Rheumatoid Nodules

Dr Christopher Kelsey MSc MB FRCP, Consultant Rheumatologist, Oldchurch Hospital, Romford
Original article: 26/07/2010
Reviewed: N/A
Next review due: 26/07/2013

What are rheumatoid nodules?

Rheumatoid nodules are firm lumps that appear subcutaneously (ie under the skin) in about 20% of patients with rheumatoid arthritis. These nodules usually occur over exposed joints that are subject to trauma, such as the fingers joints and elbows, though occasionally they can occur elsewhere such as the back of the heel. Occasionally they can become painful and the overlying skin can become infected or even ulcerate.

There is a suggestion that the incidence of rheumatoid nodules is falling but nowadays they are most commonly seen in patients commenced on methotrexate therapy in whom the nodules that develop tend to be small and multiple (micro nodules) most commonly around the finger joints. About 8% of patients on methotrexate develop micro-nodules and we don’t really know why.

Rheumatoid nodules are very firm and under the microscope there are intense inflammatory changes but these are different from the ones that are found within the joints. This explains why disease modifying drugs and biological therapies may not reduce the size of the nodules even though they may have an excellent effect at controlling joint disease.

Who develops rheumatoid nodules?

Patients who develop nodules tend to have more severe disease, are almost invariably rheumatoid factor positive and are more prone to other extra articular (meaning outside of the joint) features of rheumatoid, including vasculitis and lung disease. Very occasionally rheumatoid nodules can develop within the lungs. These are usually asymptomatic (ie you would not experience any symptoms from this), but can cause concern to doctors because of uncertainty about the diagnosis.

What can we do about nodules?

There is little research in this area. Combination disease modifying therapies and the biological therapies seem to have reduced the incidence of nodule formation. If micro nodules develop while on methotrexate then the addition of hydroxychloroquine and other disease modifying drugs including prednisolone may reduce their size. If nodules are small they can be ignored. However, if they are subject to repeated trauma, surgical removal is an option. Occasionally, injection of steroid into or just under the nodule can reduce their size.