Loss or reduced sense of smell a common problem

Many people don't realize they are losing their
ability to smell because it's a gradual process.

Most patients who have a reduced ability to smell or detect odors seem to attach less importance to the sense of smell in their daily lives than people with a normal olfactory function, according to a report in the April 2011 issue of Archives of Otolaryngology – Head & Neck Surgery, one of the JAMA/Archives journals.

"Disorders of the sense of smell are common," the authors provide as background information in the article.

"In the general population, hyposmia [reduced ability to smell] varies from 13 percent to 18 percent and anosmia (total loss of olfactory function) from 4 percent to 6 percent. The main causes of olfactory disorders are viral infections, head trauma, sinonasal disease, and neurodegenerative diseases."

Most cases of reduced or loss of the sense of smell seem to be associated with aging, according to the authors. They suggest that many patients do not seek medical help for these disorders because they either do not notice the impairment because they do not use the sense or because it develops so gradually that they find ways to cope and adjust.

People with such disorders often complain about difficulties cooking, a lack of appetite and low interest in eating. However, reduced ability to detect odors also can pose an increased risk of hazardous events.

"Approximately 17 percent to 30 percent of patients with olfactory disorders report a decreased quality of life, including symptoms of depression."

Ilona Croy, M.D., and colleagues from the University of Dresden Medical School, Dresden, Germany, evaluated data from 470 individuals (235 patients with a reduced or no sense of smell and 235 individuals with a normal sense of smell) to compare the importance of olfaction in daily life.

The study participants completed the Individual Importance of Olfaction Questionnaire (IO) and olfactory testing using the "Sniffin' Sticks" test kit.

The questionnaire included items to reflect emotions, memories and evaluations that are triggered by the sense of smell; how much a person uses his or her sense of smell in daily life; and how many people use their sense of smell for decision making.

The "Sniffin' Sticks" test kit consists of pen-like odor dispensers that were placed close to the participant's nostrils for a few seconds to assess odor identification ability.

"The main result of the present study is that patients with olfactory disorders rate the importance attached to their olfactory sense to be lower in general and also in all the investigated subscales compared with healthy normosmic subjects," the authors report.

"…Although they might not be aware, [they] seem to adjust to their olfactory constraints. Their sense of smell seems to be of less importance to them in daily life when it is reduced. So they report fewer olfactory-triggered emotions and memories, which seems reasonable because patients with olfactory disease experience fewer olfactory triggers. In accord, they also report to use their sense of smell less and to rely less on this sense in decision making."

"In conclusion, most patients attach less importance to their current sense of smell in daily life than do normosmic individuals and adjust to their reduced olfactory function. This behavior might be an example of regaining psychological health despite acquired and long-lasting impairments," the authors write.

Source: JAMA and Archives Journals