Changes in the sense of smell may be quantitative and qualitative, or possibly even a combination. Quantitative changes may manifest themselves partly as hyperosmia and partly as hyposmia, although hyposmia is much more common. Qualitative changes are segignated a parosmia. Disosmia is a condition in which stimulation of the sense of smell does not result in an adequate olfactory impression, but rather in a distorted sensation, usually unpleasant. The precise mechanism and etiology of parosmia remain to be classified.
Recent molecular biological advances enable us to a more accurately assess the prognosis for parosmia or suggest more successful treatment. We present an overview of modern classification or definition of parosmia and related clinical issues requiring greater discussion. We collected 94 parosmic patients from 9 dysosmia clinics and discussed them in this reports.
Women over 40 years old are most susceptible to parosmia. Upper respiratory viral disease including common cold, head trauma and also zinc deficiency, are conditions that put patients at high risk for parosmia. About 6% of all patients seen at dysosmia clinics have parosmia. We classified parosmia patients by sites, etiology, and severity.
Sites are usually the site of responsible for hyposmia or anosmia. Parosmia patients were divided into organic and functional. The organic type was divided into peripheral, central and mixed peripheral and central. The functional type includes the psychological disorder such as illusions of smell, olfactory hallucination, and the uncinates fits. Etiology was classified as sinonasal disease, upper respiratory disease, head injury, other or miscellaneous. Other categories includes zinc-deficient and drug-inducced. We classified severity as slight, moderate, or severe. Twelve factors, including gender, age, and duration, affect the prognosis of parosmia. We summed up the score for these factors and judged severity. For sever parosmic patients, medical treatment such as medication, local treatment, or surgery must be considered. Major tranquiraizer and surgery should be selected for patients with severe or intractable parosmia.
