Knocking some sense into cystic fibrosis assessment
medwireNews: A deficient sense of smell is significantly more common among individuals with cystic fibrosis (CF) than it is in healthy people, report researchers.
Considering the effect this could have on nutrition and overall therapy outcomes, assessment of olfactory function should be introduced as part of usual CF care, say Jochen Mainz (Jena University Hospital, Kochstrasse, Germany) and colleagues.
In CF, mucosal inflammation and retention of thickened mucus facilitates colonization of the sinonasal space with pathogens, causing frequent symptoms of rhinosinusitis, including an impaired sense of smell, explain the researchers. However, despite probable effects on nutrition and overall health, little is understood about CF-rhinosinusitis, they say.
In an assessment of 35 CF patients using the odor-dispensing devices Sniffin' Sticks (Burghart Medical Technology, Wedel, Germany) the team found that the patients had significantly elevated fractions of smelling impairment compared with 35 healthy controls.
While the majority (62.8%) of healthy individuals were found to have a normal sense of smell, this was diminished in the majority (71.5%) of CF patients, with almost 9% of them having no sense of smell.
"Almost [two thirds] of patients have impaired olfactory function, which not only reduces quality of life, but also increases risk of malnourishment, which can impair pulmonary function, and worsen the overall outcome," write Mainz and colleagues.
Of three smelling characteristics tested, only odor threshold was significantly different between the two groups. CF patients were only able to identify n-butanol at a mean of 2.95 dilution steps, while healthy individuals were still able to identify it at 7.78 dilution steps.
The other two characteristics tested, discrimination ability and identification ability, did not significantly differ between the CF patients and controls, with a mean of about 12 items correctly identified by each group.
"This suggests that the olfactory dysfunction in CF might result from dysfunction at the level of the olfactory periphery due to either problems in conduction and/or a functional lesion due to the inflammatory process," explain Mainz et al.
The team says the findings underline the need to include upper airway assessment into CF routine care with a special focus on olfactory deficiencies.
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By Sally Robertson, medwireNews Reporter