In "Comparison of Patients With Chronic Fatigue Syndrome, Fibromyalgia, and Multiple Chemical Sensitivities,"1 Buchwald and Garrity's data and analysis are weakened by their definition of multiple chemical sensitivity (MCS), which is based on a most atypical choice of "typical" symptoms. The four "respiratory complaints characteristic of MCS"1 that they selected for comparison purposes—from an outdated article with an anti-MCS bias2—were reported by only 22% to 47% of their patients with MCS. The four (unreferenced) neuropsychological symptoms they selected showed a better correlation—two at 67% and two at 90%—but even these fall short of the hallmark correlations that define fibromyalgia (FM) (97% with myalgia) and chronic fatigue syndrome (CFS) (100% with chronic fatigue).
In keeping with the Cullen3 definition cited by Buchwald and Garrity, the hallmark symptom of MCS that the authors should have included in their prevalence analysis (Table 21) is "sensitivity to multiple
Ziem G, Donnay A. Chronic Fatigue, Fibromyalgia, and Chemical Sensitivity: Overlapping Disorders. Arch Intern Med. 1995;155(17):1913. doi:10.1001/archinte.1995.00430170109016