Let’s Discuss Part 2: More Insights from the ACR Convergence 2025 Review Course

A very instructive case that Dr. Shaw discussed involved a middle-aged woman who presented with erythematous annular and indurated plaques on her face, trunk and extremities and had false-positive syphilis test results during two pregnancies much earlier in life. Testing at the time of presentation showed a high-titer positive rapid plasma reagin (RPR). Although the Poll Everywhere results indicated that the audience thought the positive RPR was a false positive due to anticardiolipin antibodies, Dr. Shaw explained that secondary syphilis was the correct diagnosis as a false positive RPR should be low titer when occurring in the setting of antiphospholipid antibodies. After demonstrating a positive fluorescent treponemal antibody absorption (FTA-ABS) test and with a skin biopsy showing numerous spirochetes, the patient was treated with one dose of intramuscular penicillin G and the patient’s rash was nearly resolved.

Gout

Dr. Gaffo

The next speaker, Angelo Gaffo, MD, MSPH, section chief of rheumatology at the Birmingham VA Medical Center and associate professor of medicine in the Division of Rheumatology at the University of Alabama at Birmingham, lectured on gout, a condition that affects about 5% of the U.S. population.² Although rheumatologists often think of this crystalline arthritis affecting joints, Dr. Gaffo noted that the dorsum of the feet and hands and even the sacroiliac joints can be involved as well. Similarly, although the intercritical periods of gout are typically asymptomatic for patients, individuals with advanced gout may experience pain and stiffness even between true gout flares.

Dr. Gaffo implored clinicians not to be fooled by a seemingly normal or low serum uric acid level during an acute flare, when the active inflammatory process can cause a uricosuric effect and result in this misleadingly low urate level. Although radiographs continue to be helpful in diagnosis, especially if the classic rat bite erosions or tophi are visualized, other imaging modalities are of great help as well. Ultrasound of a joint that has been affected by gout can reveal the double contour sign, an echogenic line on the outer surface of the joint cartilage running parallel to the subchondral bone; this occurs secondary to deposition of monosodium urate (MSU) crystals on the surface of hyaline articular cartilage. Dr. Gaffo is a proponent of dual-energy computed tomography (DECT) scans in cases where a crystal-proven diagnosis has not been obtained and where diagnostic uncertainty exists. DECT scans are fast, do not require contrast and can detect MSU deposition even in intercritical periods of the disease, although Dr. Gaffo warned that DECT scans may be less helpful early in the disease course when less MSU deposition has occurred.