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: Pharmacology
[{'content': "Psoralan 'A' is used in the treatment of ? \nSelect and explain. \nA. Pemphigus, B. Vitiligo, C. Pityasis alba, D. Ichtyosis", 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Vitiligo o Psoralen and UV-A have synergistic action, therefore they are used in combination as PUVA therapy. o PUVA is used in 1. Psoriasis (most impoant and most common use) 3. Vitiligo 2. Eczema 4. Cutaneous T-cell lymphoma", 'role': 'assistant'}]