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 A 7-year-old boy comes in complaining of a sore throat and generally feeling sorry for himself.  He has pus all over his tonsils.

Should you treat him with antibiotics?

Bottom Line

Tonsillitis is usually viral

Treatment is mainly symptomatic (fluids, pain relief)

The main reason for antibiotics is in strep pyogenes to prevent the complication of rheumatic heart disease

The antibiotic benefit is only significant in high risk groups

Isn’t tonsillitis mostly viral?

Tonsillitis/pharyngitis can be either bacterial or viral. It can be difficult to distinguish between the two.

Pus on the tonsils does not mean it’s bacterial!

The most commons viruses causing tonsillitis/pharyngitis are rhinovirus; coronavirus; adenovirus; herpes simplex; parainfluenza; echovirus; coxsackie A; Epstein-Barr; CMV.


What are the likely symptoms?

Symptoms of tonsillitis/pharyngitis include sore throat; fever; odynophagia; hoarse voice; vomiting; cough; diarrhoea; arthralgia; tonsillo-pharyngeal erythema; tonsillo-pharygneal exudate; soft palate petechiae; cervical lymphadenitis; rash; conjunctivitis; anterior stomatitis; discreet ulcers.

What are the different types of tonsillitis?

Epstein-Barr Virus (EBV)

In EBV the patient presents with malaise, headache and fever, exudative pharyngitis, posterior cervical node enlargement, splenomegaly, and hepatomegaly.

Diagnosis is clinical and by Monospot.  EBV immunoglobulin, atypical lymphocytes on the film and liver enzyme derangement can also be seen.

Although 5% of the general population develop an ‘amoxicillin rash’ this increases to 90% of EBV patients. This usually develops a few days after starting amoxicillin and is a maculopapular or morbilliform rash that starts on the trunk.

Treatment of EBV is supportive, with IV fluids and pain relief if needed.

CMV Tonsillitis

This is similar to EBV so should be considered if EBV-like symptoms persist but the Monospot remains negative.  Fevers and malaise are the predominant symptoms with less cervical lymphadenopathy and splenic enlargement than in EBV.  Immunoglobulin (IgM and IgG) testing can confirm the diagnosis.

HIV Tonsillitis

HIV is uncommon in children but should be considered in adolescents with high-risk behaviours.  Pharyngitis is the presenting complaint in 50-70% of patients (often presents like EBV pharyngitis).

Factors that point towards HIV tonsillitis are the absence of exudate; tonsillar hypertrophy; rash; mucocutaneous ulceration.

Consider candida and mycobacterium in the immunocompromised patient.

Bacterial Tonsillitis

Group A beta-haemolytic strep (GABHS) is the most common bacterial pharyngitis (15-30%).  It is rare under 2 years old and is usually in 5-15-year-olds.

The general agreement is that we overprescribe antibiotics for this group.

What can antibiotics achieve?

The aims of antibiotic therapy in bacterial tonsillitis are:

How can I be sure it’s bacterial and know when to prescribe antibiotics?

There are two scoring systems for assessing the likelihood of GABHS

Centor Criteria

History of fever >38°C

Tonsillar exudate

Tender anterior cervical adenopathy

Absence of cough

If 4 of the Centor criteria are met, PPV is 60%. The absence of 3 or 4 of the Centor criteria has a fairly high NPV of 80%. The recommendation is to treat with 4, don’t treat with 0-1, culture with 2 and think about treatment with 3.

However, a recent study by Rogen et al (2013) showed that the Centor criteria were not effective in predicting GABHS in children

Streptococcal Score Card (from BMJ Best Practice)

5 to 15 years

Season (late autumn, winter, early spring)

Fever (≥38.3°C)

Cervical lymphadenopathy

Pharyngeal erythema, oedema, or exudate

No symptoms of a viral upper respiratory infection (conjunctivitis, rhinorrhoea, or cough). If 5 of the criteria are met, a positive culture for GABHS is predicted in 59% of children; if 6 of the criteria are met, a positive culture is predicted in 75% of children.

Do antibiotics make a difference anyway?

GABHS has a 3-4 day natural history and is self-limiting.

Shortening the illness

Studies show that antibiotics shorten the course of the illness by 16 hours.

Preventing suppurative complications

NNT to prevent surgical intervention from complications is 200.

NNT to prevent quinsy is uncertain but actually, evidence suggests that many of these presents without a sore throat.

Preventing non-suppurative complications

No definitive evidence that antibiotics prevent glomerulonephritis.

Some evidence for antibiotics preventing rheumatic heart disease (but this was in American Marines in the 1950s).  NNT to prevent rheumatic heart disease was 63.

Is rheumatic fever really a common complication of tonsillitis?

It is now rare, and the incidence is <1 in 100,000.

Of those who do get it, only one-third get carditis and of these, only a small minority get valve dysfunction.

So when do I treat?

Antibiotics are only required in high-risk populations to prevent rheumatic heart disease.

This has to be balanced against the risk of allergy (severe penicillin allergy seen in 10-40 per 100,000), rashes and antibiotic resistance.

In many countries, treatment is not recommended.  Australia does have high-risk communities though.

High-risk populations

Patients aged 2-25 with sore throat in communities with a high incidence of acute rheumatic fever (some Indigenous communities in northern Australia and also some lower socio-economic communities)

Patients of any age with existing rheumatic heart disease

Patients with scarlet fever

If treatment is given:

Phenoxymethylpenicillin (15 mg/kg up to 500mg BD for 10 days)

Roxithromycin would be the second line treatment

Some centres use a single dose of glucocorticoid to decrease pain and swelling


Roggen I, van Berlaar G, Gordts F, Pierard D, Hubloue I, Centro criteria in children in a paediatric emergency department for what it is worth. BMJ Open, 2013;3::e002712. doi:10.1136/bmjopen-2013-002712

BMJ Best Practice, Tonsillitis

Guthrie K, My throat hurts, Life in the Fast Lane

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5 thoughts on “Tonsillitis”

  1. Great summary.

    For those in the northern hemisphere there is NICE guidance on the subject as well. (CG69 – Respiratory Tract Infections )



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