Abstract
Tonsillitis is a condition that is commonly encountered in primary care. On average 50 per 1000 patients consult their GP each year with a sore throat. Tonsillitis is a significant economic burden, with 35 000 000 days lost from work or school. Acute tonsillitis commonly affects children from the age of 4 years (highly prevalent between 4 and 8 years old) and young adults aged between 15 and 25 years old. With the emergence of multi-resistant pathogens, antimicrobial stewardship has become central to the strategies adopted by the National Institute for Health and Care Excellence in the UK.
The GP curriculum and tonsillitis
Manage primary contact with patients who have a common/important ENT, oral or facial problem, e.g. vertigo or tinnitus Demonstrate knowledge of the scientific backgrounds of symptoms, diagnosis and treatment of ENT, oral and facial conditions Understand how to recognise rarer but potentially serious conditions such as oral, head and neck cancer Understand when urgent (or semi-urgent) referral to secondary care may be indicated, e.g. in trauma, epistaxis, quinsy (peritonsillar abscess), severe croup or stridor Understand when watchful waiting and the use of delayed prescriptions are indicated Demonstrate an evidence-based approach to antibiotic prescribing Demonstrate effective strategies for dealing with parental concerns regarding ENT conditions, such as recurrent tonsillitis or otitis media with effusion, e.g. explain why antibiotics are not always indicated
Aetiology
Causative organisms of tonsillitis.
As a GP, it is important to search for patient cues that may, in some cases, unearth a hidden agenda. It has been suggested that prescribing antibiotics inappropriately may over-medicalise what is usually a self-limiting condition (Little et al., 1997). Contrary to popular belief, studies suggest that the priority for patients attending with a sore throat is not to acquire antibiotics, but rather to establish the cause of their symptoms, obtain pain relief, and receive information regarding the course of the illness (Butler, Rollnick, Pill, Maggs-Rapport, & Stott, 1998).
The clinical approach
The aim of the evaluation of patients with sore throat or acute pharyngitis is to exclude potentially dangerous causes, to identify any treatable causes, and to improve symptoms. The evaluation includes a thorough history, focused physical examination, and investigation in selected patients.
History
The history provides important information to determine whether the patient has a sore throat, or whether there is a deeper pain in the throat or neck pain. Symptoms of acute sore throat can vary between patients, and will occasionally depend on the cause. Distinguishing between a viral and bacterial cause is difficult in practice, as there is often overlap between the symptoms and signs.
Group A beta-haemolytic streptococcal (GABHS) infection usually presents with a sudden onset of sore throat, tonsillar exudate, fever, tender cervical lymphadenopathy and absence of a cough. Additional symptoms include halitosis, odynophagia, otalgia and upper airway obstructive signs, such as snoring or mouth-breathing. Viral tonsillopharyngitis, on the other hand, may have additional symptoms relating to a generalised viral upper respiratory tract infection. This includes coryza, nasal congestion, sinusitis, and hoarseness.
Children between the ages of 6 and 36 months presenting with a ‘barking cough’, hoarseness, stridor, and respiratory distress may be suffering from laryngotracheobronchitis (croup). Unilateral symptoms, such as one-sided sore throat and ipsilateral otalgia, may suggest spread of infection beyond the palatine tonsil capsule, such as a peritonsillar abscess.
Examination
It is important to appreciate that patients presenting with a sore throat may be seriously unwell and septic. As part the examination, one should inspect the patient, observing for a ‘toxic’ appearance and signs of dehydration. Vital signs and a thorough, systematic examination of the ear, nose and throat (ENT) should guide the clinician towards a diagnosis.
Drooling and an inability to take fluids orally should prompt urgent referral to secondary care for intravenous antibiotics. Drooling in children associated with fever, stridor, dysphagia and an upright posture is highly suggestive of epiglottitis, which although uncommon, can be life-threatening. In adults, although rare, acute epiglottitis has similar symptoms along with a muffled or hoarse voice. The incidence of epiglottitis has dramatically declined since routine infant vaccination with Haemophilus influenzae type b (Hib) vaccines began in 1991. These patients should not be examined; rather they should be kept calm and referred urgently to secondary care.
