The weight and height figures you have mentioned are very high for a 5 1/2 year old child. Is he really 150 cm(5 feet) tall?
The recurrent cough and cold is an allergic problem like allergic rhinitis
, triggered by a viral infection of the upper respiratory tract
. There is no need to give him antibiotics repeatedly. Better consult a Pediatrician
who can examine and make a proper diagnosis. If your child has Asthma, he may benefit from inhalers. A flu shot every year may also help him. The problem is likely to subside as he grows older. Try giving him Vitamin C
chewable tabs daily or even Chavanprash which contains lot of this vitamin derived from Aamla.