Dactylitis — SCE Rheumatology MCQ

Instant feedback + full explanation. One question, done properly.

EasySpondyloarthropathiesDactylitisSCE Rheumatology

A 41-year-old man has diffuse swelling of the entire right fourth toe and pain at several DIP joints. He has nail pitting and a scaly rash behind the ears. RF is negative and CRP is mildly raised. Foot radiograph shows early periostitis. What is the most likely diagnosis?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: B — Psoriatic arthritis

Explanation lettering: D = shown as A · A = shown as B · E = shown as D · B = shown as E

Psoriatic arthritis is best because whole-digit swelling with nail disease, psoriasis and periostitis is psoriatic dactylitis. B is less suitable because gout causes acute crystal synovitis rather than chronic whole-digit dactylitis with nail psoriasis; C is less suitable because RA typically spares DIP joints and lacks periostitis; D is less suitable because cellulitis may mimic swelling but would not explain nail disease and periostitis; E is less suitable because osteoarthritis causes bony enlargement rather than inflammatory sausage digit. Clinical pearl: dactylitis includes synovitis, tenosynovitis and soft-tissue inflammation.

Reference: NICE NG65; BSR psoriatic arthritis biologic guideline 2022