This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Psoriasis, Subject name: Dental
[{'content': 'Ahritis mutilans is a feature of? \nSelect and explain. \nA. Lichen planus, B. Psoriasis, C. Staphylococcal scalded skin syndrome, D. Eczema', 'role': 'user'}, {'content': 'Answer: B \nExplanation: PSORIATIC AHRITIS Classical (DIP type) most commonly involving the distal interphalangeal joints and less commonly the knees, hips, ankles, and wrists; Asymmetric oligo-aicular type (MC type) Symmetrical polyaicular type Disease limited to the spine (psoriatic spondylitis). Ahritis mutilans(X-Ray shows pencil in cup sign, pestle in moar sign)', 'role': 'assistant'}]