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
In psoriasis, the following are seen except: 
Select and explain. 
A. Nail changes, B. Ahritis, C. CNS involvement, D. Skin involvement
C: CNS involvement
Answer: C: CNS involvement 
Explanation: Psoriasis is characterized by red, scaly, sharply demarcated indurated plaques present paicularly over extensor surfaces and scalp. Nail involvement is seen with all types of psoriasis and is frequently present with psoriatic ahropathy. An inflammatory ahritis is associated with psoriasis of skin and/or nails with a negative serological test. CNS involvement is not seen with psoriasis.