The most common cause is viral infection and includes adenovirus, rhinovirus, influenza, coronavirus, and respiratory syncytial virus. It can also be caused by Epstein-Barr virus, herpes simplex virus, cytomegalovirus, or HIV. The second most common cause is bacterial infection of which the predominant is Group A β-hemolytic streptococcus (GABHS), which causes strep throat. Less common bacterial causes include: Staphylococcus aureus (including methicillin resistant Staphylococcus aureus or MRSA), Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydia pneumoniae, Bordetella pertussis, Fusobacterium sp., Corynebacterium diphtheriae, Treponema pallidum, and Neisseria gonorrhoeae.
Anaerobic bacteria have been implicated in tonsillitis and a possible role in the acute inflammatory process is supported by several clinical and scientific observations.
Under normal circumstances, as viruses and bacteria enter the body through the nose and mouth, they are filtered in the tonsils. Within the tonsils, white blood cells of the immune system destroy the viruses or bacteria by producing inflammatory cytokines like phospholipase A2, which also lead to fever. The infection may also be present in the throat and surrounding areas, causing inflammation of the pharynx.
Sometimes, tonsillitis is caused by an infection of spirochaeta and treponema, in this case called Vincent's angina or Plaut-Vincent angina.
The diagnosis of group A beta-hemolytic streptococcus (GABHS) tonsillitis can be confirmed by culture of samples obtained by swabbing both tonsillar surfaces and the posterior pharyngeal wall and plating them on sheep blood agar medium. The isolation rate can be increased by incubating the cultures under anaerobic conditions and using selective growth media. A single throat culture has a sensitivity of 90–95% for the detection of GABHS (which means that GABHS is actually present 5–10% of the time culture suggests that it is absent). This small percentage of false-negative results are part of the characteristics of the tests used but are also possible if the patient has received antibiotics prior to testing. Identification requires 24 to 48 hours by culture but rapid screening tests (10–60 minutes), which have a sensitivity of 85–90%, are available. Older antigen tests detect the surface Lancefield group A carbohydrate. Newer tests identify GABHS serotypes using nucleic acid (DNA) probes or polymerase chain reaction. Bacterial culture may need to be performed in cases of a negative rapid streptococcal test.
True infection with GABHS, rather than colonization, is defined arbitrarily as the presence of >10 colonies of GABHS per blood agar plate. However, this method is difficult to implement because of the overlap between carriers and infected patients. An increase in antistreptolysin O (ASO) streptococcal antibody titer 3–6 weeks following the acute infection can provide retrospective evidence of GABHS infection and is considered definitive proof of GABHS infection.
Increased values of secreted phospholipase A2 and altered fatty acid metabolism in patients with tonsillitis may have diagnostic utility.
Common signs and symptoms include:
- sore throat
- red, swollen tonsils
- pain when swallowing
- high temperature (fever)
- headache
- tiredness
- chills
- a general sense of feeling unwell (malaise)
- white pus-filled spots on the tonsils
- swollen lymph nodes (glands) in the neck
- pain in the ears or neck
- weight loss
- difficulty ingesting and swallowing meal/liquid intake
- difficulty sleepin.
Less common symptoms include:
- nausea
- fatigue
- stomach ache
- vomiting
- furry tongue
- bad breath (halitosis)
- voice changes
- difficulty opening the mouth (trismus)
- loss of appetite
- anxiety/fear of chokin.
In cases of acute tonsillitis, the surface of the tonsil may be bright red and with visible white areas or streaks of pus.
Tonsilloliths occur in up to 10% of the population frequently due to episodes of tonsillitis.