Mesalazine-induced lupus.

We report a case of lupus induced by mesalazine therapy taken for over a year for Crohn's disease. The patient had polyarthritis, alopecia, lymphoneutropenia, antinuclear factors, anti-histone antibodies, anti-Sm and anti-RNP. Discontinuation of mesalazine was followed by rapid resolution of the joint manifestations, alopecia and lymphoneutropenia; the anti-histone antibodies fell to undetectable levels and the titers of the other auto-antibodies decreased gradually.