Otherwise, inspect the oral cavity, assessing for trismus (an inability to open the jaw) on mouth-opening. This may indicate a peritonsillar abscess or a deep neck space infection. Although a whitish-yellow membrane covering both tonsils may suggest glandular fever (infectious mononucleosis) caused by Epstein– Barr Virus (EBV) infection and a generalised erythematous, swollen appearance with exudate is consistent with GABHS infection (Fig. 1). Viral and bacterial infections are clinically indistinguishable. The presence of cough and coryzal symptoms may suggest a viral aetiology.
Clinical photograph of acute bacterial tonsillitis showing enlarged, inflamed tonsils with exudate. The uvula is central.
Look for inflammation, ulcers, masses, exudate and asymmetry within the pharynx. Persisting ulcers (longer than 3 weeks) or masses should prompt an ENT suspected cancer pathway referral. Assess the uvula, soft palate, palatine tonsils and the pharynx. If the base of the uvula is deviated, along with soft palate oedema and trismus, suspect a peritonsillar abscess.
Palpate the neck for cervical lymphadenopathy, making a note of tender lymphadenopathy. This may suggest GABHS infection. Tender, symmetrical posterior cervical lymphadenopathy suggests EBV infection (Aronson & Auwaerter, 2016), especially in teenagers or young adults with malaise, fatigue and a more persistent sore throat.
Examine the ears, looking for an erythematous, bulging tympanic membrane suggestive of acute otitis media. Restriction of neck movements should raise the suspicion of a deep neck space infection, requiring an immediate referral to ENT specialists. Abdominal examination may reveal hepatosplenomegaly in patients with glandular fever.
The combination of symptoms and epidemiologic features has been used to develop clinical scores that can be used to attempt to predict the likelihood that a sore throat is caused by GABHS infection (Breese, 1977; Centor, Witherspoon, Dalton, Brody, & Link, 1981). The absence of signs and symptoms of viral infections (e.g. coryza, conjunctivitis, cough, hoarseness, anterior stomatitis, discrete ulcerative lesions or vesicles, diarrhoea) makes a bacterial rather than a viral infection more likely.
The Centor score is a widely used and accepted clinical prediction tool that has a reasonable negative predictive value in excluding GABHS. The scoring criteria are: Tonsillar exudate; tender anterior cervical lymphadenopathy; fever over 38℃; and absence of cough. The Centor score is most useful in identifying patients in whom neither microbiological tests nor antibiotic treatment are necessary.
Modified Centor scoring.
Adapted from McIsaac, Kellner, Aufricht, Vanjaka, & Low (2004) .
Pre-test probabilities of Streptococcal infection in respect to the Modified Centor Score.
Adapted from McIsaac et al. (2004) .
Investigations
Patients with sore throat symptoms commonly visit their GP, but in most cases the cause is viral and only symptomatic treatment is needed (Hawker et al., 2014). It is vital to quickly establish that a patient’s symptoms are due to tonsillitis and not another, potentially dangerous cause of sore throat (such as a retropharyngeal abscess or acute epiglottitis).
Throat cultures are not recommended for every patient in general practice (NICE, 2015a), and are unable to differentiate between active infection and carriage (NICE, 2015a; Scottish Intercollegiate Guidelines Network, 2010). When performed properly, the sensitivity of throat swabs is 90 to 95% for GABHS (Dingle, Abbott, & Fang, 2014). Ideally when taking a throat swab, both tonsils and posterior pharyngeal wall should be vigorously swabbed without touching the tongue or buccal mucosa (Pichichero, 1995). Results take 48 hours to be reported. GABHS can be isolated from up to 30% of patients presenting with sore throats (Caserta & Flores, 2010), however, values of asymptomatic carriage range between 6 and 40% (Little & Williamson, 1996). Both cost and time limit the merits of throat swabs, but they may be useful in patients that have failed treatment, or those patients in whom a decision has been made to delay antibiotics.
