Dear Sir/ Madam, Thank you for posting you query at healthcaremagic.com. Tonsils act as a fist line of defense mechanism for controlling further infection of respiratory tract. They also produce antibodies to fight against infection. But sometimes the tonsils themselves become infected by bacteria or viruses, where they swell and become inflamed, which is called as tonsillitis. This age group is prone for repeated tonsillitis. Left alone, it may cause further complication like rheumatic fever, rheumatic chorea, and arthritis. I strongly recommend to give full dose of antibiotics to your 5 year old kid as part of management. The drugs which he is already taking is the first drug of choice. This can be continued. Hope by this explanation you have got why antibiotics are important in tonsillitis. Wishing your kid a speedy recovery. With best wishes, Dr. Vishwanath Patil