Joint symptoms and diseases associated with moisture damage in a health center

Rheumatic diseases do not usually cluster in time and space. It has been proposed that environmental exposures may initiate autoimmune responses. We describe a cluster of rheumatic diseases among a group of health center employees who began to complain of symptoms typically related to moldy houses, including mucocutaneous symptoms, nausea and fatigue, within a year of moving into a new building. Dampness was found in the insulation space of the concrete floor below ground level. Microbes indicating mold damage and actinobacteria were found in the flooring material and in the outer wall insulation. The case histories of the personnel involved were examined. All 34 subjects working at the health center had at least some rheumatic complaints. Two fell ill with a typical rheumatoid factor (RF)-positive rheumatoid arthritis (RA), and 10 had arthritis that did not conform to any definite arthritic syndrome (three met the classification criteria for RA). Prior to moving into the problem building one subject had suffered reactive arthritis, which had then recurred. Another employee had undiagnosed ankylosing spondylitis and later developed psoriatic arthritis, and another developed undifferentiated vasculitis. A total of 16 subjects developed joint pains, 11 of these after beginning work at the health center. Three subjects developed Raynaud's symptom. Fourteen cases had elevated levels of circulating immune complexes in 1998, 17 in 1999, but there were only three cases in 2001, when the health center had been closed for 18 months. The high incidence of joint problems among these employees suggests a common triggering factor for most of the cases. As some of the symptoms had tended to subside while the health center was closed, the underlying causes are probably related to the building itself and possibly to the abnormal microbial growth in its structures.