Sore throat is a symptom resulting from inflammation of the upper respiratory tract. Four regions are principally involved - the pharynx, the larynx, the tonsils and (rarely) the epiglottis.
Because sore throat is a symptom rather than a specific condition, estimates of incidence vary. The symptom is in any case likely to be under-reported, as it is often self-limiting and a clinician may not be consulted.
Sore throat is usually due to a viral infection. Viruses commonly implicated include rhinovirus, coronavirus, influenza and parainfluenza viruses and adenovirus. In many cases, a sore throat is associated with the common cold. It may also be a symptom of influenza, or of infectious mononucleosis (glandular fever).
The most common bacterial agent is Group A beta-haemolytic streptococcus (GABS). In children, it accounts for 20-40% of cases of sore throats; in adults around 10%[2, 3]. Asymptomatic nasal carriage of Group A streptococci is very common, especially in very young children.
The symptom of soreness on swallowing may be accompanied by fever and symptoms of upper respiratory tract infection such as headache, malaise, rhinitis and cough. Hoarseness may be present if there is laryngeal involvement.
Specific enquiry should be made about:
- Duration and severity of symptoms.
- Any self-medication/over-the-counter treatment.
- History of any comorbidities, previous risk factors, relevant past history.
- Feeling systemically unwell.
Examination of the throat using a tongue depressor should not be attempted in patients with stridor, as epiglottitis may be present and examination may provoke laryngeal obstruction. Drooling, leaning forward and high temperature may also be suggestive of epiglottitis. Since the introduction of Haemophilus influenzae type B (Hib) vaccination, acute epiglottitis is now extremely rare in children in the UK.
In other cases of sore throat, examination of the throat may reveal redness of the pharynx and tonsils, enlargement of the tonsils, presence of exudate and enlarged tender cervical lymph glands.
Differentiating a viral sore throat from that caused by GABS on the basis of examination is difficult. The Centor Criteria were developed to help predict bacterial infection clinically:
- Tonsillar exudate.
- Tender anterior cervical lymph nodes.
- Absence of cough.
- History of fever.
A Centor score is out of 4 depending on how many of these are present. The presence of three or four of these signs (Centor score 3-4) suggests that the possibility of the patient having GABS is 40-60% and that antibiotic therapy may be beneficial. Conversely, patients without three or four of the signs imply an 80% chance of a viral infection.
A scarlet fever-like rash (red punctate skin eruption, prominent in the skin creases), a flushed face, circumoral pallor and a 'strawberry tongue' suggest the possibility of a streptococcal infection. Recurrent sore throat with fever and lymphadenopathy may suggest glandular fever, particularly in young people.
- Coxsackievirus infection (hand foot and mouth disease, herpangina).
- Infectious mononucleosis.
- Malignancy (pharynx, tonsils, larynx).
- Kawasaki disease.
- Diphtheria (very rare since immunisation).
- Herpetic pharyngitis.
- Gonococcal or chlamydial pharyngitis.
- Investigation in primary care is not usually necessary. Some authorities recommend investigation, as this reduces the overdiagnosis of bacterial sore throat. However, in the context of UK general practice, the turnaround time for swab and serum results makes it unlikely that the results would make much difference to the immediate management of the patient. However, if symptoms and/or signs are prolonged, severe or atypical, investigation should be considered.
- Throat swabs are not advised for routine investigation of sore throats but may be helpful in high-risk groups, or where there is treatment failure.
- Rapid antigen tests may be helpful but research shows no clear benefit over using a clinical score alone[2, 6]. They are currently not universally available in primary care.
- FBC and glandular fever screening test - these may be helpful if glandular fever is suspected.
- Antistreptolysin O (ASO) titres - these may be useful in excluding recent streptococcal infection in patients who are systemically unwell or have prolonged symptoms.
It should be remembered that sore throat is a symptom of an underlying condition and efforts should be made to make an accurate diagnosis before considering treatment. For further details, see separate Tonsillitis, Laryngitis and Epiglottitis articles.
- Reassure people that a sore throat is usually a self-limiting condition and usually resolves with or without antibiotic treatment within a week.
- Advise the use of paracetamol and/or ibuprofen to relieve symptoms of pain and fever as required.
- Advise fluid intake should be adequate to avoid dehydration.
