Which psoriatic arthritis subtype is characterized by severe destructive joint disease with telescoping of digits?

• A. DIP arthritis
• B. Spondylitis
• C. Arthritis mutilans
• D. RA-like polyarthritis

Answer: (C)

The main idea here is recognizing the psoriatic arthritis pattern that shows the most severe, destructive joint damage with a characteristic telescoping of the fingers. This finding points to arthritis mutilans, the most destructive form of psoriatic arthritis, where extensive bone resorption around the joints and soft tissue changes cause the digits to collapse and shorten in a telescoping appearance. Other patterns don’t produce this dramatic digit shortening: DIP-dominant arthritis mainly involves the distal interphalangeal joints and nails without such severe digit destruction; spondylitis primarily affects the spine and axial regions rather than the fingers; and an RA-like polyarthritis mimics rheumatoid arthritis in multiple joints but does not typically present with the telescoping of digits seen in arthritis mutilans.