Olfactory function in HIV-positive subjects.

The aim of this study was to reinvestigate previous reports of chemosensory dysfunction in HIV-positive subjects. Odor thresholds, odor discrimination and odor identification were assessed using the Sniffin' Sticks test battery. Seventy-four HIV-positive patients were tested. According to CDC criteria, 38 subjects were classified as stage A, 10 as stage B and 26 as stage C. None of the subjects exhibited severe cognitive impairment. Compared to normative data all subjects had normal odor identification and discrimination. However, odor thresholds were well below the median of a normal population. There were no significant differences between stage A, B or C subjects. This may be interpreted as indicating that olfactory dysfunction is among the primary deficits of HIV infection and occurs independently of disease stage. These results confirm previous work suggesting that odor thresholds are elevated early in HIV infection whereas a decline in identification and discrimination abilities is correlated with reduced cognitive abilities.