What are the causes of sore throat?
Viruses are associated with 85 to 95 per cent of sore throat cases in adults. In children the incidence of viral-associated sore throat varies depending on age. Bacteria can also be associated with sore throats, but this only occurs in approximately 10 per cent of cases in younger children and adults. In children between five and 15 years, group A
§-haemolytic streptococcus is the cause in about 30 per cent of cases.
When should antibiotics be prescribed?
Nice recommends that antibiotics should not be used, or prescribing delayed, in patients with acute sore throat who are not at risk of additional complications. It is important patients are advised that antibiotics would have a limited effect on symptoms, even if the cause is bacterial. Around 40 per cent of patients will recover without treatment in three days.
Sore throats are a common and troublesome affliction for all ages. On average, they typically occur two to three times per year in adults, although dry throats may be much more common. In children this incidence may be much higher, owing to their naive immune system. The term ‘sore throat’ is a general one and encompasses a wide range of symptoms and causative agents. Therefore, a sore throat may differ greatly between individual patients based on their immune state, the duration of the sore throat, the symptoms displayed and the causative agent. Contrary to popular belief, in only a small percentage of cases is the causative agent a bacterial infection.
Causes and risk factors
The most frequent cause of sore throats is a viral infection, with viruses associated with 85 to 95 per cent of sore throat cases in adults.1
In children the incidence of viral-associated sore throat varies depending on age. For example, in children aged between five and 16 years, viruses cause 70 per cent of sore throats, whereas in children younger than five years of age, this figure is 95 per cent.1
Bacterial infection can also be associated with sore throats, but this only occurs in about 10 per cent of cases in younger children and adults. When bacteria are the cause of the sore throat, the most common bacterial cause is group A ß-haemolytic streptococcus (GABHS, also known as streptococcus pyogenes, colloquially known as strep throat).1 In children aged between five and 15 years, GABHS is the cause of sore throats in about 30 per cent of cases.1
Environmental factors, such as air conditioning, low humidity and low temperature, indoor heating, allergens and pollution may also cause dry and sore throat. A sore throat may be an indication of an underlying condition.
Examples of underlying conditions for which a sore throat may be a marker include the complications of infections, glandular fever, peritonsillar abscess, oral thrush and non-infective diseases (eg allergy and very rarely throat cancer, which is largely limited to older smokers).
Red flags and referrals
Sore throat may be a red flag for certain serious conditions. For example, in patients taking carbimazole for overactive thyroid activity, a sore throat may be one of the early signs of agranulocytosis, a severe lowering of the white blood cells.
Owing to the serious conditions that may be associated with a sore throat, pharmacists should refer a patient to a GP if:2
– the patient cannot swallow liquids
– the sore throat is recurrent or lasts more than seven days
– the patient experiences prolonged (over three weeks) or repeated bouts of hoarseness
– the patient develops a red rash
– the patient has a persistent sore throat with heavy night sweats and enlarged glands
– the patient develops earache, which does not resolve within 48 hours
– the throat is painful, has not improved within 48 hours and there are no cold or influenza symptoms
– glands in the neck are swollen with no other symptoms or fail to go down within three weeks of a sore throat clearing
– the patient has had rheumatic fever.
Pharmacists should question patients around the above criteria to establish if the sore throat could be a sign for referral to the GP, or hospital if a sore throat is associated with breathing difficulties.2
Around 40 per cent of patients will have recovered without treatment within three days and 80 per cent within seven days.3
The management of an acute sore throat therefore revolves around providing relief from the existing symptoms (eg local pain and inflammation), removal of the underlying causes and prevention of secondary complications.4 These targets can be achieved through a number of therapeutic approaches, such as analgesics, local anaesthetics, antiseptics, anti-inflammatory agents and, if required, antibiotics.
Few hard guidelines exist for the management of sore throat. One example of a treatment algorithm coming into effect in Northern Ireland is available in the full version of this article online at www.chemistanddruggist.co.uk/update.
Nevertheless, when patients present at the pharmacy, pharmacists should provide patients with general advice about their condition and give overall treatment recommendations, such as getting plenty of rest and drinking plenty of fluids.
Pharmacists should also recommend specific OTC remedies for treating acute sore throat. The range of OTC options available should allow treatment to be tailored, depending on the type of sore throat and what patients want from their therapy.
Acute sore throat OTC treatments are available in many different formulations, including tablets, sprays, gargles and lozenges Ð the latter being the most frequently used formulation within the UK. Each of the treatments has its respective advantages and disadvantages.
For example, data show that, compared with sprays and gargles, lozenges have considerable advantages in terms of the delivery of active ingredients. This is because of a prolonged delivery due to an increased mouth residence time of lozenge.5 In contrast, a proportion of throat sprays is immediately swallowed after application,5 and with gargles there is an associated gag reflex, restricting the delivery of active ingredients to only the anterior oral cavity and not all affected areas of the throat.
Oral analgesics, such as paracetamol and ibuprofen, are effective in reducing pain associated with acute sore throat.2 However, despite their efficacy in providing pain relief, oral analgesics have limited effect on sensorial aspects, such as soothing, coating, cooling and warming.
