[Rheumatoid neutrophilic dermatitis]

Rhumatoid arthritis (RA) is a chronic inflammatory joint disease. It appears to be caused by a combination of genetic and environmental factors. It may be accompanied by well-known extra-articular damage (e.g. lung, kidney, heart), while cutaneous involvement such as rheumatoid neutrophilic dermatitis (RND) is much less frequent.

A 64-year-old woman was referred by rheumatologists after she developed a cutaneous eruption on the forearms, elbows and scalp in a setting of progressive RA. A skin biopsy showed a dermal neutrophilic infiltrate throughout its entire thickness as well as leukocytoclasia, with fibrinoid material visible in certain areas. No vasculitis was observed. This histological examination led to a diagnosis of RND. The eruption was successfully treated with topical corticosteroids.

RND is a rare sign in RA that presents clinically as plaques, erythematous nodules or urticarial lesions. The lesions tend to disappear naturally or on treatment of RA. Topical corticosteroids or systemic therapy, in particular dapsone, may be suggested to treat cutaneous damage.