This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Skin
[{'content': 'Silver plaques are a feature of: September 2006 \nSelect and explain. \nA. Lichen planus, B. Psoriasis, C. Vitiligo, D. Albinism', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B: Psoriasis Plaque psoriasis is the most common presentation of psoriasis and of all the patterns is the most likely to affect the typical areas of the elbows, knees, umbilicus and lower back. It tends to be a relatively persistent or chronic pattern of psoriasis that can be improved with treatment but is difficult to clear completely with topical treatments alone. It is characterised by large flat areas (plaques) of psoriasis with typical silvery scale. These plaques may join together to involve very extensive areas of the skin paicularly on the trunk and limbs. It is often accompanied by scalp and nail psoriasis.', 'role': 'assistant'}]