1. The best smell test is an olfactory threshold and odor identification test. The second best test is the University of Pennsylvania Scratch and Sniff Test(UPSIT). The third best and easiest to use is the AST (Alcohol Sniff Test). Unwrap an isopropyl alcohol wipe. Ask the patient to sniff and determine that they can identify the isopropyl alcohol odor. With the patient's eyes closed and with normal respiration (i.e. no sniffing and no deep inhalation) slowly move the pad closer and closer to the nose. This can be done from an inferior to superior direction beginning around the mid sternum at 20-30 cm and then slowly moving closer to the nose. Normosmics detect the alcohol at a distance greater than 10 cm. Hyposmics detect the alcohol between 0 and 10 cm and anosmics cannot smell the alcohol. They may feel it (trigeminal), but they cannot smell the isopropyl alcohol. One, 2, 3 or even 4 cm is severe hyposmia.
   
   
2. Prednisone course: 60 mg p.o. q am x 5-7 days.

Smell impairment affects 1–2% of Americans and while it is true that some do not complain, for many it is a significant sensory loss. The majority of food appreciation comes from olfaction. Those who are smell impaired have lost their ability to taste and appreciate the flavors of food. In addition, it represents a health hazard, for they cannot smell smoke, the early warning sign of fire. They cannot smell the odorants placed in propane and natural gas as a warning sign of gas leaks. They cannot detect the odors of spoiled and rotten foods and so are at constant risk for recurrent food poisoning.

Smell testing is not generally available. The alcohol sniff test described above is a very good screening test. The average ENT physician and neurologist is neither skilled nor interested in smell impairment; therefore, individuals often need to be treated by their primary care physician or referred to a center with interest and expertise in olfaction.

For the non demented, the vast majority of smell impairments are caused by inflammatory nasal disease. Other common causes are a sequelae of upper respiratory tract infection or head trauma. Olfactory loss is common in many dementias, most notably in Alzheimer's, and in Parkinson's disease.

The differential diagnosis for smell impairment is lengthy, but for most diseases it is only one of a myriad of signs and symptoms. For the interested physician, there are numerous articles and even textbooks to read.

The suggested ambulatory pathway is reasonable. The prednisone challenge, combined with a history looking for viral, traumatic and inflammatory nasal causes, will lead to a correct diagnosis or reason for referral in the majority of cases.

For those who are smell impaired, the following are the standard recommendations we offer at the UCSD Nasal Dysfunction Clinic.

Special Instructions to Anosmics

Persons who are anosmic should observe some simple precautions.

A smoke detector in the home is important. As a minimum there should be a smoke detector in the kitchen, in every room that might have a fire such as a room with a fireplace, and in every room in which the patient might sleep, i.e. bedroom, den, etc. Smoke detectors can be battery-operated or connected directly into a 110 volt AC current system and can be obtained at most hardware, lighting or other building stores.

An electric stove is preferable to a gas stove, but a gas stove equipped with an automatic pilot improves the safety. Commercial gas detectors are available. If the house uses propane or natural gas, there should be an appropriate gas detector at each location where a gas leak might exist and cause a problem. Propane gas and regular gasoline are heavier than air, and so detectors for these substances should be placed near the floor. Natural gas is lighter than air and rises as does smoke. Detectors for these substances should be placed at high points such as the ceiling, top of the stairwell, etc. Propane detectors are available through propane dealers, recreational vehicle dealers, and marine stores. Natural gas detectors, propane detectors and gasoline detectors are all available through marine facilities.

Care should be taken in preparing food, particularly left-overs, since undetected, spoiled food can be hazardous. When in doubt, discard left–overs or have a family member with a normal sense of smell confirm that the food is not spoiled.