Image type: Rheumatoid nodules
Body site: Hands
Description: Rheumatoid nodules, firm lumps under the skin, often appear near joints affected by rheumatoid arthritis (RA). These growths vary in size, ranging from as large as a walnut to as small as a pea, and not everyone with RA develops them.
While some nodules are mobile, others remain firmly anchored to tendons or fascia beneath the skin. Common areas of occurrence include the hands, fingers, knuckles, and elbows. In some cases, they may form on the vocal cords, leading to hoarseness, or within organs like the lungs and heart, potentially impacting their function.
While many individuals with RA experience no issues from nodules, others may find them painful and restrictive, as they can compress nerves and restrict movement. It is essential for patients experiencing difficulties to collaborate with their doctors to explore treatment options and alleviate symptoms.
Causes: The development of rheumatoid nodules is commonly associated with severe RA with nearly all cases occurring in individuals who have elevated levels of “rheumatoid factor” in their blood. Furthermore, certain factors may exacerbate the likelihood of these nodules appearing. Research indicates that smoking is correlated with an increased incidence of nodules in individuals with RA. Additionally, methotrexate, a frequently prescribed drug for RA management, has been implicated in the formation of rheumatoid nodules.
Diagnosis: Subcutaneous nodules in a patient with a known history of RA usually present a clear diagnosis. However, to establish a definitive diagnosis, a deep 4-, 5-, or 6-mm punch biopsy or incisional biopsy that includes the subcutis is necessary. The histological findings are typically diagnostic, but in rare cases, it may be difficult to differentiate from subcutaneous granuloma annulare.
If the patient does not have a known history of RA, an initial screening evaluation may include X-rays of joints with evidence of arthritis, rheumatoid factor, complete blood count (CBC) to check for anemia and/or thrombocytosis, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and screening antinuclear antibody (ANA) (approximately 25% of patients with rheumatoid arthritis will have a positive ANA).
Treatment
The primary approach to treating rheumatoid nodules involves managing the underlying RA. While not always effective, these lesions typically diminish gradually with appropriate RA treatment.
Initially, nonsteroidal anti-inflammatory drugs (NSAIDs) may be prescribed, either alone or in combination with low-dose prednisone. If a patient shows inadequate response to this therapy, immunosuppressive medications such as methotrexate, hydroxychloroquine, minocycline, cyclosporine, and biologic agents may be considered. It is important to note that paradoxically, methotrexate and biological agents have been reported to exacerbate rheumatoid nodules.
For patients with large lesions causing interference with daily activities, surgical excision may be an option, although recurrence of lesions is possible. Alternatively, injection of large lesions with 10 to 40 mg/mL of triamcinolone is another treatment approach.