To describe the design and methodology of APACHE, a cohort of patients with early peripheral psoriatic arthritis (pPsA), and to assess the main baseline clinical characteristics of the first included patients. APACHE is an ongoing prospective multicentre national cohort (NCT03768271) with a planned follow-up of 10 years. Included patients have recent-onset (<12 months) peripheral arthritis, a personal and/or family history of psoriasis, pPsA diagnosed by a rheumatologist, and no history of targeted disease-modifying antirheumatic drug therapy. At inclusion, demographic data, disease activity, comorbidities, and imaging results (not reported here) are collected. A descriptive analysis of these data was performed. The 186 study patients had a mean age of 44±11 years and mean arthritis duration of 6±4 months; 84 (45%) were women; 169 (91%) had a history of psoriasis (mean duration, 14 years) and 71 (38%) were receiving methotrexate. Disease activity was moderate with a mean DAPSA score of 19±14 and mean swollen and tender joint counts of 2.1±3.2 and 6.0±8.0, respectively. The initially involved joints were mainly the hands (40%) and knees (28%). Entheseal pain (39%) was more prevalent than dactylitis (27%). Comorbidities were common, with obesity in 27% and at least one cardiovascular risk factor or disease in 49% of patients. Patients with early peripheral PsA had moderate disease activity, a predominant oligoarticular profile, and a high prevalence of entheseal pain.
