Acute pharyngitis (sore throat): causes, treatment and when antibiotics help

Sore throat is a symptom: pain at the back of the mouth. NICE Clinical Knowledge Summaries describes acute pharyngitis as inflammation of the part of the throat behind the soft palate, called the oropharynx, and distinguishes it from tonsillitis, which is inflammation of the tonsils. In practice the two overlap and often occur together.

It is among the commonest reasons for seeking primary care. NICE says acute throat infections most commonly occur in people aged 5 to 24 years. The NHS describes sore throats as very common and usually nothing to worry about, normally getting better by themselves within a week.

The NHS says sore throats are usually caused by viruses such as colds or flu, or by smoking, and only very occasionally by bacteria. NICE lists the common causes in primary care as the common cold, influenza, streptococcal infection and infectious mononucleosis (glandular fever), with HIV, gonococcal pharyngitis and diphtheria as less common causes.

Non-infectious causes are uncommon but include physical irritation from gastro-oesophageal reflux or chronic cigarette smoke, and hayfever. Where a bacterial cause is a possibility, clinicians use scoring tools such as FeverPAIN and Centor to help decide, as set out below.

The NHS lists a painful throat, especially when swallowing, a dry or scratchy feeling, redness at the back of the mouth, bad breath, a mild cough and swollen neck glands. Children get similar symptoms but may also have a high temperature and seem less active. When the tonsils are involved there may be white patches or pus spots, earache, headache and tiredness, as described by NHS inform.

Persistent symptoms beyond a week, or a mouth ulcer or lump in the mouth or neck that lasts more than 3 weeks, are reasons for review according to the NHS.

Because most episodes are viral, the aim is comfort while the illness runs its course. The NHS suggests gargling with warm salty water (children should not try this), drinking plenty of water, eating cool or soft foods, avoiding smoking and smoky places, and resting. Sucking ice cubes or lollies can soothe, though small hard sweets should not be given to young children because of the choking risk.

A pharmacist can advise on paracetamol or ibuprofen, medicated lozenges containing a local anaesthetic, antiseptic or anti-inflammatory, and anaesthetic spray, although the NHS says there is little proof sprays help on their own. Do not give aspirin to children under 16. NICE advises regular paracetamol or ibuprofen for pain and fever and adequate fluid intake until discomfort and swelling subside.

The NHS says you do not normally need antibiotics for a sore throat, because they will not usually relieve symptoms or speed recovery, and they are given by a pharmacist or GP only if a bacterial infection is possible. NICE CKS says that clinical scoring systems, FeverPAIN and Centor, should be used to help decide whether to prescribe, and that recovery rates are similar whether or not the sore throat is caused by streptococcus.

A swab may be taken if a bacterial cause is suspected, and a blood test for glandular fever may be suggested in teenagers or adults with severe or persistent symptoms. If antibiotics are given they must be completed as directed. For recurrent tonsillitis, NICE describes frequency thresholds, more than 7 episodes in a year, 5 a year for 2 years or 3 a year for 3 years, at which specialist assessment for tonsillectomy is considered.

The NHS says to call 999 or go to A&E if you or your child have difficulty breathing or cannot swallow, are drooling, are making a high-pitched noise as you breathe (stridor), or have severe symptoms that are getting worse quickly. NICE says people with stridor, breathing difficulty or dehydration should be admitted immediately.

Ask for an urgent GP appointment or get advice from NHS 111 if you are worried, have a very high temperature or feel hot, cold or shivery, show signs of dehydration, or have a weakened immune system, for example because of diabetes or chemotherapy. A sore throat that has not improved after a week, that keeps coming back, or a child under 5 needing help, should go to a GP.