Hi.. Thanks for the query.. As per your complain swelling in Tonsils or Tonsillitis along with fever can be due to viral throat infection, however there can also be secondary bacterial infection along with viral.. Doing warm saline gargles can help, however, it will provide only temporary relief.. You should consult an ENT Physician and get evaluated and a thorough clinical evaluation and investigations like throat swab culture can be done.. If he is allergic to Amoxicillin he can be advised other groups of antibiotics like Azithromycin for reducing infection.. Along with it anti-inflammatory painkillers like Ibuprofen can also be advised.. Continue doing warm saline gargles and also do steam inhalation.. You can also give him soft and bland diet.. Sipping plenty of warm fluids can help.. Hope this information helps.. Regards..