An overview of how ultrasound can guide treatment for patients with rheumatoid and psoriatic arthritis.

INTRODUCTION: The treatment of rheumatic diseases has dramatically changed thanks to the availability of novel drugs. Besides clinimetric indexes, there is a strong need for valid, rapid, and sensitive-to-change, possibly noninvasive, and low-cost instruments to accurately assess treatment outcomes and to select the target patient.Musculoskeletal ultrasound (MSUS) has recently been shown to be able to respond to such needs. Indeed, it seems instrumental as a disease outcome measurement as it is capable to capture both the inflammatory state and the structural damage, allowing clinicians to accurately assess a patient's condition and make informed treatment choices.

AREAS COVERED: In this narrative review, the authors summarize the up-to-date knowledge on how MSUS can guide treatment for patients, with rheumatic diseases focusing on rheumatoid arthritis (RA) and psoriatic arthritis (PsA), particularly helping clinicians in monitoring disease activity and in identifying responses to currently approved biological and targeted synthetic disease modifying anti-rheumatic drugs (bDMARDs and tsDMARDs).

EXPERT OPINION: So far, knowledge of the evolving pattern of MSUS is paramount to avoid misinterpretations. However, usage of US standardized clinimetric indexes as well as the choice of the target joints are still missing points in the daily clinical workflow and the decision-making process.