Hi welcome to the health care magic Your child here can have acute bronchitis like upper respiratory tract infection and so much dyspnea and cough present Cough in fits also occur in whooping cough like infective condition I recommend you to consult pulmonologoist or pediatrician for following work up... _Auscultation first need to heard rhonchi or rales _chest x ray _sputum examination _throat swab if needed _CBC According to examination and reports further treatment given You have already tried decongestant drugs Hence here antibiotic course will be needed for your child case (as improvement not seen) Hope your concern solved