Rapid antigen detection testing (RADT) is not recommended as a routine investigation for acute sore throats by NICE (NICE, 2015a), however, NHS England has recently planned to roll out a ‘sore throat test and treat’ service across pharmacies in the country over the next year. Patients will be able to visit pharmacies for RADT, and if positive, pharmacists will provide appropriate antibiotics without patients needing to see their GPs (Desmond, 2016). RADT has a specificity of greater than 95% and a varying sensitivity between 70 and 90% for GABHS. Given its high specificity and limited sensitivity, a positive RADT can be useful in establishing the diagnosis of GABHS tonsillitis, but a negative RADT does not rule it out; in these cases throat culture swabs would be beneficial (Pichichero, 1995).
A full blood count may be helpful in patients with suspected infectious mononucleosis, in immunocompromised patients, and in patients with signs or symptoms of severe infection. Raised white cell count with lymphocytosis and atypical lymphocytes is suggestive of infectious mononucleosis (IM). A positive monospot test in patients with suspected IM is diagnostic of EBV infection, however, due to low sensitivity, a negative monospot test does not rule out the diagnosis of IM. In these instances, EBV-specific antibody testing may be carried out to confirm the diagnosis.
Vaginal and cervical, or penile and rectal swabs should be considered if there is a suspicion of a gonococcal throat infection, especially in sexually active adolescents and those engaging in oral-genital sex. A human immune deficiency virus (HIV) viral load assay is indicated for patients at risk of HIV infection who have persistent tonsillopharyngitis accompanied by severe constitutional symptoms.
Red flags and serious diagnosis
Red flag symptoms.
Differential diagnosis
Scarlet fever
Scarlet fever is caused by toxin-producing strains of Streptococcus Pyogenes, a beta-haemolytic bacterium that is classified as a Group A Streptococcus. Scarlet fever is highly contagious, and is transmitted via droplets. Outbreaks in schools and other institutions where there is close contact between individuals can occur. The incubation period is usually 2–3 days. The blanching rash usually appears on the second day of the illness, beginning on the chest and spreading to the abdomen and extremities. The rash is prominent in skin creases and has a sandpaper-like texture, due to the occlusion of sweat glands. The rash persists for several days, and later (up to 3 weeks) will result in desquamation. There is an exudative tonsillopharyngitis, and there may be small red haemorrhagic spots on the hard and soft palate. The face is flushed, with circumoral pallor and a red strawberry tongue
Glandular fever (infectious mononucleosis)
EBV is the causative agent in patients typically presenting with a triad of sore throat, fever and lymphadenopathy. There is muscle ache and severe malaise out of proportion to the clinical picture (Caserta and Flores, 2010). Lymphocytosis may be apparent on full blood count and a positive monospot test is diagnostic. Ampicillin-based antibiotics should be avoided, as they may precipitate a rash. There may be splenomegaly in up to 50% of patients (Fisher & Boyce, 2005) due to lymphocytic infiltration, rendering the organ susceptible to rupture, either spontaneously or traumatically. Splenic rupture is rare (less than 0.5% of patients with IM), but its consequences can be severe (Turner and Gard, 2008). Therefore, patients should be advised to avoid activities that increase intra-abdominal pressure and contact sport for at least 4–6 weeks (Becker and Smith 2014).
HIV
HIV can cause ulcerative tonsillitis and pharyngitis with fever. It occurs after an incubation period of 3–5 weeks with symptoms of myalgia, arthralgia, lethargy, and in some people a non-itchy maculopapular rash. Lymphadenopathy develops a week later (Caserta & Flores, 2010).
