Dr. Bakewell noted the entheseal features that can be used to support a diagnosis of PsA: hypoechogenicity, thickening, Doppler signal, bone erosions, enthesophytes/calcifications and bursal enlargement, although she noted that none of these signals are specific to PsA. These signals can also be used to evaluate potential disease flare or to evaluate a potential remission, in addition to other signals, such as those specifically defined for dactylitis.
Additionally, in diagnosing patients with psoriasis with early PsA, one should examine at a minimum the bilateral quadriceps tendon, patellar ligament, Achilles tendon and plantar fascia entheses. In assessing patients with psoriasis for potential PsA, ultrasound should include scans of the hand, wrist, foot and relevant symptomatic joints.
Use in Selection Populations & Collaborative Care
Negative treat-to-target clinical trials employing a strictly scheduled use of MSUS failed their primary end points, which may have dissuaded some in the rheumatology community of the benefit of this modality.2,3 However, Dr. Bakewell responded that this finding doesn’t demonstrate an overall lack of utility. She noted that MSUS is not required for every patient at every visit, and it should only be used if certain clinical questions need to be addressed. Moreover, it may benefit certain populations more than others.
Dr. Kaeley emphasized that MSUS can help distinguish RA-related inflammation from other non-RA inflammatory conditions, such as gout. This nuance may be especially helpful to clarify the source of pain in some difficult-to-treat patients.
MSUS may also be helpful guiding treatment in patients with other comorbidities, such as RA and fibromyalgia. Dr. Kaeley said, “Patients with RA and fibromyalgia tend to have more steroid exposure and a higher prevalence of biologic use [compared with those with RA only], because the composite disease scores tend to overestimate disease activity in these patients, especially when compared with ultrasound.”
MSUS may be helpful in patients who have a difficult physical exam (e.g., obese patients), and it may help reduce physician bias in evaluating elderly patients. Dr. Kaeley noted it can also be particularly beneficial if the patient and provider impressions of joint activity are non-concordant to help clarify the actual clinical status.
The same principles apply to PsA. Dr. Bakewell noted that it can be helpful both for reassuring a patient with comorbid noninflammatory pain, but also for educating patients whose MSUS may show more inflammation than indicated by their perceived pain.
The Voting Panel has currently reached consensus on 55 guidance statements in total, with an additional five statements going back for reconsideration in a second round of voting. This progress will be followed by manuscript creation and review by the ACR, USSONAR and the journal of publication. The release date for the future full document is not yet known.
