Arthritis mutilans is due to:

Ans: a (Psoriatic arthritis) Ref: Harrison's, 16th ed,p. 1998; 17th ed, p. 2115Arthritis mutilans is due to psoriatic arthritis. Psoriatic arthritis involves PIP, DIP and metacarpopha- langeal joints and may or may not involve the wrist.Psoriatic arthritis can present with a wide spectrum of clinical features namely:1) Asymmetrical inflammatory oligoarthritis - 40%2) Symmetrical polyarthritis - 25%3) Predominant distal interphalangeal joint arthritis -15%4) Psoriatic spondylitis-15% C5) Arthritis mutilans - 5%.It is the most serious condition and the skin of fingers appears telescoped.NoteOsteoarthritis -Involves PIP, DIP and 1st carpometacarpal joint (base of thumb). Spares MCPand wrist.Rheumatoid arthritis -Involves any small joint of hand eg PIP, MCP, wrist. Sparing of DIP.Psoriatic arthritis -Involvement of PIP, DIP, MCP and wrist. Sparing of any joint may or may not be present.RememberIf DIP is involved, Rheumatoid arthritis can be ruled out.Similarly if MCP joint is involved, osteoarthritis can be ruled out.