Systemic mastocytosis associated with presence of rheumatoid factor

J. Ritz, M. Geller, J. L. Sims and M. N. Mueller

We encountered a case of systemic mast cell disease associated with rheumatoid factor; to our knowledge, this has not been reported in the literature. Rheumatoid arthritis as an unrelated second disease cannot be excluded, but there is support for a relation between joint symptoms, rheumatoid factor, and the mast cell disease.