Rheumatoid nodules


Rheumatoid nodules are subcutaneous masses occurring in rheumatoid arthritis, usually at sites of repeated trauma, e.g. hands and elbows but also ankles, and often in patients being treated with methotrexate. They are usually non-tender but can interfere with manual activities and may become ulcerated by rubbing e.g. against the heels of shoes, leading to ulceration and bleeding.   Medical treatment is often not successful so intralesional steroid injection or excision may be necessary. 

Histologically, they are composed of central fibrinoid necrosis surrounded by a palisade layer of histiocytes and a peripheral zone of loose connective tissue.