Introduction

Awareness of international concerns relating to the appropriateness and overprescribing of antibiotics in the dental setting led to a rigorous review of antibiotic prescribing for the management of the acute dentoalveolar abscess at Bristol Dental Hospital in 2004/5. Following a literature search of MEDLINE, EMBASE and the COCHRANE library (using the search criteria 'antibiotic' and 'dental'), minimal evidence-based usage of antibiotic prescribing was found for the management of this group of patients.1

Considering best practice, available evidence and a thorough understanding of current empirical treatment regimes, prescribing guidelines for the management of the patient with an acute dentoalveolar abscess were drawn up for use in the primary care department at the University of Bristol Dental Hospital and School.1,2,3,4

This study set out to investigate the effectiveness of a three day course of standard dose antibiotics in the management of patients with systemic symptoms related to their dentoalveolar abscess following effective drainage.

Method

Prescribing guidelines, drawn up for the Primary Care Department at the University of Bristol Dental Hospital and School, for patients with acute dentoalveolar infections and associated signs of systemic involvement were agreed within the Division on the basis of best practice and available evidence. The aim was to produce evidence-based prescribing guidelines for this group of patients (Fig. 1).1 These guidelines were implemented from 1 July 2005 and the patient outcome was audited retrospectively.

Figure 1
figure 1

Guidelines on the usage of antibiotics in the primary care setting

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The majority of patients presenting with a dentoalveolar abscess have localised swelling which can be managed by local drainage methods. A smaller number of patients present showing signs of spreading infection or with a systemic response to their infection.

For the purposes of this audit, clinical signs of pyrexia (aural temperature >36.8°C taken on the contralateral side), trismus, significant regional lymphadenopathy, gross facial swelling, closure of the eye, dysphagia, tachycardia (pulse rate >100 beats per minute) and rigors were regarded as indicators of systemic response to infection.

All adult patients found to exhibit signs of systemic involvement underwent drainage followed by removal of the cause of their infection. They were then prescribed a three day course of standard dose antibiotics as shown in Figure 1 and followed up either clinically or by telephone on completion of their antibiotic course. All patients were advised that if their symptoms had not resolved or had worsened, they should re-attend the department.

The decision to review patients by telephone was taken as a large 'failure to attend' for review was anticipated if all patients were given a formal follow-up appointment. However, for patients showing the most severe signs of systemic involvement, who were on the borderline for admission but managed as an outpatient, or for those patients who were immunocompromised, a formal follow-up appointment was made, allowing an opportunity to correlate clinical findings with the patient's perception of clinical improvement.

Immunocompromised patients included those with unstable diabetes mellitus, patients on immunosuppressant therapy, those undergoing chemotherapy or patients who had had previous radiotherapy to the head and neck.

Results

Over a 24 month period (1 July 2005 to 30 June 2007) 6,586 adult patients attended the Primary Care Department in pain. One hundred and eighty-eight patients showed signs of systemic involvement associated with a dentoalveolar abscess and were prescribed antibiotics in accordance with Figure 1 following drainage and removal of the source of infection. This resulted in an overall antiobiotic prescribing rate of 2.9%, contrasting very favourably with other studies showing much higher rates (23-74%) of antimicrobial prescribing for emergency patients.4,5,6,7

In total 22 patients were reviewed clinically; all had resolution of their systemic symptoms and the verbal:clinical correlation was 100%.

Despite repeated attempts at contact, only 129 out of the remaining 166 patients were reviewed by telephone, giving a response rate of 77.7%. Combined with those patients seen clinically a review rate of 80.3% was achieved. Overall, seven patients failed to achieve resolution of their systemic symptoms following their three day antibiotic course, giving a success rate of 95.3%. The clinical notes for these patients were re-examined in an attempt to explain the apparent failure. These records revealed that there was failure to achieve drainage in four patients and two patients failed to wait for their drainage/extractions to be carried out. The final patient re-attended after his telephone review when he was diagnosed as having a dry socket rather than an on-going infection. The socket was irrigated, dressed and healed uneventfully.

Thus, in all cases where a review was obtained and the patient had successful drainage, there was a 100% resolution in systemic symptoms.

Discussion

Antibiotics are the most widely prescribed category of drugs issued on prescription by general dental practitioners (GDPs), accounting for 7-10% of all prescriptions issued for antibiotics.8,9 A number of studies and surveys have revealed that there is widespread variation in the prescribing habits of GDPs with inconsistency in dosage, length of treatment and often inappropriate prescribing.4,5,6,10,11,12,13 A postal questionnaire by Lewis et al.14 in 1989 showed that dental practitioners estimated that only the minority of patients (approximately 5%) had an acute infection present when they issued a prescription for antibiotics. A similar picture is seen when looking at the prescribing patterns of general medical practitioners presented with oral pain.7

A number of audits have been carried out looking into the prescribing habits of general dental and general medical practitioners.15,16,17,18,19,20 Overwhelmingly these show that the antimicrobial prescribing habits are high when managing patients with acute dental pain, whether or not there is frank infection involved, and that there is wide variation in the type of antimicrobial prescribed, its dose and duration. They also highlight the lack of guidelines suggesting appropriateness in prescribing and illustrate how effective education is in reducing unnecessary prescriptions. Despite significant reductions in prescribing habits following education, it is still apparent that excessive prescriptions are being issued.16,18,19

Note has also been made of the vulnerability of general dental and medical practitioners in relation to such inappropriate prescribing in terms of potential litigation.21

