Tonsillitis, the medical term for a tonsil infection, is an inflammation of the tonsils that causes swelling, sore throat, and pain when swallowing. The tonsils will appear red and swollen, and may contain white or yellow patches. Additional symptoms include chills and fever, headache, swollen lymph nodes, bad breath, change in the voice, and stiff neck. Children may display increased irritability and a refusal to eat, and may drool.
In their role as defenders of the immune system, the tonsils are exposed to a variety of germs on a daily basis. Viral and bacterial infections are the usual cause of tonsillitis, though allergies sometimes play a role, as well. One of the more common offenders is the streptococcus bacterium, associated with another condition called strep throat. After puberty, the tonsils begin to shrink in size, and their immune system role greatly diminishes.