A 20 year old student presents with fever and myalgia. On examination, he had vesicular haemorrhagic lesions in his lips and oral cavity with inability to swallow. He also had redness of eyes with photophobia. He has no genital or anal lesions and no history of arthritis. Scrapings from the oral lesions were negative in Tzanck smear.
His blood routine, chest X-ray, liver function and all other investigations are normal. Blood cultures and swabs were also negative. He is an epileptic and his treatment was modified 10 days back to control recurring seizures. What is the most probable diagnosis? Source: International Journal of Critical Illness and Injury Science.