The evaluation of abnormalities of smell requires a multidisciplinary approach requiring the involvement of specialists such as internists
, ear-nose-throat physicians, neurologists, allergists, and others.
Various factors in the history can cause abnormalities in the sense of smell. Head injuries and viral infections can produce a sudden change. Whereas, with allergic rhinitis (seasonal allergies), nasal polyps, or tumors the onset is more gradual. Intermittent alteration of smell is often seen with allergic rhinitis. Headaches and behavioral problems suggest there may be a neurological problem. Certain occupational exposures or medications could cause this.
Careful examination of the nasal cavity and sinuses by an ear-nose-throat physician, a detail neurological exam by a neurologist
, and careful exam by an allergist are all important in the evaluation. There are various diagnostic testing modalities. Various chemosensory tests are "threshold tests" which determine the minimum concentration of a substance that can be smelled. Imaging, such as an MRI
or CT scan, to evaluate the brain, soft tissues, and/or sinuses may be indicated. Laboratory testing may be indicated depending on your physical examination. Treatment would be directed at the underlying cause.
It is not possible to come to a diagnosis and treatment plan without examining the patient. The strong recommendation is therefore to get a referral to an ear-nose-throat physician and get evaluated in person.