Investigation of chemosensitivity during and after an acute cold

Viral rhinitis (the "common" cold) is a frequent worldwide disease. Olfactory dysfunction is one complication that arises during infection, which in most cases heals up spontaneously upon recovery, whereas in some cases it may persist as a partial or total loss of olfaction. The aim of this prospective study was to investigate the change of other chemosensory systems during a cold.

Fifty-eight patients (age 18 to 69 years) with an acute cold were compared to a healthy control group (n = 59; age 19 to 63 years). All patients were examined on 2 occasions separated by approximately 4 weeks. Orthonasal, retronasal, gustatory, and trigeminal nasal function were investigated. Furthermore, ratings of real foods, in terms of intensity and pleasantness, were obtained.

Compared to the control group, patients showed a decreased orthonasal (threshold and discrimination) and retronasal function. Furthermore, patients exhibited a decreased sensitivity to salt and a reduced ability to localize menthol, indicating a decreased taste and trigeminal function, respectively. Upon recovery from the infection, orthonasal olfactory and trigeminal sensitivity increased, whereas retronasal sensitivity showed no improvement and salt sensitivity decreased.

This comprehensive study provides empirical evidence that chemosensory impairment is prevalent during a cold, and additionally shows for the first time that chemosensory features associated with food consumption persist postinfection.