What looks like rheumatoid arthritis, feels like rheumatoid arthritis, but isn’t rheumatoid arthritis? Palindromic rheumatism.

First described in 1944 as a "new, oft-recurring disease of joints" (Arch. Intern. Med. 1944;73:293-321), palindromic rheumatism is similar to rheumatoid arthritis in that its characteristic features include pain, inflammation, and disability in and around one or multiple joints that lasts from a few hours to several days. Unlike the symptoms of RA, however, these idiopathic symptoms subside completely between episodes with no residual articular effects. The symptom-free periods can last from weeks to months, according to Dr. Carlo Maurizio Montecucco. "The frequency of acute attacks is variable, ranging from less than one every other month to one every other day, and patients rarely present with constitutional symptoms or fever," he said.

In this column, Dr. Montecucco discusses the pertinent diagnostic and treatment considerations for the management of palindromic rheumatism.

Rheumatology News: What are the key considerations that differentiate palindromic rheumatism from RA or other inflammatory joint conditions?

Dr. Montecucco: Differentiation from RA is quite easy based on the medical history and the characteristics of the arthritis. Differential diagnosis may be more difficult, however, with respect to other remitting/recurrent rheumatic complaints such as crystal arthropathies, Behçet’s disease, reactive arthritis, relapsing polychondritis, familial Mediterranean fever, and other autoinflammatory diseases.

RN: How is the condition diagnosed?

Dr. Montecucco: Palindromic rheumatism should be suspected after a several-month history of brief, sudden-onset, and recurrent episodes of monoarthritis or soft-tissue inflammation with three or more joints involved in different attacks and direct observation of one attack by a physician. The condition can be diagnosed after exclusion of other arthritides, in particular crystal deposition diseases. No single test can confirm a diagnosis. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels are usually within normal limits or slightly elevated; rheumatoid factor (RF), anti–citrullinated peptide antibodies (ACPAs), and antinuclear antibodies (ANA) may be positive in 30%-60% of the cases. Ultrasonography and magnetic resonance imaging (MRI) may show transient synovitis and subchondral bone edema during an attack, but these features are difficult to catch and not specific. No erosions are present on radiographs.

RN: Does palindromic rheumatism every progress to RA, and if so are there telltale signs to identify which patients might be more likely to develop RA?

Dr. Montecucco: Progression to RA occurs in about one-third to one-half of the patients. The latency period between the onset of palindromic rheumatism and the development of RA is highly variable, ranging from a few weeks to more than 10 years. Most progressors have ACPA in their baseline serum, so that ACPA-positive palindromic rheumatism may be regarded as a prodromic phase of RA. Additional factors associated with the development of RA are RF positivity, involvement of proximal interphalangeal joints or wrist, and female gender.

RN: How is the condition treated?

Dr. Montecucco: No randomized controlled clinical study has been done to date. According to several observational studies, and our experience as well, hydroxychloroquine may be effective in reducing the frequency and severity of the attacks and probably also in delaying the evolution to RA. ACPA-positive patients should stop smoking immediately. Nonsteroidal anti-inflammatory drugs are usually effective during painful attacks.