This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Skin lesions and disorders of pigmentation, Subject name: Dental
[{'content': 'Topical azelaic acid is used in - \nSelect and explain. \nA. Hyperpigmentary disorders, B. Dermatophvte infections, C. Vitiligo, D. Mixed infections', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Topical azelic acid is used in treatment of melasma a hyper pigmentation disorder. azeliac acid is a competitive tyrosinase inhibitor that inhibit the synthesis of melanin. It is used as 10-20% cream and is as efficacious as hydroquinone. IADVL textbook of dermatology , pigmentary disorders page 750', 'role': 'assistant'}]