Herpes simplex virus pharyngitis
Herpes simplex virus (HSV) pharyngitis presents with red, swollen tonsils that may have aphthous ulcers on their surfaces. Herpetic gingival stomatitis, herpes labialis, and hypopharyngeal and epiglottic lesions may be seen.
Complications
Peri-tonsillar abscess/quinsy
A spread of infection beyond the tonsil may lead to an abscess formation and collection of pus within the potential space between the tonsil and its containing fossa. Clinical features include unilateral sore throat, trismus, ‘hot-potato’ voice, referred otalgia and odynophagia. Treatment is in the form of aspiration/incision and drainage, and intravenous antibiotics. Rarely, these can progress to a parapharyngeal/retropharyngeal abscess, which can cause airway obstruction and mediastinal infection. Suspicion of any extracapsular spread of infection should prompt an immediate referral to ENT.
Airway obstruction
Airway obstruction is a rare complication and requires immediate referral to secondary care, where surgical intervention may be considered as an emergency. This may occur because of oedema of the soft palate and tonsils following a deep neck space infection, peritonsillar abscess or in rare circumstances, EBV infection. Common features include stridor, muffled voice, increased work of breathing and tachypnoea.
Post-Streptococcal glomerulonephritis
Post-streptococcal glomerulonephritis is an inflammatory disorder of the kidneys that can manifest 1–2 weeks after a streptococcal throat infection. Common features include dark urine, periorbital oedema, general malaise and anorexia.
Rheumatic fever
Rheumatic fever is a rare, but serious, complication of an untreated or partially treated streptococcal sore throat. Clinical features include polyarthritis affecting the larger joints, and cardiac involvement which manifests as chest pain, shortness of breath and a new murmur; typically mitral regurgitation. Valvular damage can persist long term.
Treatment options
The medical treatment of sore throats does not necessarily need to focus on the administration of antibiotics, as has historically been the case. Between 50 and 80% are due to a viral cause, and therefore, the use of antibiotics should be discouraged to reduce the risk of antibiotic resistance.
In a 2013 meta-analysis, sore throat lasted between 2 and 7 days among children who received control, placebo, or over-the-counter treatment; the sore throat resolved by day 3 in approximately 60–70% of cases (Thompson et al., 2013). The duration of symptoms was similar in children with and without GABS tonsillitis. Treatment with antibiotics improved symptoms 16 hours earlier compared with those treated with supportive care only (Spinks, Glasziou, & Del Mar, 2013). Symptom resolution was much more likely if antibiotic treatment was instigated within 2 days of symptom onset (Randolph, Gerber, DeMeo, & Wright, 1985).
Both suppurative and non-suppurative complications are uncommon, and clinical scoring does not predict the likelihood of acquiring these complications (Howie & Foggo, 1985; Little et al., 2013; Taylor & Howie, 1983). Reducing suppurative and non-suppurative complications requires treating many patients with antibiotics (Spinks et al., 2013). For example, the complication rate of acute otitis media (AOM) among those with sore throats is estimated at 0.7%, implying a number needed to benefit (NNTB) of nearly 200 to prevent one case of AOM. In low-income countries, complications are much more common, and therefore, the NNTB may be lower (Spinks et al., 2013). In both instances, there is a balance between modest levels of symptom reduction and the risk of antimicrobial resistance. In most cases, supportive management may be all that is required in the form of adequate analgesia: paracetamol and ibuprofen. Patients should also be advised to maintain adequate hydration and to rest.
Occasionally, antibiotics are recommended at first presentation to treat: marked systemic upset, those with valvular heart disease or existing rheumatic heart disease, patients with scarlet fever and for complications of tonsillitis. Patients with or without suppurative complications of tonsillitis, and who are unable to swallow, will require admission to secondary care for administration of parenteral antibiotics and fluids.
Antibiotics are recommended for patients at high risk of complications, including patients who are immunocompromised or have significant heart, lung, renal, liver or neuromuscular disease. The high-risk group includes patients with cystic fibrosis, and young children born prematurely.
