Multiple chemical sensitivity syndrome in Sjögren's syndrome patients: casual association or related diseases?

Multiple chemical sensitivity (MCS) is defined by multiple symptoms, affecting multiple organs, that wax and wane in response to varying chemical exposures at or below previously tolerated levels. Sjögren's syndrome (SS) is a common autoimmune disease affecting 3% of women aged over 55 years. Except for keratoconjunctivitis sicca (which is associated with SS not MCS), systemic features are common between the 2 diseases, leading to considerable morbidity and, occasionally, mortality. The authors report 3 cases of association between SS and MCS. Three women who were diagnosed with SS showed MCS symptoms and also were diagnosed with MCS. Further studies are needed to understand physiopathogenic mechanisms that eventually may be revealed as common to the 2 syndromes.