EXcess use of antibiotics  will make the antibiotics immune. It results in leading to the damaging the immune system of anybody. Both adults and children are affected equally. Additionally whenever kids take antibiotics they run the risk of side-effects, such as stomach upset and diarrhea or even an allergic reaction.

According to recent study repeatedly use of antibiotics by kids may effect their development.

 http://navbharattimes.indiatimes.com/world/science-news/giving-kids-antibiotics-may-alter-their-development/articleshow/47891707.cms

I agree and have always been careful while administering any medication especially antibiotics to my own children. Other than cases where it is absolutely essential it should be avoided and in my experience , children become tougher and their immune system stronger when they combat normal diseases like flu, cold and cough etc..

Constant usage of antibiotics will make them immune. After some time immunity in the antibiotics damages the user's built in immune system both in children and adults equally. Children are more affected because their immune system of child much more sensitive. And this leads to all kinds of ailments.

There was a Doctor in our city , some years back who would refuse to prescribe antibiotics to small children. But there was always pressure from parents to do so. I have  seen him trying to convince parents that no harm will come to children, but very few parents would get convinced. Most of the parents would go to another doctor who gladly prescribed antibiotics. It is difficult these days not to tale antibiotics even by children.

Many parents are like that. They believe in pills and medicines stored in colorful bottles. Antibiotics after prolonged use become immune and stop functioning. This in turn damages the built in immune system in the children. Parents are not aware of this.