This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lichen planus and Other papulosquamous disorders, Subject name: Dental
[{'content': 'Which of the following is known to be severely pruritic? \nSelect and explain. \nA. Lichen planus, B. Psoriasis, C. Icthyosis, D. Secondary syphilis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Purple polygonal papules marked by severe pruritus; lacy white markings, especially associated with mucous membrane lesions is feature of lichen planus. Psoriasis is variably pruritic. Icthyosis: characterised by severe dryness, fish like scales. There are 5 P in Lichen Planus:Plain, Purple, Polygonal, Pruritic, Papule/ Plague', 'role': 'assistant'}]