Two patients had completely normal nails in the target finger at 6 months, with no difference in nail clearance between nail matrix features and nail-bed abnormalities.Table 1 Clinical assessments Baseline 6 months PASI Median (range) 2.9 (0.2–7.3) 0.2 (0–1.8) Swollen joint count Mean (SD) 11 (6) 1 (1) Tender joint count Mean (SD) 12 (7) 1 (1) SPARCC Enthesitis Index Mean (SD) 3.4 (2) 0.4 (1) mNAPSI Mean (SD) 28 (15) 9 (6) mNAPSI in the target finger Median (range) 3 (3–5) 1 (0–2) Visual analogue score for nail pain Median (range) 12 (0–60) 0 (0–2) PASI, Psoriasis Area and Severity Index; SPARCC, Spondyloarthritis Research Consortium of Canada Enthesitis Index; mNAPSI, modified Nail Psoriasis Severity Index. Three patients with purely nail-bed nail disease at baseline also had marked underlying BMO, synovitis and enthesitis on MRI.Table 2 MRI scores for each patient Patient BMO score (0–3) Synovitis score (0–2) Comments Baseline Follow-up Baseline Follow-up A 0 0 1 0 No enthesitis B 2 2 2 2 Marked changes but overall improvement C 3 3 1 2 Effusion resolved at follow-up D 2 1 2 0 Flexor tendon changes resolved E 0 0 1 1 Persistent enthesopathy collateral ligaments and extensor tendon F 2 2 2 2 Overall improvement on follow-up scan despite persistent BMO G 1 1 2 1 Marked improvement in collateral ligaments BMO, bone marrow oedema. ...our study demonstrated persistent subclinical musculoskeletal inflammation on MRI despite a good clinical response.