Clinical and allergological analysis of ocular manifestations of sick building syndrome

PURPOSE The disease concept of sick building syndrome (SBS) is still unclear. Ocular mucous membrane irritation is one of the major symptoms of SBS. However, the immunological aspects of the ocular complications of SBS are not yet clarified. The clinical and allergological aspects of SBS cases with ocular disorders with special reference to allergic conjunctival diseases (ACD) were analyzed, especially with respect to local immunological features. METHODS Twelve cases of SBS with ocular findings and 49 cases of ACD (allergic conjunctivitis [AC], atopic keratoconjunctivitis [AKC], and vernal keratoconjunctivitis [VKC]) for comparison were evaluated. The clinical findings in SBS and ACD were scored, and tear film breakup time (BUT) was measured. Cytokine (interferon-γ [IFN-γ], interleukin [IL]-2, IL-4, IL-5, IL-6, IL-8, and IL-13) concentrations in tears were analyzed by cytometric bead arrays. Eosinophil count in peripheral blood, total IgE in serum, and multiple allergen simultaneous test (MAST) for antigen-specific IgE were also measured. RESULTS In SBS, conjunctival lesions were observed in all cases, and corneal abnormalities were found in two-thirds of the cases. Limbal lesions were observed in 2 pediatric cases. Mean serum total IgE level in SBS was significantly higher than that in AC; however, it was significantly lower than that in AKC and VKC. Eosinophil count in peripheral blood and number of positive allergens in MAST were significantly lower in SBS than in AKC and VKC. Significant elevation of tear IL-4 was observed in SBS and ACD. However, in contrast to ACD, elevation of other cytokines in tears was not observed in SBS. Mean tear BUT in SBS was in the normal range. CONCLUSION From these results, SBS is thought to be partially induced by an allergic response. However, clinical dissociation of the ocular clinical findings and local immunological features in tear cytokines may suggest that SBS belongs to a different entity from ACD.