- Advise that some people find throat lozenges, hard boiled sweets, ice, or flavoured frozen desserts (such as ice lollies) provide symptomatic relief. There is some evidence for use of some lozenges but little for benzydamine gargles and none for zinc lozenges, herbal remedies or acupuncture[8, 9, 10].
- Give safety-netting advice, advising the person to return if symptoms do not improve or are getting worse, and to seek urgent medical advice if they:
- Develop difficulty breathing or stridor.
- Start to drool.
- Develop a muffled voice.
- Develop severe pain.
- Develop dysphagia.
- Become unable to swallow adequate fluids.
- Become systemically very unwell.
The National Institute for Health and Care Excellence (NICE) has recently released guidelines for this and recommends three possible options:
- No antibiotics. In this case, people should be advised that antibiotics are likely to make little difference to symptoms and may make things worse due to side-effects. They should be advised to return for further assessment if their condition persists or worsens.
- Delayed antibiotics. People should be advised as above that antibiotics are not currently indicated but that if the situation changes they may be used. They may consider using the antibiotic if the sore throat has not settled within a week as expected or if symptoms worsen. They should be given the option of returning for reassessment and be advised they should do so if symptoms continue to worsen despite using the antibiotic prescription. In the absence of features suggesting immediate prescription below, consider a two-day or three-day delayed prescription for people with a sore throat and a Centor score of 3 or 4.
- Immediate prescription of antibiotics. This option should be offered to people who:
- Are systemically very unwell.
- Have signs of serious illness and/or complications such as peritonsillar abscess or cellulitis.
- Are immunosuppressed.
- Have valvular heart disease.
- Have a significant comorbidity (eg, heart, lung, renal, liver or neuromuscular disease, cystic fibrosis).
A discussion with patients/parents/carers should take place as to which strategy is best for individual patients. This decision should be based on a clinical assessment of severity and the presence or absence of three or more Centor Criteria (presence of tonsillar exudate, tender anterior cervical lymphadenopathy or lymphadenitis, history of fever and an absence of cough). Reassessment should be offered if the condition does not settle or if it worsens.
A Cochrane review found that antibiotics shorten the duration of pain symptoms by an average of about one day and can reduce the chance of rheumatic fever by more than two thirds in communities where this complication is common. It also found other complications (such as otitis media, quinsy and sinusitis and probably acute glomerulonephritis ) associated with sore throat are also reduced through antibiotic use. In high-income countries where complications such as rheumatic fever are uncommon, the number needed to treat is much greater and many individuals need to be treated with antibiotics to prevent one complication, with implications to cost and antibiotic resistance.
When an antibiotic is required, phenoxymethylpenicillin for ten days should be the first-line choice, with erythromycin or clarithromycin for five days as second-line if there is a history of allergy to penicillin. Amoxicillin or ampicillin should be avoided, especially in adolescents and young adults because, if the diagnosis is in fact glandular fever, it will produce a rash, even in the absence of allergy to penicillin.
Clinical Editor's comments (October 2017)
Dr Hayley Willacy draws your attention to the recent information in the BMJ regarding corticosteroid prescription for acute sore throat. Corticosteroids represent an additional therapeutic option for symptom (pain) relief. Oral dexamethasone (single dose of 10 mg for adults and 0.6 mg/kg, maximum 10 mg for children) was the most common intervention followed by single dose intramuscular injection of dexamethasone. The stimulus for this review was the recent TOAST (Treatment Options without Antibiotics for Sore Throat) trial, which randomised over 500 patients with sore throat presenting to their primary care clinician who were not initially prescribed antibiotics; the TOAST authors reported beneficial effects of corticosteroids. The studies reported few adverse effects, with no apparent increase in events in patients treated with corticosteroid. In the light of this new potentially practice-changing evidence, the latest Cochrane review has also been updated.
Urgent same day referral is indicated if there is:
- Respiratory difficulty.
- Severe suppurative complications (local abscess or cellulitis, which may compromise the airway).
- Severe systemic illness.
- Suspected Kawasaki disease or epiglottitis.
Assess urgently and/or seek specialist advice in those who are immunocompromised. Urgent FBC should be done and medication such as carbimazole or disease-modifying antirheumatic agents should be withheld pending FBC results and specialist advice.
Consider routine referral for consideration of tonsillectomy as follows:
- Adults who have had five or more severe (disabling and causing loss of normal ability to function) episodes per year of sore throat due to tonsillitis. This should have been documented clinically, rather than taking a history of five episodes of reported sore throat.
