Characteristics and outcomes | Non-dactylitic PsA (96/177 (54.2%)) | Dactylitic PsA (81/177 (45.8%)) | Difference/p value |
Clinical | |||
Age (years), mean (SD) | 44.4 (12.8) | 43.7 (13.3) | 0.7 (−3.2 to 4.5) |
Male | 38 (39.6%) | 42 (51.9%) | p=0.10 |
Symptom duration (months), median (IQR) | 18.0 (10.5–36.0) | 12.0 (6.0–24.0) | −6.0 (−13.1 to 1.1) |
Duration from diagnosis (months), median (IQR) | 1.1 (0–2.7) | 1.2 (0.3–4.6) | 0.03 (−0.9 to 1.0) |
Symptoms <24 months, patients (%) | 64/96 (66.7) | 68/81 (84.0) | p=0.008 |
Early morning stiffness (min), median (IQR) | 50.0 (15.0–90.0) | 60.0 (15.0–180.0) | 0 (−24.1 to 24.1) |
TJC (78), median (IQR) | 4.0 (1.0–10) | 9.0 (5.0–19.0) | 5.0 (2.0 to 8.0)** |
SJC (76), median (IQR) | 1.0 (0.0–3.0) | 7.0 (4.0–13.0) | 6.0 (4.3 to 7.6)*** |
TJC (78) median (IQR) (excluding dactylitis) | 4.0 (1.0–10.0) | 5.0 (2.0–11.0) | 1.0 (−1.4 to 3.4) |
SJC (76) median (IQR) (excluding dactylitis) | 1.0 (0.0–3.0) | 3.0 (1.0–6.0) | 2.0 (0.8 to 3.3)** |
Current psoriasis | 96/96 (100.0%) | 74/81 (91.4%) | p=0.003** |
Family history of psoriasis | 52/94 (55.3%) | 49/78 (62.8%) | p=0.32 |
PASI, median (IQR) | 2.9 (0.8–4.9) | 1.9 (0.4–4.2) | −1.2 (−2.4 to 0.0) |
Psoriatic nail dystrophy | 49/96 (51.0%) | 44/81 (54.3%) | p=0.66 |
mNAPSI, median (IQR) | 2.0 (0.0–7.5) | 0.0 (0.0–8.0) | −2.0 (−3.7 to −27.9)* |
Clinical Enthesitis | 34/96 (35.4%) | 42/81 (51.9%) | p=0.027* |
MASES score, median (IQR) | 0.0 (0.0–2.0) | 1.0 (0.0–2.0) | 1.0 (0.4 to 1.6)** |
BMI, median (IQR) | 28.2 (24.0–32.1) | 28.6 (25.0–31.5) | 0.3 (−1.7 to 2.4) |
Smoking (current) | 19 (19.8%) | 9 (11.1%) | p=0.11 |
Disease phenotype | |||
Oligoarthritis (defined by SJC <5) | 83/96 (86.5%) | 28/81 (34.6%) | p<0.001*** |
Oligoarthritis (defined by TJC and/or SJC <5) | 48/96 (50%) | 29/81 (35.8%) | p=0.058 |
DIP joint disease | 7/93 (7.5%) | 13/77 (16.9%) | p=0.058 |
Axial disease | 17/94 (18.1%) | 9/78 (11.5%) | p=0.23 |
Arthritis mutilans | 0 | 0 | 0 |
Laboratory markers | |||
CRP (mg/L), median (IQR) | 5.0 (5.0–9.3) | 8.1 (5.0–18.4) | 3.1 (0.9–5.3)** |
Elevated CRP (>10 mg/L) | 24/96 (25.0%) | 36/81 (44.4%) | p=0.006** |
ESR, median (IQR) | 11.0 (5.0–25.0) | 16.5 (7.0–27.0) | 7.0 (0.4–13.6)* |
Composite outcomes | |||
DAPSA score, median (IQR) | 20.8 (12.6, 30.5) | 24.4 (14.9, 36.5) | p=0.07 |
Patient-reported outcomes (PROs) | |||
PsAQoL, median (IQR) | 6.0 (0.0–13.0) | 6.0 (2.0–12.0) | 0.0 (−4.1 to 4.1) |
DLQI, median (IQR) | 3.0 (1.0–9.0) | 2.0 (1.0–6.0) | −1.0 (−3.3 to 1.3) |
HAQ, median (IQR) | 0.75 (0.25–1.50) | 0.75 (0.38–1.38) | 0.125 (−0.23 to 0.48) |
*p<0.05, **p<0.01, ***p<0.001.
BMI, body mass index; CRP, C reactive protein; DAPSA, Disease Activity in Psoriatic Arthritis; DIP, distal interphalangeal; DLQI, Dermatology Quality of Life Index; ESR, erythrocyte sedimentation rate; HAQ, Health Assessment Questionnaire Disability Index; MASES, Maastricht Ankylosing Spondylitis Enthesitis Score; mNAPSI, Modified Nail Psoriasis Severity Index; PASI, Psoriasis Area Severity Index; ; PsA, psoriatic arthritis; PsAQoL, PsA quality of life; SJC, swollen joinr count; TJC, tender joint count.