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': 'True about Pityriasis rubra pilaris? \nSelect and explain. \nA. Isolated patches of normal skin found, B. Occurs mainly in adults, C. Common in females, D. Oral cyclosporine is drug of choice', 'role': 'user'}, {'content': "Answer: A \nExplanation: Pityriasis rubra pilaris Definition: Heterogeneous group of disorders that have circumscribed follicular keratoses, branny scale and an orange-red erythema. C/F: It shows an equal sex incidence. Bimodal age distribution with peaks in the first and fifth decades. Lesion: Erythematous follicular hyperkeratosis giving a 'nutmeg grater' appearancee. Mainly seen over the elbows, knees, wrists and back of fingers. Pt. presents with well defined salmon red or orange-red dry scaly plaques. Islands of normal skin are present, the so called 'islands of sparing'. Associated disorders: Leukaemia Metastatic carcinoma Treatment: Topical : Coicosteroids + Salicylic acid (if thickening). In the erythrodermic phase: Acitretin or Isotretinoin are used.", 'role': 'assistant'}]