[Does methotrexate induce "rheumatoid nodules"? Case report and discussion of the literature]

A 58-year-old woman with chronic polyarthritis rapidly developed a large number of rheumatic nodules under treatment with methotrexate. A comparison with other cases reported to date showed that the sudden onset of such nodules after initiation of treatment, and their disappearance again after discontinuation of the drug make the causal relationship highly likely. Although the predominantly anti-inflammatory actions of methotrexate control the chronic polyarthritis in almost all cases so far reported, they are unable to prevent the primarily immunological tissue necrosis (rheumatic nodules) and may even promote their development through the liberation of adenosine. Only in very rare cases does the severity or localisation of the nodules--e.g. vasculitis, pulmonary or cardial manifestation--necessitate the discontinuation of methotrexate.