Sore Throats

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. General practices taking part in the Fourth National Morbidity Survey reported a consultation rate of 0.1 per capita, annually.¹
Sore throat is usually due to a viral infection. The commonest bacterial agent is Group A beta-haemolytic streptococcus (GABHS).² One general practice study found an asymptomatic carrier rate for GABHS of 2.2%, highest in the under-14 age group.³

History

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
• Presence of trismus
• Feeling systemically unwell
• Dysphagia
• Rash
• Stridor

Examination

• Examination of the throat using a tongue depressor should not be attempted in patients with stridor, as epiglottis may be present, and examination may provoke laryngeal obstruction.
• 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 GABHS on the basis of examination is difficult. The Centor criteria may be helpful in this respect:²
  • Tonsillar exudate
  • Tender anterior cervical lymph nodes
  • Absence of cough
  • History of fever
• The presence of three or four of these signs suggest that the possibility of the patient having GABHS is 40-60%. Conversely, patients without three or four of the signs imply an 80% chance of a viral infection.²
• Centor criteria may also be helpful in managing patients with tonsillitis. The presence of three out of four of the signs increases the possibility of quinsy to 1:60 compared to 1:400 for patients who do not.
• 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.

• Coxsackie virus infection
• Infectious mononucleosis
• Malignancy (pharynx, tonsils, larynx)
• Diphtheria (very rare since immunisation)
• HIV

• Investigation in primary care is not usually necessary. Some authorities recommend investigation as this reduces the over-diagnosis of bacterial sore throat, but in the context of UK general practice the turn-around time for swab and serum results makes it unlikely that the results would make much difference to the immediate management of the patient.⁵ However, if symptoms and/or signs are prolonged, severe or atypical, investigation should be considered.
• Throat swab - this may be helpful if Centor criteria suggest bacterial infection or there is exudation or excessive erythema.
• Full blood count 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 our records on Laryngitis and Epiglottitis.

Non-drug

• Sore throat is usually a self-limiting condition.
• The patient should be advised to rest and avoid social contact to avoid transmitting the infection.

Drug

• Antipyretic analgesics like paracetamol and ibuprofen are of value.
• Gargles are anecdotally helpful but the evidence base is lacking.
• Antibiotics - a Cochrane Review found that there was a trend for protection against acute glomerulonephritis by antibiotics, but insufficient cases were recorded to be sure of this effect.⁶ Several studies found benefit from antibiotics for acute rheumatic fever, which reduced this complication but rheumatic fever is rare in Western societies in the 21st century. Antibiotics reduced the incidence of acute otitis media to about one quarter compared with placebo and reduced the incidence of acute sinusitis to about a half of that in the placebo group. The incidence of quinsy was also reduced. Symptoms of headache, sore throat and fever were reduced by antibiotics to about a half but the greatest time for this to be evident was around 3.5 days when the symptoms of about 50% of untreated patients had settled. The review concluded that antibiotics confer relative benefits in the treatment of sore throat but the absolute benefits are modest and at the cost of treating many with antibiotics who will derive no benefit. Antibiotics shorten the duration of symptoms, but by a mean of only 1 day about half way through the illness, and by about 16 hours overall.
• For adult patients requiring antibiotics, phenoxymethylpenicillin 500 mg two to four times daily for 10 days is the first choice. Erythromycin 500 mg twice daily or 250 mg four times daily for 10 days is an alternative for patients allergic to penicillin. Lower doses will be required for children.
• Erythromycin can also be used for treatment failures, which do occur with penicillin, and the course need only be five days. 5% to 35% of patients do not have bacteriological eradication.⁵ This may be due to to commensal infection with bacteria that produce beta lactamase.⁷
• Amoxicillin or ampicillin should be avoided, especially in adolescents and young adults, because if the diagnosis is really glandular fever it will produce a rash, even in the absence of allergy to penicillin.
• Delayed prescriptions - a randomised controlled trial across 11 general practices found that 69% of patients given a delayed prescription did not use it.
• There were no differences in the number of patients who returned within two weeks or suffered complications, irrespective of whether they were given no treatment, a prescription for antibiotics, or a delayed prescription. At one year, 38% of patients given antibiotics returned with a subsequent sore throat compared to 27% who were given a delayed prescription or no treatment.⁸

Hospital admission

NICE have produced guidance on the referral of children with recurrent episodes of acute sore throat, up to the age of 15 years.⁹

• Otitis media
• Sinusitis
• Peritonsillar abscess (quinsy)
• Cervical adenitis
• Scarlet fever
• Streptococcal toxic shock syndrome (rare)
• Non-suppurative complications (rare in developed countries, but are still a problem in developing countries)
• Rheumatic fever
• Post-streptococcal glomerulonephritis
• Guttate psoriasis - may flare up in the presence of a streptococcal infection¹⁰

One study found that symptoms settled in 40% of patients within 3 days, and 80% of patients within one week, irrespective of whether the cause was viral or streptococcal.⁶