Skin manifestations of rheumatoid arthritis.

Rheumatoid arthritis is a chronic systemic disease that, in addition to articular involvement, may exhibit a variety of extraarticular manifestations. The skin is frequently involved mainly in the most severe forms of the disease. Rheumatoid nodules, accelerated rheumatoid nodulosis, rheumatoid nodulosis, Felty syndrome, rheumatoid vasculitis, pyoderma gangrenosum, rheumatoid neutrophilic dermatosis, interstitial granulomatous dermatitis, and palisaded neutrophilic granulomatous dermatitis are reviewed both clinically and histologically. Moreover, cutaneous reactions related to treatments of rheumatoid arthritis, in particular to biologic agents, are described. Early recognition of these entities through a clinical and histological correlation permit to optimize the management of patients.