American Board of Internal Medicine (ABIM) Certification Practice Exam

Which of the following is a common characteristic of reactive arthritis?

1. Oligoarthritic joint involvement

2. Symmetrical arthritis in the upper extremities

3. Severe systemic symptoms

4. Increased joint fluid production

The correct answer is: Oligoarthritic joint involvement

Oligoarthritic joint involvement is a hallmark characteristic of reactive arthritis. This condition typically entails inflammation of two to four joints, which can often be asymmetrical. The joints most commonly affected include the lower limbs, particularly the knees and ankles, while involvement of upper extremity joints is less common. In contrast, symmetrical arthritis is more characteristic of rheumatoid arthritis rather than reactive arthritis. Severe systemic symptoms such as high fever and significant malaise are more typical of infections or other inflammatory diseases but are not central to reactive arthritis. While reactive arthritis can lead to some joint effusion, it is not known for increased joint fluid production as a defining characteristic. Instead, the Joint fluid analysis in reactive arthritis is often unremarkable and does not typically show features like those found in inflammatory arthritis. Thus, the correct option accurately reflects the typical presentation of reactive arthritis.