My 4 year old keeps coughing after eating food It?

Patient: My 4 year old keeps coughing after eating food. It normally only happens in the morning and after an evening meal.He is asthmatic, but he is currently taking inhalers and has just finished a 5 day course of steriods.He is well in himself, no colds, no flu like symptoms. Just this very bizarre cough. He also is still complains of a tight chest. He describes his throat as feeling sore/scratchy/tight after eating.He is allergic to certain foods and had a dairy allergy up until he was 2. I have saw several doctors who think it’s just a viral thing, but no one really knows! Any advice or help would be great as I want to give him the proper medication of he needs it. I’m at my wits end with worry and petrified to send him to school.Please help!