Disclaimer: The information contained within the Grand Rounds Archive is intended for use by doctors and other health care professionals. These documents were prepared by resident physicians for presentation and discussion at a conference held at Baylor College of Medicine in Houston, Texas. No guarantees are made with respect to accuracy or timeliness of this material. This material should not be used as a basis for treatment decisions, and is not a substitute for professional consultation and/or peer-reviewed medical literature.Peritonsillar Abscess Of course you have to talk about the anatomy. This is the classic Netter drawing. One can see the oral cavity, uvula, anterior pillar, posterior pillar, and tonsils. This is the area where the abscess typically forms. Here is a sagittal view - the anterior and posterior pillars, tonsils, and peritonsillar area where the abscess typically forms. Cross-section again showing anterior and posterior pillars, superior constrictive muscle, peritonsillar spaces here, retropharyngeal space, parapharyngeal space and of course the great vessels. The pathophysiology is somewhat still theorized. However, what is generally accepted now is that tonsillar disease follows one or two pathways. Either you have an acute infection that spreads to the peritonsillar space, causing peritonsillar cellulitis or you have Weber gland obstruction. Weber glands are salivary glands that sit in the tonsillar pole, the superior tonsillar pole, and their ducts excrete through the tonsillar fossa. If there is tonsillar disease, chronic tonsillitis, etc., you can have obstruction of those ducts and that can lead to stasis and as we know stasis is a setup for bacterial colonization and bacterial infection. Once again, that can lead to cellulitis. If the cellulitis goes unchecked you can have development of a peritonsillar abscess. Once the abscess is formed it can spontaneously rupture which many of these do. You can have aspiration if that occurs. Sometimes you have resolution. If the abscess continues to spread you can have spread into the retropharyngeal as well as parapharyngeal space. You can develop mediastinitis as the abscess begins to track along the carotid sheath into the mediastinum and of course with any unchecked infection you can have sepsis or death. The epidemiology reveals it is not a very common disease, about 30 per 100,000 people or 45,000 cases annually. A high proportion of cases are treated by non-head and neck doctors and specifically Emergency Room physicians. It seems to be very uncommon in the very old and the very young. There does not seem to be a sexual predilection and the annual cost is roughly 150 million dollars. This is just a CAT scan kind of showing several of the major complications you can have from peritonsillar abscess. Here is the large abscess cavity. You can see it starting to cause airway obstruction. It is spreading to the retropharyngeal space as well as the parapharyngeal space and you begin to see involvement of the great vessels and again this can track down the carotid sheath into the mediastinum causing mediastinitis, sepsis and death. The microbiology as with most abscesses is predominantly a mixed infection. You have aerobic as well as anaerobic bacteria. If you isolate the bacteria, the streptococcal species are the most common - group A or group B Strep. You also find Staph aureus, fusobacterium as well as anaerobic gram-negative rods. Many of the cultures, about 5% of the cultures, will show no growth and this is felt to be due that most patients do receive antibiotics prior to acute surgical management. In terms of the resistance of micro organisms, this is from Dr. Heron's important paper which I will go into more detail about later, but he surveyed the literature and looked at articles that talked about what percentage of microbe isolates, which ones grew out penicillin-resistant micro organisms and as you can see if you exclude this one anomaly most of the studies showed a very low rate of penicillin-resistant micro organisms with an average of around 20%. In terms of the clinical presentation, typically what you will see, the patient will complain of sore throat. It hurts when they swallow. They have low-grade fevers. They have difficulty opening their mouth. Because they are having pain when they swallow they will have increased amounts of drooling. When you look in their mouth hopefully you will see this classic picture of nice beefy red peritonsillar area edema, the uvula is deviated to the opposite side and this is indeed an abscess that is ripe for the picking. Often what you will find though is just slight asymmetry between the soft palate in terms of the level of edema and the patient will say, "you know this side really hurts. I have had a sore throat for a week but now the left side hurts more than the right" and then you look in their mouth and you see a little bit of edema. Once you suspect the diagnosis you can evaluate it. Physical examination is by far the most important way to diagnose a peritonsillar abscess. I put palpitation there specifically because you can often times palpate and you can appreciate areas of fluctuance and that can guide you towards where the abscess is and where you should direct your therapy. Needle aspiration, and I'll talk about more in great detail, but it is not only therapeutic it is also