Sore throat

A 16 year old boy presents with a sore throat for three days. He has also felt feverish and thinks that the glands in his neck have swollen up again. This is the third similar presentation in the last year. 

Sore throat is one of the most common presentations to general practice and is most prevalent in the 5-10 and 15-25 age groups. It is most commonly caused by infection. 

Causes of sore throat

Common causes 

Viral:

• Rhinovirus, coronavirus, parainfluenzae – the common cold
• Influenza types A and B
• Adenovirus
• Glandular fever (infective mononucleosis) – caused by Ebstein Barr virus. 

Bacterial 

• Streptococcal – group A beta-haemolytic streptococcus is the most common, but group C and D can present as sore throat.
• Quinsy (peritonsilar abscess) 

Rare causes

• Oropharnygeal candida
• Laryngeal cancer
• Epiglottitis 
• Diptheria
• HIV infection

History, examination and investigation   

The aim is to determine the cause of the sore throat to guide treatment and identify which should be referred to secondary care. It is particularly important to determine if antibiotics are indicated. 

Pattern of sore throat

• Duration
• Age of patient
• Infectious contacts

Associated features

• Fever
• Cervical lymphadenopathy
• Presence of cough
• Nasal symptoms
• Malaise and headache

Red flags 

• Pain >3 weeks, weight loss, smoker aged over 50. 

Examination

As the diagnosis is often made clinically a thorough examination is required and should include:

• Temperature
• Pulse
• Oxygen saturations
• Blood pressure
• Cervical lymph nodes
• Throat and ear examination (do not examine throat is epiglottis is suspected)
• Skin to look for rash
• Abdomen – tenderness and splenomegaly is seen in glandular fever

As this usually gives the diagnosis further investigation is rarely required on initial presentation. Throat swabs should not routinely be taken. If glandular fever is suspected a blood test may be appropriate for antibodies. 

Diagnosis

It can be difficult in practice to distinguish between viral and bacterial causes as many of the features overlap  

Viral – Common cold – usually a mild illness associated with coryzal symptoms. Mild redness and oedema of pharynx that lasts about 3-4 days.  

Influenza – a more severe illness with associated fever, malaise, headache, muscle aches. Mild redness and swelling of pharynx. 

Bacterial – Streptococcal – variable severity, can be very painful with fever, red and oedematous pharynx and enlarged tonsils with exudate. Enlarged cervical lymph nodes. Can be associated with scarlet fever which produces a red, sand-paper type rash that usually starts on the chest before moving to the extremities. Peeling of the skin may occur later. The tongue may be white with enlarged papillae “strawberry tongue”.

Influenzae – can cause epiglottis, a life-threatening rapid swelling of the throat. Clinical features include fever, stridor and shortness of breath.

Glandular fever – Sore throat, fever and lymphadenopathy. Severe for 3-5 days then resolves over 7-10 days. Significant malaise. Enlarged tonsils. Splenomegaly occurs in 50% of patients.  

Quinsy (peritonsilar abscess)

Usually fever, malaise and very painful throat. Unilaterally enlarged tonsil with deviation of uvula. 

Management   

• Admit patients who have signs of sepsis, are dehydrated or have significant breathing difficulties. 
• If epiglottis is suspected, the throat should not be examined as it could cause airway obstruction and the patient should be referred immediately to A&E.  
• Patients who have a suspected quinsy should be referred immediately to ENT as they often require drainage of the abscess. 
• Distinguishing between the different causes of sore throat that do not need admission is challenging, especially in the early stages and the vast majority will recover within one week without antibiotics. Glandular fever usually resolves within 2 weeks. 
• Patients who are immunosuppressed such as those on DMARDs or chemotherapy, patients with HIV or taking carbimazole and are not requiring admission should have their FBC taken to look for neutropenia, antibiotics considered and the case discussed with their specialist.   
• If well they should be advised about simple analgesia to help with pain and fever as well as the importance of keeping hydrated. 
• Antibiotics should only be prescribed for tonsillitis if 3/4 CENTOR criteria are met because 3 or more criteria suggests a bacterial cause.   
• The local prescribing formulary is helpful in guiding antibiotic choice and phenoxymethylpenicillin is often used. Avoid amoxicillin as it can cause a rash in glandular fever. 
• If the patient suffers recurrent tonsillitis that is significantly affecting schooling or work they may be considered for tonsillectomy according to local policies. 
• Give the patient safety-netting advice and if the patient does not recover as expected consider an alternative diagnosis, including glandular fever and have a low threshold for referring for suspicion of throat cancer.
  

The patient has a temperature of 38.5, enlarged cervical LN, no cough and red, inflamed tonsils with exudate. CENTOR score 4/4. He was prescribed phenoxymethylpenicillin and the sore throat resolved within a few days. A referral to ENT for a tonsillectomy was considered as the patient has been missing significant amounts of their schooling due to the infections.

Exam preparation

Practice taking histories and examining patients with sore throats to gain skills in deciding if a sore throat requires antibiotics

Discuss the referral criteria for a tonsillectomy with a patient who suffers one episode of tonsillitis per year. 

References

Clinical knowledge summary – sore throat. https://cks.nice.org.uk/sore-throat-acute#!topicsummary

Lothian Joint Formulary – antibiotic guidance https://www.ljf.scot.nhs.uk/LothianJointFormularies/Adult/5.0/Pages/default.aspx 

Ref-help – ENT – criteria for tonsillectomy. https://apps.nhslothian.scot/refhelp/ENTADULT