This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Rheumatoid Arthritis, Subject name: Orthopaedics
Distal interphalangeal joints are involved in all except - 
Select and explain. 
A. Psoriatic arthritis, B. Rheumatoid arthritis, C. Reactive arthritis, D. Osteoarthritis
B: Rheumatoid arthritis
Answer: B: Rheumatoid arthritis 
Explanation: Ans. is 'b' i.e., Rheumatoid arthritis JointImportant arthritis involving the jointDistal interphalangeal jointProximal interphalangeal jointMetacarpophalangeal joint1st Carpometacarpal jointWristOsteoarthritis, Psoriatic arthritis, Reactive arthritisOsteoarthritis, RA, SLE, Psoriatic arthritisRA. pseudogout, hemochromatosisOsteoarthritisRA, Pseudogout, gonococcal arthritis, juvenile arthritisSpared jointo Wrist and MTPo DIPOsteoarthritisRA