There is limited evidence to support the benefits of routine screening for potential subclinical axial inflammation in patients with psoriasis, according to a study published in Arthritis Care and Research.
Study researchers examined potential subclinical involvement of the sacroiliac joints (SIJ) and other peripheral axial or peripheral components of the skeleton in 20 patients without prior clinical evidence of inflammation and compared them with 22 healthy controls. Both groups underwent dermatological and rheumatological examinations.
In addition, both patients and controls underwent 1.5 T MRI of the SIJ and entire spine. Scans for the study were then read by a blinded rheumatologist and radiologist. Analysis was done through a global assessment that took into consideration the presence or absence of SIJ inflammation and through lesion-based scores for predefined sacroiliac and spinal MRI features.
Males compromised 55% of patients and 45.5% of controls, and median duration of skin psoriasis was 23.0 years (interquartile ranges: 10.0-34.3 years). Results from the global assessment of MRI scans demonstrated that 5 (25.0%) patients with psoriasis and 2 (9.1%) controls were concordantly classified by both readers as having SIJ inflammation (P =.23).
Prevalence of sacroiliac MRI changes was similar in patients and healthy controls for all lesion types (P >.1). The patient group had a median of affected SIJ quadrants of 0.5 for bone marrow edema (BME) and fat metaplasia (FM), respectively, and 0.0 for erosion (ER). For the control group, medians were 0.8 for BME and 0.0 for FM and ER, respectively. No SIJ ankylosis was recorded in either group.
Spinal lesions had a similar prevalence in patients and controls, with medians of 1.0 and 0.5 vertebral corner inflammatory lesions (CIL), and 0.3 and 0.0 corner fat lesions (CFL), respectively. Regarding lesion frequency, there was no statistically significant difference between patients and controls (all P >.2). The frequencies for edematous and structural axial lesions did not differ significantly between patients and controls, both on SIJ and spine MRI.
Study limitations include a small study sample, a lack of HLA-B27–positive participants, and no follow-up data from participants. Researchers for the study concluded that data does not support recommending screening for subclinical axial inflammation by MRI in patients who have psoriasis activity clinically limited to the skin.
Bratu VA, Häusermann P, Walker UA, et al. Do patients with skin psoriasis show subclinical axial inflammation on MRI of the sacroiliac joints and entire spine? [published Online September 22, 2018]. Arthritis Care Res. doi: 10.1002/acr.23767