Family Nurse Practitioner Exam

Which physical exam finding is most specific for systemic lupus erythematosus (SLE)?

1. Swollen and painful joint involvement

2. Fatigue and myalgia

3. Stiffness and swelling of multiple joints

4. Malar rash

The correct answer is: Malar rash

The malar rash is the most specific physical exam finding associated with systemic lupus erythematosus (SLE). This distinctive rash, often described as a "butterfly rash," typically appears over the cheeks and bridge of the nose and is a hallmark of the disease. Its presence is tied closely to the immunopathology of lupus, where skin manifestations arise due to photosensitivity and immune dysregulation. While swollen and painful joint involvement, fatigue and myalgia, and stiffness with swelling of multiple joints can be present in a variety of rheumatologic conditions, they are not exclusive to SLE. Such symptoms can also be observed in other conditions, making them less specific for lupus. Therefore, the malar rash stands out as a defining feature that clinicians look for when diagnosing SLE, making it the most reliable physical exam finding in this context.