A study by Kuriyama et al.15 highlights the excellent success rates in achieving stabilisation and improvement in the clinical situation following surgical drainage of the dentoalveolar infection along with rational prescribing. The definitive treatment for a patient with an acute dentoalveolar abscess is drainage followed by removal of the cause of the infection.15,22,23,24,25,26,27,28,29,30,31,32,33,34 This allows a release of pus reducing the overall number of bacteria, increasing oxygen diffusion and decreasing tissue pH.22 The predominant organisms isolated from dentoalveolar abscesses derived from the periodontal tissues are obligate anaerobes22,23,35,36,37,38,39,40,41 whereas those derived from the periapical tissues are mixed infections, with strictly anaerobic species exceeding facultative anaerobes by a factor of three to four.15,22,24,25,26,27,28,29,30,31,32,33,34,35,42,43,44,45

Following development of an abscess, the host response is to aid drainage of pus by the path of least resistance. Dependent on the anatomical site of the abscess, spread of infection may involve the muscles of mastication leading to a reduction in inter-incisal opening, presenting clinically as trismus. Alternatively the pus may spread deep to the buccinator muscle, through fascial planes, and spread beneath the skin, with the patient presenting with facial swelling. Both of these clinical signs should be regarded as signs of systemic involvement.47

As bacterial metabolites, endotoxins and exotoxins enter the bloodstream, the thermoregulatory centre in the hypothalamus responds by increasing body temperature and patients experience pyrexia.22 Pyrexia, along with regional lymphadenopathy, malaise, dysphagia, rigors and tachycardia are also signs of systemic reaction and antibiotics are needed to prevent progression to septicaemia.12,22,24,27,28,29,30,31,32,33,35,46,47,48,49 Between 2000-2005, the Office for National Statistics in England and Wales show a death rate from dentoalvolar abscess of 8-16 patients per year.50

For patients who exhibit signs of systemic infection related to their abscess, treatment with antibiotics is appropriate. The antibiotic is needed only until resolution of these systemic symptoms occurs. This usually takes 2-3 days.22,27,28,29,41,42,43,46

Resistance of micro-organisms to antibiotics is becoming increasingly important and a number of bacteria are now resistant to multiple antibiotics.51 Such is the case with methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Staphylococcus aureus (VRSA) and multiple drug-resistant Mycobacterium tuberculosis.52,53,54

Radical changes in prescribing habits and recognition of the increasing levels of resistant micro-organisms are needed to slow this ever-increasing trend.8,51,53,54,55,56,57,58,59,60,61,62 It is now clear that indiscriminate usage of antibiotics has contributed to this massive increase of resistant bacteria. As a consequence the European Centre for Disease Prevention launched the first European Antibiotics Awareness Day on 18 November 2008.63

The majority of micro-organisms isolated from dentoalveolar abscesses are Gram-negative anaerobes. Eick et al.61 demonstated that these were highly susceptible to metronidazole and clindamycin, but 22% of isolates were resistant to penicillin. Other studies have shown similar trends.60,64

The resurgence of clindamycin must also be considered. It has an excellent spectrum of activity against bacterial isolates from dentoalveloar abscesses, has superior bone penetration, stimulatory effects on the immune system and is well absorbed orally.24,42,59,65,66,67,68,69,70,71 Its historical link with pseudomembranous colitis (PMC) has been overestimated and is in fact no higher than other antimicrobials, including amoxicillin, when used in isolation.24,54,65,66,72,73,74 Caution is, however, needed in the elderly, the chronically ill, patients with a history of gastrointestinal disease, those on long-term antibiotics and those who have been hospitalised.73,75,76,77,78,79 Sandor et al22 and others have advocated its use as a primary therapeutic modality for the management of dentoalveolar abscesses.22,35,47,65,69,72,80

There is overwhelming evidence that the rise in resistant bacteria is due in part to the overprescribing of antibiotics. In order for antibiotics to continue to be effective at the time of definitive need, this rise in resistance needs to be slowed. A report by the Standing Medical Advisory Committee6 urged reduced prescribing in order to protect the future beneficial effects of antibiotics.

Historically, we as dental practitioners have been taught that antibiotics should be prescribed for 5-7 days and that patients must complete the course. It is now evident that this idea is misguided and that it actually leads to an increase in colonisation resistance.3,22 When short courses of antimicrobials are used, microbial conjugation is discouraged and transfer of resistant genes is minimised.3 When antibiotics are required, the most appropriate antibiotic should be prescribed in terms of its spectrum of activity. This optimises the therapeutic benefits of the antibiotic to the patient while minimising the risks of increasing microbial resistance. There is increasing evidence that many of the responsible oral flora are becoming resistant to penicillin59,60,61,62 and a number of studies have advocated the benefits of clindamycin as the first choice antibiotic for dentoalveolar abscess management in patients with evidence of systemic involvement.24,35,47,62,65,69,71,80

Conclusion

In the current climate of evidence-based medicine, an attempt has been made to rationalise the use of antibiotic prescribing for adult patients attending with acute dentoalveolar infections. Most can be successfully treated with surgical drainage followed by removal of the cause of the infection.15,22,23,24,25,26,27,28,29,30,31,32,33,34 For those patients who have become systemically unwell as a result of their infection, the same principles are followed along with antibiotic therapy to control and contain the systemic involvement.

This study has shown that a three day course of standard dose antibiotics, as per Figure 1, has been effective in managing these infections.

Given the annual costs to the National Health Service involved in the prescribing of antibiotics, the increasing levels of bacterial resistance, the emergence of bacterial strains resistant to multiple antimicrobial agents and the never-ending increase in litigation, extreme care should be taken when prescribing antibiotics for acute dentoalveolar infections and more emphasis should be placed on the provision of adequate drainage.