diagnostic and many people use it as a means to guide with peritonsillar abscess. Ultrasonography and CAT scan are also mentioned in the literature. Here is an example of ultrasonography. This is an external approach. Here is a normal scan, the ultrasound probe is here and the waves are coming in this direction and you can see the submandibular gland, you can see where the probe is placed. Submandibular gland, mylohyoid muscles, tongue and normal tonsillar space. In the diseased state, the probe is on the opposite side and the rays are coming in this direction, submandibular gland, tongue, and large tonsillar cavity indicating a tonsillar abscess. One paper did describe an intraoral approach and in their paper it was 90% sensitive. They compared it to CAT scan and here you can see them placing a probe intraorally. You can see the abscess cavity here on ultrasound and this is the same patient and you have the confirmation of the peritonsillar abscess. These two CAT scans are just to remind everyone that if you're getting a CAT scan to rule out a peritonsillar abscess or to look for one remember to get contrast. Without contrast you cannot differentiate between cellulitis, tumor, etc. With contrast you can see the ring enhancement which is diagnostic of an abscess. Once you've made your diagnosis, how are you are going to treat it, there are many phase of therapy, basically you have your medical therapy, intravenous fluids, antimicrobials, adjuvant corticosteroids and then you have your surgical management -abscess tonsillectomy, incision and drainage, needle aspiration and then interval tonsillectomy. Interval tonsillectomy is a strategy where you drain the abscess acutely either via incision and drainage or needle aspiration followed by the deferred decision of tonsillectomy. This chart is from Dr. Herzon’s paper again. He proposed there is no standard way to treat a peritonsillar abscess medically, so he surveyed practicing otolaryngologists to find out how did they treat peritonsillar abscess. Based on his responses, most physicians gave penicillin as an antibiotic (62%) followed by cephalosporin and clindamycin with relatively equal 20 and 21%, then amoxicillin and Augmentin, so if you look at penicillin, amoxicillin and Augmentin most of the laryngologists give one of these three medications to treat peritonsillar abscess. Some routinely admit to give IV antibiotics, about 7%, and some routinely give steroids, about 4. Abscess tonsillectomy was the first recommended. Winkler in 1911 wrote a paper as well as Barnes in 1915 in U.S.A. They both advocated abscess tonsillectomies. Holinger in 1921 gave three reasons why abscess tonsillectomy should be the standard of care. He felt that there was decreased likelihood of recurrence. You had a short recovery period and he felt that there was difficulty in completely draining an abscess with incision and drainage. The literature from the 1930s through 1970s consistently showed that abscess tonsillectomy was a safe procedure to perform. It did provide complete drainage, specifically the lower pole in cases of bilateral peritonsillar abscess, as well as, deep space abscesses, which account for as many as 20% of peritonsillar abscesses. There have been some reports or some beliefs that there is an increased risk of bleeding with abscess tonsillectomy in specifically the opposite side. I will address this further later. Incision and drainage is your next management option. As I said earlier this is described over 600 years ago and I'm sure it has been done a lot longer than that. Here again, is a nice beefy red peritonsillar abscess that is ready to be drained. You can make the incision here with an 11 blade. You take your curved hemostats and then you spread and break up all the loculations, effectively drainage the abscess. The pros are you can do it under local. It is highly efficacious and it does have an excellent safety profile. The cons would be that you do have to have some expertise and experience at draining these. There is a small failure rate and this does not prevent recurrence. There is the last thing and maybe the most important thing, is that it is very, very painful. Needle aspiration was first proposed by King in 1961. The randomized control trials by Baylor doctors, Dr. Woodson and Dr. Miller in 1985 showed that needle aspiration has a 95% success rate in that there is no difference in return to normal diet between needle aspiration and incision and drainage. Dr. Herzon whose work is probably the most important for needle aspiration, published his chronological thesis in 1995 and in it was a comprehensive study he did. He meta-analysis. He pulled his data from his own case series. He did a cost analysis. He did many things and all of which consistently showed that needle aspiration is an effective modality to treat peritonsillar abscess. As I said earlier, it can be both diagnostic and therapeutic. Non-specialists can perform it, which is an added advantage, and it does seem to be less painful than incision and drainage. Interval tonsillectomy is another treatment strategy. The only way to prevent a recurrence is with abscess tonsillectomy but the question is who would develop a recurrence. As mentioned in an earlier grand rounds, tonsillectomy fell out of favor in the late 60s and 70s, so abscess tonsillectomy as a consequence also fell out of favor