Table 1: Basic demographic and clinical characteristics of psoriatic arthritis (PsA) and psoriasis (PsO) groups.

VariablePsA group
( )
PsO group
( )

Male : female ratio24 : 2231 : 11
Age (mean ± SD; years)54.35 ± 11.8745.60 ± 15.72
BMI (mean ± SD; kg/m2)29.38 ± 6.4128.86 ± 9.80
Current smokers (%)2012
Age at diagnosis of PsO (mean ± SD; years)38.91 ± 14.4728.84 ± 15.82
Age at diagnosis of PsA (mean ± SD; years)45.26 ± 13.80
Disease course severity (mild : moderate to severe)0 : 466 : 36
Psoriasis guttata (%)420
Arthritis mutilans (%)2
Axial arthritis (%)17
Distal arthritis (%)4
Asymmetrical oligoarthritis (%)54
Symmetrical polyarthritis (%)43
Therapy
 Received MTX therapy (%)8557
 Received systemic steroid
 treatment (%)
132
 Received 311 nm NB-UVB
 therapy (%)
738
 Received PUVA therapy (%)231
 Received biological therapy (%)1352

PsO: psoriasis vulgaris, PsA: psoriatic arthritis, BMI: body mass index, MTX: methotrexate, PUVA: psoralen + ultraviolet A, 311 nm NB-UVB: 311-nanometer narrow-band ultraviolet B. Symmetrical arthritis: bilateral arthritis with a frequency of >50%.
Patients previously or currently treated with DMARDs, systemic therapy or full-body phototherapy were regarded as “moderate-to-severe” patients, whereas the others were considered to exhibit a “mild” disease course.