looking for expert advice. my daughter 4.8 years old. She is having dry cough. her throat looks little red. n she coughs whenever she lays down, afternoon nap or at night. sometimes coughing increases at night or midnight or in the morning.. she doesn't have nasel congestion nor fever. she is very active, playful and has proper weight gain. also taking proper diet too. what could be the reason of Dry cough??