Abstract
Introduction
About 10% of people present to primary healthcare services with sore throat each year. The causative organisms of sore throat may be bacteria (most commonly Streptococcus) or viruses (typically rhinovirus), although it is difficult to distinguish bacterial from viral infections clinically.
Methods and outcomes
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of interventions to reduce symptoms of acute infective sore throat? What are the effects of interventions to prevent complications of acute infective sore throat? We searched: Medline, Embase, The Cochrane Library, and other important databases up to January 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
Results
We found 8 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
Conclusions
In this systematic review we present information relating to the effectiveness and safety of the following interventions: antibiotics, corticosteroids, non-steroidal anti-inflammatory drugs, paracetamol, and probiotics.
Key Points
Sore throat is an acute upper respiratory tract infection that affects the respiratory mucosa of the throat.
About 10% of people present to primary healthcare services with sore throat each year.
The causative organisms of sore throat may be bacteria (most commonly Streptococcus) or viruses (typically rhinovirus), but it is difficult to distinguish bacterial from viral infections clinically.
NSAIDs may reduce the pain of sore throat at 24 hours or less, and at 2 to 5 days.
NSAIDs are associated with gastrointestinal and renal adverse effects.
Paracetamol seems to effectively reduce the pain of acute infective sore throat after a single dose, or regular doses over 2 days.
Antibiotics can reduce the proportion of people with symptoms associated with sore throat at 3 days.
Reduction in symptoms seems greater for people with positive throat swabs for Streptococcus than for people with negative swabs.
Antibiotics are generally associated with adverse effects such as nausea, rash, vaginitis, and headache, and widespread use may lead to bacterial resistance.
Antibiotics may also reduce suppurative and non-suppurative complications of group A beta-haemolytic streptococcal pharyngitis, although non-suppurative complications are rare in industrialised countries.
Corticosteroids added to antibiotics may reduce the severity of pain from sore throat in adults compared with antibiotics alone. Effects in children are uncertain.
Most trials used a single dose of corticosteroid.
However, data from other disorders suggest that long-term use of corticosteroids is associated with serious adverse effects.
Super-colonisation with Streptococcus isolated from healthy individuals apparently resistant to infections from Streptococcus may reduce recurrence of sore throat, although there is currently no evidence to suggest it may treat symptoms of acute sore throat.
About this condition
Definition
Sore throat is an acute upper respiratory tract infection that affects the respiratory mucosa of the throat. Since infections can affect any part of the mucosa, it is often arbitrary whether an acute upper respiratory tract infection is called "sore throat" ("pharyngitis" or "tonsillitis"), "common cold", "sinusitis", "otitis media", or "bronchitis" (see figure 1 ). Sometimes, all areas are affected (simultaneously or at different times) in one illness. In this review, we aim to cover people whose principal presenting symptom is sore throat. This may be associated with headache, fever, and general malaise. Suppurative complications include acute otitis media (most commonly), acute sinusitis, and peritonsillar abscess (quinsy). Non-suppurative complications include acute rheumatic fever and acute glomerulonephritis.This review does not include people with previous rheumatic fever or previous glomerulonephritis, who are importantly different from the general population of people with sore throats. It also does not include people who are clinically seriously unwell (as these people are typically not included in the primary studies).
Figure 1.
Confusion and overlap in the classification of acute respiratory infections.
Incidence/ Prevalence
There is little seasonal fluctuation in sore throat. About 10% of the Australian population present to primary healthcare services annually with an upper respiratory tract infection consisting predominantly of sore throat. This reflects about one fifth of the overall annual incidence. However, it is difficult to distinguish between the different types of upper respiratory tract infection. A Scottish mail survey found that 31% of adult respondents reported a severe sore throat in the previous year, for which 38% of these people visited a doctor.
Aetiology/ Risk factors
The causative organisms of sore throat may be bacteria (Streptococcus, most commonly group A beta-haemolytic, but sometimes Haemophilus influenzae, Moraxella catarrhalis, and others) or viruses (typically rhinovirus, but also coronavirus, respiratory syncytial virus, metapneumovirus, Epstein–Barr virus, and others). It is difficult to distinguish bacterial from viral infections clinically. Features thought to indicate Streptococcus infection are: fever >38.5 °C, exudate on the tonsils, anterior neck lymphadenopathy, and absence of cough. Sore throat can be caused by processes other than primary infections, including GORD, physical or chemical irritation (e.g., from nasogastric tubes or smoke), and occasionally hay fever. However, we consider only primary infections in this review.
Prognosis
The untreated symptoms of sore throat disappear by 3 days in about 40% of people, and untreated fevers in about 85%. By 1 week, 85% of people are symptom free. This natural history is similar in Streptococcus-positive, Streptococcus-negative, and untested people.
Aims of intervention
To relieve symptoms and to prevent suppurative and non-suppurative complications of sore throat.
Outcomes
Symptom severity: reduction in severity and duration of symptoms (sore throat pain, general malaise, headache, and fever); prevention of complications: reduction in suppurative complications (acute otitis media, acute sinusitis, and quinsy) and non-suppurative complications (acute rheumatic fever and acute glomerulonephritis); recurrence: recurrence of symptoms, time off work or school; patient satisfaction; healthcare utilisation; adverse effects of treatment.
