Thanks for posting your query here.
Cough/
Cold are very common upto 6 years of age and most children get upto 3-5 episodes during these years. There are number of causes varying from
allergy to virus infection to bacterial infections, manifesting with cough/cold.
I would suggest to discuss with your doctor if he feels this is allergic in nature or not. There are anti-allergic medicines which can be used for couple of weeks to months, but the decision to commence them is to be by the treating doctor.
I can appreciate your concerns that the prescription is different each time you visit your doctor. That can be due to associated signs which he may have picked up during examination and also considering the response in relation to previous medications.
There are many ayurvedic medicines which are widely publicized, but I will be unable to comment on their efficacy.
Feel reassured that this is quite a common problem in children of this age group. Do discuss with your doctor and ask if the symptoms recur, any of the medicines can be started in emergency. However, self-medications is not recommended apart from emergency use.
Regards
Dr Tejas Shah
Pediatrician