No sense of smell

Q My husband has totally lost his sense of smell and nearly all his sense of taste. His condition is probably due to many years of inhaling oilpaint fumes and turps as an artist. He no longer uses these. He has been to ear, nose and throat specialists, and has tried several alternative treatments, including homoeopathy, acupuncture and electrical gem therapy – but to no avail. Do you know of a treatment that may work? – Carolle Easton, via e-mail

A Our sense of smell tends to deteriorate as we age, and such olfactory system disturbances are more common in the general population than we would think. According to the US National Institute on Deafness and Other Communication Disorders, over 200,000 people visit a physician each year to seek help with a sense of smell disorder or related problems.

Anosmia – medicalese for no sense of smell – not only has significant debilitating effects on quality of life, but also comes with certain risks. For example, an anosmic person would be unable to smell the smoke from a fire or leaking gas, or identify rotten food and drink, which could result in food poisoning.

The loss of smell is often linked to taste disturbances. In your husband’s case, his sense of taste seems to be intact as he is still able to distinguish the different tastes in food (sweet, sour, spicy). What may be confused with the taste of food is its flavour, which is determined by its aroma, or smell.

It is essential to accurately pinpoint the cause of your husband’s anosmia, as the outcome depends on its aetiology.

The most common cause of anosmia is a physical obstruction (such as swelling or inflammation) of the olfactory pathway because of intranasal polyps, chronic sinusitis or allergic rhinitis. These conditions can all be brought on by allergies which, in turn, may be linked to chemical sensitivity.

WDDTY panellist and allergy specialist Dr John Mansfield has treated many patients whose loss of taste and/or smell had one of two causes. When anosmia is accompanied by a year-round rhinitis (a runny nose), it’s almost always caused by an allergy, he says – to dust, dustmites, moulds, foods, chemicals or fungi. It may well be that the long-term chemical insult has worsened an allergy to a substance other than the paint products themselves.

If your husband doesn’t have a runny nose, and his loss of smell is indeed due to chemical sensitivity, his symptoms may not be necessarily the result of permanent damage, but of continued exposure to the chemical in question. It’s well to remember that oilpaints and turpentine, as well as perfumes, formaldehyde, phenols and petrol, are all hydrocarbons derived from gas and oil. Your husband is also likely to be exposed to them through gas or oil central heating and/or cooking, carpets and chipboards (formaldehyde), soft plastics (phenols) and petrol, as well as via fragrances and toiletries (perfumes). Intermittent exposure to these hydrocarbons tends not to produce symptoms, whereas continued exposure will.

Dr Mansfield suggests that you get a device for measuring the levels of nitric oxide in your air indoors to see if levels are high from your cooker or central heating. Or wait for warmer weather, then turn off your gas utilities and open up all your windows for a week, and see if your husband’s condition improves. Another possibility is a skin test to identify sensitivity to gas, petrol, diesel, phenols or formaldehyde.

If your husband is clearly shown to be hydrocarbon-sensitive, the best course of action is to replace your gas cooker with an electric one and, if possible, move your gas heating system outside, and have him undergo a neutralisation/desensitisation programme. You should also avoid all such chemicals in your toiletries (see WDDTY vol 15 no 5 for more details).

According to our panellist Dr Jean Monro, a chemical-sensitivity expert at the Breakspear Hospital in the UK, people with allergies – including those who lose their sense of smell – often suffer from a zinc deficiency. “Increasing zinc intake could help ease the allergy and help alleviate the problem,” she says. There is also evidence of the importance of zinc in maintaining the senses of both smell and taste (Ann Intern Med, 1983; 99: 227-39).