Fibromyalgia in lupus erythematosus

Fibromyalgia has been reported to occur with high prevalence in systemic lupus erythematosus. Data on fibromyalgia in other subsets of lupus erythematosus are not available. Risk factors for fibromyalgia have not been defined. We investigated 60 patients with different subsets of lupus erythematosus for the presence of fibromyalgia, association with clinical and laboratory parameters and disease activity. Our data were compared with the multicentre lupus erythematosus registry at the Free University of Berlin. Ten out of 60 patients with more than 11 tender points and widespread pain for more than 3 months were classified as positive for fibromyalgia. All of them were female. Fibromyalgia-positive patients suffered significantly more often from headache, morning stiffness, diffuse alopecia, muscle pain, arthralgia, renal involvement, and disclosed peripheral blood cell cytopenia, rheumatoid factor, hypergammaglobulinaemia and intake of corticosteroids and azathioprine. Fibromyalgia was more frequent in systemic lupus than in other lupus subsets. Evaluation of fibromyalgia symptoms and lupus disease activity was performed in 30 patients in a 1-year (range 9-13 months) follow-up. These 30 patients consisted of 9 fibromyalgia-positive and 21 fibromyalgia-negative patients. Both groups were characterized by stable clinical features such as number of tender points and ECLAM index. Fibromyalgia did not show a correlation with lupus activity. We suggest that fibromyalgia and lupus erythematosus are distinct complaints. Patients with lupus are at risk of developing secondary fibromyalgia. The clinical features of fibromyalgia-positive patients may contribute to misinterpretation of lupus activity.