Hello Thanks for the query There can so many causes of persistent or recurrent cough. One of them is chronic pharyngitis or bronchitis. As on clinical examination your E.N.T. doc has made the diagnosis of pharyngitis there is no role of deriphyllin. Antibiotic, antiallergic, steam inhalation and warm saline gargle is the main modality of treatment in this case. Follow the advice of your doc and even then if cough persists then proper laboratory and radiological investigation may be needed to find out the cause( long duration cough with fever may be due to tuberculosis, even in absence of respiratory distress). I hope this answers your query well Wish you and your family good health With regards