Throat lozenges, on the other hand, have been associated with many of these sensorial benefits. In addition, some contain active ingredients that possess one or a combination of antibacterial, antiviral, anti-inflammatory and local anaesthetic properties. For example, recent data have shown that the active ingredients of amylmetacresol (AMC) and 2,4-dichlorobenzyl alcohol (DCBA) throat lozenges also possess local anaesthetic properties6 in addition to some antiviral and antibacterial properties. Furthermore, a recent randomised controlled trial of the use of AMC/DCBA throat lozenges showed reduced throat soreness, an easing of difficulty of swallowing and improved functional impairment scores compared with placebo lozenges.7
Preference of treatment varies between individuals. Some patients want relief with sensorial effects, while others want more hard-hitting relief, such as powerful analgesic, anti-inflammatory or anaesthetic effects. Anaesthetic effects can be polarising for patients; a recent questionnaire survey on the use of a range of AMC/DCBA, AMC/DCBA/lidocaine, and hexylresorcinol throat lozenge formulations in healthy volunteers showed an anaesthetic effect for AMC/DCBA lozenges and a more pronounced numbing effect was reported with hexylresorcinol and lidocaine, with higher concentrations increasing the effect. Indeed, a numbing effect has previously been reported in patients taking AMC/DCBA lozenges, which contain 10mg of lidocaine.8 Lidocaine (8mg) sore throat lozenges have also been associated with improvements in pain intensity and meaningful pain relief.9 Thus, with the selection of OTC treatment options available, some patients may prefer to choose a stronger lozenge regardless of the severity of their sore throat.
When recommending a throat lozenge with local anaesthetic effects, it is important for pharmacists to point out that the action of any local anaesthetic agent may affect the perception of the temperature of hot drinks.
An additional treatment approach for acute sore throat is the use of complementary medicine. A number of traditional, herbal and complementary treatments are available and have a weight of anecdotal support for their use.
However, they are limited by their lack of strong clinical evidence. A recent review by the Cochrane Collaboration stated that the efficacy of Chinese herbal medicine for the treatment of sore throat is controversial and questionable.
Furthermore, it stated that they could not recommend any kind of Chinese medical herbal formulation as an effective remedy for sore throat.10 Owing to the possibility of interactions, it is advisable to establish if a patient has been using complementary remedies prior to recommending an OTC treatment.
Nice has developed a guidance document on antibiotic prescribing for respiratory tract infections in adults and children that includes recommendations for the management of patients with acute sore throats. The recommended strategies for prescribing antibiotics are based on the individual diagnosis of the patient, and include no, delayed or immediate prescribing.
The guideline indicates that a delayed prescribing or no prescribing strategy should be offered to patients with acute sore throat who are not at increased risk of developing complications. Because patients occasionally view antibiotics as a cure for all ills, it is important for health professionals to reassure them that antibiotics are not required as they would have limited effects on the symptoms of sore throat and may be subjected to potential side effects. Indeed, the aetiology of acute sore throat means that for the majority of cases, the cause of the sore throat will not be a bacterial infection and so treatment with antibiotics is not warranted. In cases of bacterial sore throat where antibiotics are used, the absolute benefits have been shown to be only modest and take time to show any effect. Therefore, it is important for the GP to highlight the benefits of alternatives to antibiotics and refer patients on to the pharmacist.
Alongside recommendations for OTC treatments, pharmacists may provide patients with general recommendations for the treatment of their sore throat. These include getting sufficient rest and making sure that they remain hydrated.
If a patient presents with persistent sore throat, rheumatic fever or indeed any of the signs mentioned earlier, they should be referred back to the GP or hospital.The proposed sore throat algorithm is available in the full version of this article online at www.chemistanddruggist.co.uk/update
Damien McNally is a GP partner in Belfast
– Nice Clinical Guideline 69. Respiratory tract infections Ð antibiotic prescribing. Prescribing of antibiotics for self-limiting respiratory tract infections in adults and children in primary care. July 2008. www.nice.org.uk/nicemedia/live/ 12015/41323/41323.pdf).
1. Worrall GJ. Can Fam Physician 2007; 53:1961Ð1962.
2. Marshall S. Pharm J. 2008;280:127Ð130.
3. Del Mar CB, et al. Cochrane Database Syst Rev. 2004;(2): CD000023. Review. Update in: Cochrane Database Syst Rev. 2006; (4): CD000023
4. Kelly F. Australian Pharmacist 2008;394Ð97.
5. Limb M, et al. Int J Clin Pract. 2009; 63:606Ð612.
6. Buchholz V, et al. Naunyn Schmiedebergs Archiv Pharmacol 2009; 380:161Ð168.
7. McNally D, et al. Int J Clin Pract. 2010;64:194Ð207.
8. Chan CK, et al. Surg Endosc. 2010; 24:897Ð901.
9. Wonnemann M, et al. Arzneimittel-Forschung (Drug Research). 2007; 57:689?697.
10. Shi Y, et al. Cochrane Database Syst Rev. 2007;18;(3): CD004877.
Which patients with a sore throat should be referred to their GP? Which ingredients of throat lozenges have been shown to be most effective? What are the Nice recommendations for the treatment of sore throat with antibiotics?
This article discusses the treatment of sore throats and includes information about causes and risk factors and when to refer a patient. It also describes the treatment and advice pharmacists can offer and the current rationale behind antibiotic prescribing.
– Read more about the symptoms and treatment of sore throat on the Patient UK website at http://tinyurl.com/sorethroat01.
– Find out more about the management of acute sore throat from the Clinical Knowledge Summaries website at http://tinyurl.com/sorethroat02.
– Revise your knowledge of the OTC products available for the treatment of sore throat from the C+D Guide to OTC Medicines. Review those stocked in your pharmacy, think about which ones you would recommend and make sure your counter staff are aware of your choices.
Are you now confident in your knowledge of the symptoms and treatment of acute sore throat? Could you advise patients about drug and non drug treatment and explain why antibiotics may not be necessary?