K: I’ve lost my sense of smell. Could this be due to allergy?

The answer to your question is, yes, it could be, but it is unlikely. I say that because on your recent visit here your allergies were under excellent control and the only time I’ve seen anosmia (loss of sense of smell) from allergy is when it is severely out of control.

A complication of allergy that frequently causes anosmia is nasal polyposis. Treatments of the polyps via nasal sprays and/or surgery usually returns the sense of olfaction (smell).

Placebo effects have a cousin: Nocebo

The American Journal of Medicine had a recent review article titled, “Placebo: The Good, the Bad, and the Ugly.”

Placebo effect is defined as any improvement in discomfort or illness resulting from an intervention possessing no physical effect. Historically, the best research techniques always include a placebo control group and double-blinding — that is, neither the researchers nor the study patients know which group is which until the study is completed. Interestingly, surgery and physical manipulation of the body, such as physical therapy and chiropractic, have greater placebo benefit than oral medication.

Such properly conducted research has led to the realization that there also exists a “nocebo” effect, which is symptoms or illness resulting from expectations or fears of a bad effect. (Kind of like reading a list of possible adverse side effects from a medicine and thinking you are experiencing some of the symptoms.)

Both the placebo and nocebo effects can occur as a “take-away” from the benefit of a traditional therapy, or can stand alone from an inert therapy.

The nocebo effect also is why all drug trials demonstrate significant rates of undesirable side effects in the control group. These negative reactions are felt to come from the individuals’ innate pessimism or tendency toward depression.

Azithromycin helps prevent COPD set-back episodes

A study outlining the use of weekly azithromycin for COPD patients with frequent exacerbations was published recently in the world’s leading general medical journal, Lancet. “Frequent” was defined as three or more episodes in a year of these episodes of sustained worsening of these patients’ conditions.

Several cogent reasons warrant attempting to prevent these exacerbations. First and foremost, they make the patient sick and can lead to hospitalization, and sometimes to death. Also, each exacerbation can worsen the overall degree of lung impairment, kind of a racheting down in lung function. The patients in the year-long Lancet study were treated with 500 mg. a day of azithromycin for the first three days of each week.

This particular drug was chosen because it has immunomodulatory properties. That is, it works not only as an antimicrobial, but also as an anti-inflammatory. It is concentrated 200 times in the white blood cells, which go to the bronchial tissues. It also has a long half-life of about 70 hours after a dose.

Patients in the trial had 58 percent fewer exacerbations.  Additionally, this benefit lasted for more than six months after the drug was stopped.

Eew! Helminths (worms) go viral

Are you having trouble with recurrent viral infections? Perhaps it’s because you also have a worm (helminth) infection. Immunology research recently published in Science suggests that.

Parasitic worms are strong activators of T-helper cell 2, a lymphocyte that then produces cytokines that can help kill helminths, but that also turns off production of the cytokine interferon, which is a mainstay for fighting viruses. Helminths also reprogram the macrophages (“big eaters”), a type of white blood cell, so that they fight the worms, but totally ignore viruses.

This double whammy on the immune system’s ability to fight viruses can lead to reactivation of latent viruses such as herpes or shingles, but also to greater chance of catching new viruses.

This latter issue especially applies in third-world areas where worm infestation is common, and along with HIV and Ebola viruses.

New entry for the “Don’t text and drive” list

Believe it or not, the greatest increase in anosmia is coming from texting! This stems from the dramatic increase in “rear-ender” automobile accidents due to texting while driving. The whiplash injury frequently seen in these mishaps causes disruption (tearing) of the olfactory nerve as these fibers pass through the cranial bone into the nasal chamber.

Other neurologic problems that can cause loss of smell include meningitis, benign and malignant brain tumors in the frontal lobe area, and cerebral artery aneurysms. Finally, loss of sense of smell can occur as an early sign of Parkinson’s disease.

Going back to the allergy question, a very common cause of anosmia is chronic use of nasal decongestants such as Afrin, Neo-Synephrine and four-way nasal sprays. These medicines work by constricting blood vessels in the nasal membranes, and when used for protracted periods can lead to vascular injury to the delicate olfactory nerves.

Infections are another common anosmia cause; simple colds often cause a decrease in the sense of smell. Some viral and bacterial infections, however, can cause a more severe and protracted effect on smell sensation via toxicity to the olfactory nerves.

Also, certain molecular deficiencies can cause the loss, most notably low serum zinc levels and low vitamin B12 levels.

Finally, certain volatile chemical agents can cause loss of smell through either low-grade, long-term exposure or through accidental high-dose toxic exposure.

Few victims, but plenty of chances to ingest

Heads up. This article is truly only intended for a very, very select group of individuals with severe food allergy. It addresses a very special situation when foods are found as an excipient (non-active ingredient) in a medication.

Excipients are added in manufacturing to protect, support or enhance stability or bioavailabilty of an active ingredient.

The amount of food found as an excipient is truly miniscule, and therefore, 99.99-plus percent of people actually allergic to that given food would not – repeat NOT – be affected by the tiny amount found in the medicine.

Some medicines that contain trace amounts of egg include: Interferon, some probiotics, vaccines against flu, measles-mumps-rubella (MMR), rabies and yellow fever; Propofol, Ibuprofen, some multi-vitamins, Rosiglitazone and diphenhydramine.

Tiny amounts of fish protamine are found in NHP insulin.

Gelatin is found in many capsules and tablets, and in some suppositories and nicotine chewing gum. Vaccines for flu, Japanese encephalitis, MMR, rabies, tick-borne encephalitis, typhoid, varicella, yellow fever and zoster also contain it.

Milk has four allergy-causing proteins: Casamino acids are found in vaccines (DTaP, meningococcal pneumococcal, Td). Casein is found in Cefditoren, Miconazole, some probiotics and vaccines (TDaP, typhoid). Lactalbumin is found in the oral polio vaccine. And lactose is found in many tablets, capsules and granules. It is also in some asthma inhalers: Foradil, Advair, Flovent, Ventolin, Pulmicort, Spiriva, Symbicort and Asmanex.

Peanut oil is found in dimercaprol injection, progesterone capsules and valproric acid capsules.

Pine nut resin is found in fluoride tooth varnish.

New Intranasal Therapies

New nasal spray help on the way. Three new nasal therapies for allergic rhinitis appear to bring “new help to the table.”

The first two are propellant-delivered intranasal steroids: QNASL, which delivers beclomethasone; and Zetona, which delivers ciclesonide. The same two medicines have been available in aqueous solution sprays.

The welcome difference is the improved delivery mechanism. Many people find the aqueous forms problematic because they drip down the throat, or they don’t seem to have enough oomph to get up in- to the congested areas. The new propellant devices use a chloroflurocarbon (CFC)-free puff that doesn’t drip and is mighty enough to get past the congestion (and doesn’t damage the ozone layer).

Additionally, a “first” among nasal sprays is now available – a combination spray. Dymista provides a topical steroid (Fluticasone) with a typical antihistamine (Azelastine). There seems to be a symbiotic benefit in combining the two classes of medicine into a single spray, especially in individuals who get an inadequate response to single-entity therapy. For now, the combo comes in an aqueous spray format.

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