Caccappolo, E, Kipen, H, Kelly-McNeil, K et al. · Journal of occupational and environmental medicine · 2000 · DOI
This study tested whether people with chemical sensitivities, chronic fatigue, and asthma have unusually sensitive noses. Researchers measured how well different groups could smell odors and identify them. While people with chemical sensitivities didn't actually detect odors at lower levels than others, they did report feeling more physical symptoms and found certain smells more unpleasant than other groups did.
Many ME/CFS patients report heightened sensitivity to odors and chemicals, making this finding important: it suggests that chemical sensitivity may involve how the nervous system processes and reacts to odors rather than simply having a more sensitive nose. Understanding this distinction could guide treatment approaches and help validate patients' experiences as involving real physiological differences in perception.
This study does not prove the biological mechanism underlying heightened odor sensitivity in MCS or CFS, nor does it establish causation between odor sensitivity and disease development. The cross-sectional design cannot determine whether altered odor perception predates or results from the condition. Additionally, findings were specific to PEA and may not generalize to all odors or chemical exposures.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
The first block is for the primary paper and is the citation you should use in research work. The atlas-snapshot line only applies if you are specifically referring to this atlas’s reading of the paper on the date shown.
Primary citation
Caccappolo, E, Kipen, H, Kelly-McNeil, K, Knasko, S, Hamer, R M, Natelson, B, et al. (2000). Odor perception: multiple chemical sensitivities, chronic fatigue, and asthma.. Journal of occupational and environmental medicine. https://doi.org/10.1097/00043764-200006000-00012
BibTeX
@article{mecfsatlas-caccappolo-2000-odor-perception,
author = {Caccappolo, E and Kipen, H and Kelly-McNeil, K and Knasko, S and Hamer, R M and Natelson, B and Fiedler, N},
title = {Odor perception: multiple chemical sensitivities, chronic fatigue, and asthma.},
journal = {Journal of occupational and environmental medicine},
year = {2000},
doi = {10.1097/00043764-200006000-00012},
note = {PubMed: 10874656},
url = {https://www.mecfsatlas.com/evidence/caccappolo-2000-odor-perception},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-30. https://www.mecfsatlas.com/evidence/caccappolo-2000-odor-perception
Contribute
Private, reviewed by a human. Not a public comment thread.