Antibiotics may also be considered in patients scoring three or more on the modified Centor criteria. These patients may be provided with a prescription for delayed antibiotics, or with no antibiotics if no risk factors of severe infection are present.
The antibiotic of choice is Phenoxymethylpenicillin for 10 days. A macrolide can be used as an alternative if an allergy to penicillin exists. Ampicillin-based antibiotics should be avoided in the treatment of sore throats, as these may precipitate a widespread non-blanching maculopapular rash in the presence of glandular fever.
NICE (NICE 2015b) suggests a delayed antibiotic prescription as an alternative prescribing strategy. In this case, patients can be offered:
Reassurance that antibiotics are not needed immediately, as they are likely to make little difference to symptoms and may have side effects, such as diarrhoea, vomiting and rashes Advice about using the delayed prescription if symptoms do not settle within the expected time frame, or if a worsening occurs in the patient’s clinical status or symptoms Advice about seeking medical advice if there is a worsening in the clinical condition, despite using the delayed prescription
Ultimately, a clear explanation regarding the expected course of illness should be provided to the patient. It should be emphasised that symptoms will resolve within 7 days, and that if there is worsening of symptoms or no improvement patients should re-present for review.
The use of glucocorticoids has increased recently, but is controversial. The Infectious Disease Society of America advises against the use of steroids, however, in patients with severe throat pain and/or inability to swallow, there may be a role (Shulman et al., 2012).
In cases of recurrent tonsillitis, referral to secondary care should be discussed for consideration of tonsillectomy. Although tonsillectomy has been shown to reduce the number of sore throats and improve general health, the procedure is not without risks. A study of 33 921 patients undergoing adenotonsillar surgery in the UK between 2003 and 2004 reported a readmission rate of 3.9% and a tonsillar haemorrhage rate of 3.5% (British Association of Otorhinolaryngologists—Head and Neck Surgeons, 2005). It is important to note that although tonsillectomy can prevent recurrent episodes of tonsillitis, it will not affect recurrent sore throats from other causes. Therefore, it is vital to confirm a diagnosis of recurrent tonsillitis and rule out sore throats from other aetiologies prior to consideration of surgical management.
SIGN criteria for surgical intervention in secondary care.
It is interesting to note that a cross-sectional observational study of trends in emergency hospital admission for sore throats in the context of the number of tonsillectomies, found a 44% reduction in the overall tonsillectomy rate between 1991 and 2011. During the same study period, the admission rate to hospital for tonsillitis rose by 310%, for peritonsillar abscess by 31% and for retro/parapharyngeal abscess by 39% (Lau, Upile, Wilkie, Leong, & Swift, 2014).
Tonsillectomy may be considered on a case-by-case basis after careful consideration of the risks and benefits and a thorough discussion of the options with the patient. In cases where the diagnosis is uncertain, or there is a doubt as to the clinical significance of the sore throats, a period of active monitoring over a minimum of 6 months can be beneficial, with patients recording episodes and symptoms in a ‘sore throat diary’.
Tonsillectomy is performed under a general anaesthetic, and may involve an overnight stay in hospital. Recovery takes up to 2 weeks and patients are advised to rest; taking time off work/school. They will require regular analgesia and should maintain a good oral intake, as this has been shown to reduce recovery time and prevent infections.
Key points
Diagnosis of acute tonsillitis is clinical, and it can be difficult to distinguish viral from bacterial infections GABHS accounts for up to 30% of the cases of tonsillitis in children and adolescents The modified Centor score is a useful validated clinical prediction tool for diagnosing GABHS tonsillitis Complications of tonsillitis include peritonsillar and neck space abscesses, rheumatic fever and post-streptococcal glomerulonephritis Most cases of tonsillitis are self-limiting and do not require antibiotics Patients who fulfil the SIGN criteria, may be referred to secondary care for consideration of surgical management