Background/Purpose: Simultaneous control of joint symptoms and degree of skin involvement has been linked to improvement in health-related quality of life in patients with coexistent PsA and psoriasis (PsO). The objective of this analysis was to understand how the relationship between skin and joint severity is impacted by PsA therapy.

Methods: Enrollment visit data from Corrona PsA/SpA registry were obtained from 3/21/2013-9/30/2016. To be included in the analysis, patients had to have a diagnosis of PsA and history of PsO. Patients were subsequently stratified into three subgroups based on therapy at enrollment: a) not on DMARD therapy, b) on csDMARDS, or c) on anti-TNFs. Patient demographic and disease characteristics were compared.

The relationship of skin severity (BSA) and joint activity (CDAI) was evaluated using linear regression. To evaluate whether factors modified the relationship between CDAI and BSA, multiple linear regression was performed.

Results: 1,542 patients met inclusion criteria and 1484 had known therapy status. 266 (18%) patients were on no DMARD therapy, 430 (29%) were on csDMARDs only, and 765 (52%) were on anti-TNFs at time of enrollment. Patients on no DMARD therapy were more likely to be female, younger, have shorter PsA duration, more likely to have dactylitis, enthesitis and higher levels of joint activity, skin severity, and HAQ, and less likely to have MDA. (Table). Patients on TNFi therapy had better disease control (CDAI and BSA) than other therapy subgroups, but proportion of patients with MDA was similar to those on csDMARDS.

In the no DMARD therapy group, no variables tested resulted in a significant impact on the relationship. In both csDMARD and TNFi groups, age, BMI, SPARCC, HAQ, patient reported pain and fatigue significantly impacted the relationship between joint activity and skin severity. In csDMARDs group, dactylitis modified the relationship and in TNFi group, PsO onset and MDA modified the relationship.

Table: Descriptive statistics for patient characteristics, disease characteristics and PROs stratified by current drug therapy

Proportions are calculated among patients with non-missing response. Enthesiits SPARCC Score and Dactylitis Counts are among patients with enthesitis and dactylitis, respectively

Conclusion: There were significant differences in disease characteristics and patient reported outcomes in PsA patients with PsO history when stratified by type of therapy. The relationship between joint activity and skin severity is influenced by age, SPARCC, patient reported pain, fatigue, and HAQ among patients on DMARDs and TNFi therapies. Dactylitis and PsO onset also modified the relationship among csDMARD and TNFi therapy groups, respectively. For improved disease management of PsA patients with a history of PsO, consideration of these factors is important when determining type of therapy.