- Children who have had five or more episodes of acute sore throat per year, documented by the parent or clinician, where:
- Symptoms have been a problem for at least a year.
- The episodes are severe, ie they disrupt the child's normal behaviour or functioning.
- Advantages and disadvantages have been discussed, including the possibility of spontaneous resolution.
- Children have sleep apnoea with daytime drowsiness and failure to thrive.
- Otitis media.
- Peritonsillar abscess (quinsy).
- Cervical adenitis.
- Scarlet fever.
- Streptococcal toxic shock syndrome (rare).
- Lemierre's syndrome (rare - acute septicaemia and jugular vein thrombosis secondary to infection with Fusobacterium spp.).
- Rheumatic fever (rare in developed countries but still quite prevalent in developing countries).
- Post-streptococcal glomerulonephritis.
- Guttate psoriasis - may flare up in the presence of a streptococcal infection.
90% of cases of sore throat are better within a week (whether treated with antibiotics or not) and irrespective of whether the cause is viral or streptococcal. In 40% symptoms have settled within three days.
Further reading and references
Spurling GK, Del Mar CB, Dooley L, et al; Delayed antibiotics for respiratory infections. Cochrane Database Syst Rev. 2013 Apr 30(4):CD004417. doi: 10.1002/14651858.CD004417.pub4.
Aalbers J, O'Brien KK, Chan WS, et al; Predicting streptococcal pharyngitis in adults in primary care: a systematic review of the diagnostic accuracy of symptoms and signs and validation of the Centor score. BMC Med. 2011 Jun 19:67. doi: 10.1186/1741-7015-9-67.
Cohen JF, Bertille N, Cohen R, et al; Rapid antigen detection test for group A streptococcus in children with pharyngitis. Cochrane Database Syst Rev. 2016 Jul 47:CD010502. doi: 10.1002/14651858.CD010502.pub2.
Sore throat - acute; NICE CKS, July 2015 (UK access only)
DeMuri GP, Wald ER; The Group A Streptococcal Carrier State Reviewed: Still an Enigma. J Pediatric Infect Dis Soc. 2014 Dec3(4):336-42. doi: 10.1093/jpids/piu030. Epub 2014 Apr 30.
Respiratory tract infections (self-limiting): prescribing antibiotics; NICE Clinical Guideline (July 2008)
Little P, Hobbs FD, Moore M, et al; Clinical score and rapid antigen detection test to guide antibiotic use for sore throats: randomised controlled trial of PRISM (primary care streptococcal management). BMJ. 2013 Oct 10347:f5806. doi: 10.1136/bmj.f5806.
Management of sore throat and indications for tonsillectomy; Scottish Intercollegiate Guidelines Network - SIGN (April 2010)
Pelucchi C, Grigoryan L, Galeone C, et al; Guideline for the management of acute sore throat. Clin Microbiol Infect. 2012 Apr18 Suppl 1:1-28. doi: 10.1111/j.1469-0691.2012.03766.x.
McNally D, Shephard A, Field E; Randomised, double-blind, placebo-controlled study of a single dose of an amylmetacresol/2,4-dichlorobenzyl alcohol plus lidocaine lozenge or a hexylresorcinol lozenge for the treatment of acute sore throat due to upper respiratory tract infection. J Pharm Pharm Sci. 201215(2):281-94.
Oxford JS, Leuwer M; Acute sore throat revisited: clinical and experimental evidence for the efficacy of over-the-counter AMC/DCBA throat lozenges. Int J Clin Pract. 2011 May65(5):524-30. doi: 10.1111/j.1742-1241.2011.02644.x.
Sore throat (acute): antimicrobial prescribing; NICE Guideline (Jan 2018)
Spinks A, Glasziou PP, Del Mar CB; Antibiotics for sore throat. Cochrane Database Syst Rev. 2013 Nov 511:CD000023.
Sadeghirad B, Siemieniuk RAC, Brignardello-Petersen R, et al; Corticosteroids for treatment of sore throat: systematic review and meta-analysis of randomised trials. BMJ. 2017 Sep 20358:j3887. doi: 10.1136/bmj.j3887.
Nahary L, Tamarkin A, Kayam N, et al; An investigation of antistreptococcal antibody responses in guttate psoriasis. Arch Dermatol Res. 2008 Sep300(8):441-9. Epub 2008 Jul 22.