Fatigue in systemic lupus erythematosus. Prevalence and relation to disease expression.

Significant fatigue was observed in 63/83 (76%) SLE patients. Patients with fatigue had significantly lower lymphocyte counts (1090 +/- 60 vs 1675 +/- 205 cells/mm3 P = 0.003), and higher ratings for headache, nervousness and musculoskeletal symptoms and signs. These disease parameters also correlate significantly with the magnitude of fatigue. Fatigue correlated with disease activity index (r = 0.49 P < 0.001).