Please do a cbc with absolute  eosinophil count.If aec is on the higher side do a comprehensive allergy  test.

Please Allergies means lower body resistance Instead of doing tests, try to increase your immunity so that recurrence will be prevented Do following,,,.. Wake up early go for morning walk in greenery daily with relaxed mind Do yogasanas and pranayam daily Put some cow ghee drops in both nostrils regularly at night Take dates beet root jaggery green leafy vegetables regularly Take Echinacea Q Liquid Homeopathic medicine 10 drops in 50 ml water Twice a day for 3 to 6 mths These points will help you a lot, will prevent recurrence of colds and cough