Differences between early vs. late-onset of psoriatic arthritis: Data from the RESPONDIA and REGISPONSER registries

The objective was to evaluate the association between the age at onset of psoriatic arthritis (PsA) symptoms with the characteristics and burden of the disease.

This was an observational and cross-sectional study that included a subgroup of 231 patients with PsA with < 10 years of disease duration from the REGISPONSER and RESPONDIA registries. Patients were divided into two groups according to the age of PsA symptom onset (early onset: ≤ 40-years-old and late onset: ≥ 60-years-old). The characteristics and burden of the disease were compared between the two groups, and multivariate logistic regression was performed to determine the factors independently associated with late-onset PsA.

Patients from the early-onset group showed a significantly lower prevalence of males [94 (62.3%) vs. 38 (86.4%)] and a higher prevalence of enthesitis [44 (24.6%) vs. 5 (9.8%)] and sacroiliitis [30 (16.8%) vs. 4 (7.7%)]. Additionally, the early-onset group showed lower scores on the BASFI [2.2 (2.2) vs. 3.3 (2.5)] and minor structural damage (BASRI) in both the spine [1.6 (2) vs. 2.9 (3)] and whole axial skeleton (total BASRI) [1.9 (2.4) vs. 3.4 (3.4)]. In contrast, no statistically significant differences were found between the groups in disease activity evaluated by the BASDAI and ASDAS. Logistic regression analysis showed that late-onset PsA was independently associated with being male (OR 4.4, 95% CI: 1.3, 16.3), greater structural damage (total BASRI) (OR 3.3, 95% CI: 1.3, 8.1), a higher frequency of arthritis in the upper limbs (OR 2.8, 95% CI: 1, 7.7), and greater loss of function (BASFI) (OR 1.3, 95% CI: 1, 1.6).

Patients with late-onset PsA showed different clinical characteristics and greater disease severity than those with early-onset PsA.