Tonsillitis and strep throat have similar symptoms because strep throat is considered a type of tonsillitis. Symptoms of tonsillitis include sore throat, redness and swelling in the tonsils, large, tender Lymph nodes in the neck, fever and difficulty or pain when swallowing, fever, stiff, upset stomach, headache and white or yellow discoloration on or around your tonsils.
Symptoms of strep include sore throat, small red spots on the roof of your mouth, difficulty or pain when swallowing, body aches, headache, nausea or vomiting, especially in children, swollen, and red tonsils with white streaks of pus.
Causes of tonsillitis can be caused by a variety of viruses such as influenza, coronavirus, adenovirus, HIV, herpes simplex virus and Epstein- Barr virus. In extreme cases they lead to scarlet fever, kidney inflammation and rheumatic fever.