Methods
Clinical Evidence search and appraisal January 2010. The following databases were used to identify studies for this systematic review: Medline 1966 to January 2010, Embase 1980 to January 2010, and The Cochrane Database of Systematic Reviews 2009, Issue 4 (1966 to date of issue). An additional search within The Cochrane Library was carried out for the Database of Abstracts of Reviews of Effects (DARE) and the Health Technology Assessment (HTA) database. We also searched for retractions of studies included in the review. Abstracts of the studies retrieved from the initial search were assessed by an information specialist. Selected studies were then sent to the contributor for additional assessment, using predetermined criteria to identify relevant studies. Study design criteria for inclusion in this review were: published systematic reviews of RCTs and RCTs in any language. RCTs had to contain 20 or more individuals, of whom 80% or more were followed up. Open trials were included if the outcomes were objective (otherwise all studies described as "open", "open label", or "non-blinded" were excluded). There was no minimum length of follow-up required to include studies. We included systematic reviews of RCTs and RCTs where harms of an included intervention were studied applying the same study design criteria for inclusion as we did for benefits. In addition we use a regular surveillance protocol to capture harms alerts from organisations such as the FDA and the MHRA, which are added to the reviews as required. We excluded RCTs that only provided data about bacteriological studies of the throat, because bacteriological cure is not a clinically useful outcome for spontaneously remitting illness. To aid readability of the numerical data in our reviews, we round many percentages to the nearest whole number. Readers should be aware of this when relating percentages to summary statistics such as relative risks (RRs) and odds ratios (ORs). We have performed a GRADE evaluation of the quality of evidence for interventions included in this review (see table). The categorisation of the quality of the evidence (high, moderate, low, or very low) reflects the quality of evidence available for our chosen outcomes in our defined populations of interest. These categorisations are not necessarily a reflection of the overall methodological quality of any individual study, because the Clinical Evidence population and outcome of choice may represent only a small subset of the total outcomes reported, and population included, in any individual trial. For further details of how we perform the GRADE evaluation and the scoring system we use, please see our website (www.clinicalevidence.com).
Table.
GRADE Evaluation of interventions for Sore throat.
| Important outcomes | Prevention of complications, Recurrence, Symptom severity | ||||||||
| Studies (Participants) | Outcome | Comparison | Type of evidence | Quality | Consistency | Directness | Effect size | GRADE | Comment |
| What are the effects of interventions to reduce symptoms of acute infective sore throat? | |||||||||
| 4 (553) | Symptom severity | Analgesics versus placebo | 4 | –1 | 0 | 0 | 0 | Moderate | Quality point deducted for incomplete reporting of results |
| 12 (1189) | Symptom severity | NSAIDs versus placebo | 4 | –1 | 0 | 0 | 0 | Moderate | Quality point deducted for incomplete reporting of results |
| 27 (12,835) | Symptom severity | Antibiotics versus placebo | 4 | 0 | 0 | –1 | 0 | Moderate | Directness point deducted for narrow inclusion criteria |
| 4 (734) | Symptom severity | Corticosteroids versus placebo in people receiving antibiotics | 4 | 0 | –1 | 0 | 0 | Moderate | Consistency point deducted for different results in different subgroups |
| 5 (unclear) | Recurrence | Corticosteroids versus placebo in people receiving antibiotics | 4 | –1 | –1 | 0 | 0 | Low | Quality point deducted for incomplete reporting of results. Consistency point deducted for conflicting results |
| 3 (448) | Recurrence | Probiotics versus placebo | 4 | 0 | –1 | 0 | 0 | Moderate | |
| What are the effects of interventions to prevent complications of acute infective sore throat? | |||||||||
| 16 (10,101) | Prevention of complications | Antibiotics versus placebo | 4 | 0 | 0 | 0 | +1 | High | Effect size point added for RR <0.5 |
We initially allocate 4 points to evidence from RCTs, and 2 points to evidence from observational studies. To attain the final GRADE score for a given comparison, points are deducted or added from this initial score based on preset criteria relating to the categories of quality, directness, consistency, and effect size. Quality: based on issues affecting methodological rigour (e.g., incomplete reporting of results, quasi-randomisation, sparse data [<200 people in the analysis]). Consistency: based on similarity of results across studies. Directness: based on generalisability of population or outcomes. Effect size: based on magnitude of effect as measured by statistics such as relative risk, odds ratio, or hazard ratio.
Glossary
- High-quality evidence
Further research is very unlikely to change our confidence in the estimate of effect.
- Low-quality evidence
Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
- Moderate-quality evidence
Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Acute bronchitis
Acute otitis media
Acute sinusitis
Common cold
Tonsillitis
Disclaimer
The information contained in this publication is intended for medical professionals. Categories presented in Clinical Evidence indicate a judgement about the strength of the evidence available to our contributors prior to publication and the relevant importance of benefit and harms. We rely on our contributors to confirm the accuracy of the information presented and to adhere to describe accepted practices. Readers should be aware that professionals in the field may have different opinions. Because of this and regular advances in medical research we strongly recommend that readers' independently verify specified treatments and drugs including manufacturers' guidance. Also, the categories do not indicate whether a particular treatment is generally appropriate or whether it is suitable for a particular individual. Ultimately it is the readers' responsibility to make their own professional judgements, so to appropriately advise and treat their patients. To the fullest extent permitted by law, BMJ Publishing Group Limited and its editors are not responsible for any losses, injury or damage caused to any person or property (including under contract, by negligence, products liability or otherwise) whether they be direct or indirect, special, incidental or consequential, resulting from the application of the information in this publication.
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