Exacerbation of lymphomatoid papulosis during rituximab therapy.

We report two cases of lymphomatoid papulosis (LyP) occurring in conjunction with B-cell lymphoproliferative malignancies where the LyP was exacerbated during rituximab (anti-CD20 antibody)-based therapy. We postulate that the altered B-cell cytokine milieu acted to allow an exacerbation of the patient's concomitant T-cell disease and discuss the possible mechanisms by which this may have occurred.