Observations
Typical lesions of erythema elevatum diutinum developed in a 72-year-old patient with IgA paraproteinemia; the condition predictably flared whenever IgA levels reached a threshold of 8 g/L. After 8 years of unsuccessful treatment with various agents, we instituted a trial of PLEX during an acute flare. Following 6 exchanges over a period of 2 weeks, the IgA level decreased from 8 to 2 g/L and the skin lesions cleared. Three weeks later, new skin lesions developed and the IgA level had rebounded from 2 to just over 8 g/L. A second course of PLEX was administered, with excellent results, and a 3-month course of oral chlorambucil (2 mg/d) was initiated. The patient's condition remained in clinical remission for 10 months. Over the ensuing 9 years, she suffered 11 further flares, each of which was associated with IgA levels of 8 to 10 g/L and each responding dramatically to 3 to 5 PLEXs followed by a consolidative dose of intravenous cyclophosphamide (250-500 mg).

Conclusion
We believe that PLEX may have an important role in the management of severe erythema elevatum diutinum associated with monoclonal paraproteinemia refractory to other therapy.

Arch Dermatol. 1996;132:1360-1364