Table 2.

Clinical and imaging characterisation of patients with PsO prior to PsA onset

	Positive association with PsA development	No association with PsA development
Pain	4 studies (PsO=667; incident PsA=99)	0
Joint tenderness	3 studies (PsO=257; incident PsA=42)	0
Arthralgia	4 studies (1 study only in female)* (PsO=667; incident PsA=99)	1 study (in male)* (PsO=410; incident PsA=57)
Subclinical enthesopathy (US in 2 studies, pQCT)	3 studies (PsO=325; incident PsA=39)	0
Subclinical synovitis (US or MRI)	1 study (PsO=109; incident PsA=9)	2 studies (PsO=143; incident PsA=18)
Subclinical tenosynovitis (US or MRI)	0	2 studies (PsO=143; incident PsA=18)

*The definition of arthralgia used in these studies were different: in Faustini et al, this was the presence of at least one tender joints; in Zabotti et al, it was recent onset of non-inflammatory joint and/or entheseal pai and in Simon et al in terms of VAS and tender joints.

pQCT, peripheral quantitative tomography; PsA, psoriatic arthritis; PsO, psoriasis; US, ultrasonography.