Churg-Strauss syndrome: diagnostic difficulties and pathogenesis.

A 52-year-old woman with a history of chronic obstructive pulmonary disease presented with symmetrical polyarthritis involving her metacarpophalangeal and proximal interphalangeal joints, knees, ankles, and hips and with a purpuric rash involving her lower extremities. She had a history of recurrent episodes of purulent otitis often associated with myalgias and arthralgias. Laboratory studies at presentation included leukocytosis with 16% eosinophils, an elevated rheumatoid factor titer, and an elevated antineutrophil cytoplasmic antibody titer.