Fig 3. Rating of odor intensity (A) as well as hedonic (B) and irritating odors (C) by patients with multiple chemical sensitivity (MCS) (n = 10) and controls (n = 6) after olfactory stimulation.

Abbreviations: D1, γ-undecalactone and concentration level 1; D4, γ-undecalactone and concentration level 4; E1, skatole and concentration level 1; E4, skatole and concentration level 4; and NO, non-odorant. Numbers in parentheses in column 1 indicate the order of the six repetitions (1–6). Statistically significant differences between groups are indicated: *p < 0.05.