Researchers Mustafa Khan and colleagues sought to determine the contribution of radiological (x-ray) findings at the initial doctor's visit with respect to classifying patients with psoriatic arthritis (PsA), and to determine the extent to which clinical disease patterns change over time. Results of the study were published in a recent issue of The Journal of Rheumatology.

Patients with PsA were followed at 6-12 month intervals since 1978. Overall, 86 patients took part, all of whom were enrolled in the study within one year of diagnosis and followed for at least one year thereafter.

To assign a clinical PsA pattern, the researchers gathered clinical information, like the actively inflamed joint count, damaged joint count, and the presence of back disease and arthritis. A separate radiology pattern based on x-rays alone and a combined clinical and radiological pattern was also assigned at each visit with the patients. Researchers compared the patterns to each other over the years.

In 23% of the patients, the radiological assessment in the initial visit showed evidence of patterns not detected clinically. 49% and 77% of the patients showed clinical pattern change within one and five years, respectively. A comparison between the group that changed pattern and the one that did not change pattern in five years did not reveal any significant features.

The researchers conclude that radiological assessments add information not gained from clinical assessment alone. In addition, clinical patterns do change over time in the majority of patients. Both elements must be taken into consideration when developing classification criteria for PsA.