Enhanced pain perception in rheumatoid arthritis: novel considerations.

Enhanced pain perception is common among patients with rheumatoid arthritis (RA). Given the putative role of proinflammatory cytokines in the development of hyperalgesia, a greater understanding of factors that facilitate increased cytokine expression in RA stands to increase understanding of the sources of enhanced pain perception. Patients with RA have significantly greater stress-induced proinflammatory cytokine release. Although absolute deficiencies in cortisol have not been demonstrated, functional abnormalities have been described, including "abnormally normal" cortisol levels in the face of increased inflammation and deficient responses to stressful challenges. Parasympathetic insufficiency has also been demonstrated, which may enhance pain perception indirectly through disinhibited cytokine expression. Several psychological variables have also been demonstrated to affect pain perception in patients with RA. Identification of factors that contribute to enhanced pain perception in RA may aid in the development of novel analgesic strategies that, in turn, may decrease disease activity and improve general clinical outcomes.