and many physicians began to defer the decision of whether or not to perform a tonsillectomy in the future if the patient had a recurrence and this strategy became known as interval tonsillectomy. Again, tonsillectomy would virtually eliminate the risk of PTA but the question remains as who would benefit from interval tonsillectomy. Now that we have sort of the facts of the story, you have a lot of treatment options. You can go interval tonsillectomy, you can do abscess tonsillectomy, you can give steroids, you cannot give steroids, you can perform needle aspiration versus incision and drainage. How you balance the two between your own clinical experience and what the patient wishes and one way to do that is to use evidence-based medicine. Evidence-based medicine can provide the fulcrum to help make those management decisions. There are many tools available and one such tool is an evidence-based review. It is a systematic review of the literature. You ask a focus clinical question. For example, does mannitol reduce intracranial pressure? You perform a literature search typically with Medline and you can use MESH term, which can help provide specificity. You review the articles and you may grade the articles based on the methodology. You produce summary tables which will list the articles and their grades and then based on those summary tables and grading you make recommendations. Here is an example of the levels of evidence. This is from Sackette. There are five levels of evidence, one through five. One is individual randomized controlled trials, all or none. Meta-analysis on down the list to five, which is expert opinion. I highlighted 4 because most surgical literature is case series, which is considered a level 4. I don't want you to think just because it is level 4 that it is inherently bad. If you have 100 level four articles that say the same thing then that's good evidence. Once you have accumulated all the evidence you can grade it, so does mannitol reduce intracranial pressure if you have three level 1 studies, 2 randomized controlled trials as well as the meta-analysis that all show that it does, then that's good evidence. That's grade A evidence. If you have say 2 articles, one shows that it doesn't and one shows that it does and a Meta analysis that shows that it does reduce intracranial pressure then that's probably level B, it probably does work and then you can work your way down the list. So what did we do? We propose to do an evidence based review of peritonsillar abscess to try to answer some of these questions that kept coming up in the literature. The three questions we chose to answer were: what is the role of adjuvant steroids? What is the best means of acute surgical management and what is the recurrence rate of peritonsillar abscess? If you can determine the recurrence rate; if you can say to a patient you have a 30% chance of having another peritonsillar abscess you can predict who may benefit from tonsillectomy since that will eliminate the risk of future peritonsillar abscesses. We can find the Medline search from 1966 to 2001. We use peritonsillar abscess as a med term. We also performed a free text search and we scoured the abstract and we've limited our study to English language articles as well as experimental studies, so we excluded case studies, review articles, etc. We will review the abstracts, include the articles that just address the questions we were interested in. We graded the evidence and created summary tables and then we discussed the evidence in the end. We identified 42 articles that address the questions and in general most studies were retrospective, did not have controls and did not have adequate statistical analysis. However, we did find very good evidence. With respect to adjuvant steroids, interestingly there is no public data on the effects of adjuvant steroids in the use of peritonsillar abscess. There were 2 randomized controlled trials that looked at steroids for severe pharyngitis both of which showed that steroids reduced the amount of pain that patients have but they also were able to be discharged sooner from the emergency room, eat a normal diet faster. However, both of those studies specifically excluded patients with suspected peritonsillar abscess. In terms of acute surgical management we found five level 1 studies. I'm not going to go through all of these in detail, but this is the Baylor study here. They had 62 patients whom they randomized between needle aspiration and incision and drainage and they found that needle aspiration was 95% effective and there was no statistically significant difference between return to normal diet which was there initially. So, to review the results of the acute surgical management, as I had mentioned there were five level 1 studies. Three compared needle aspiration to incision and drainage. Overall there was no statistical difference in outcome. Roughly incision and drainage was about 94% effective and needle aspiration is 92% effective. These were small studies so there is a possibility that a type 2 error exists. A type 2 error is when you say there is no difference in outcome but really there is a difference, you just didn't have enough numbers to prove it. We conducted a power analysis to see what the likelihood of a type 2 error occurring and we found that the power analysis was 7.6% which means that there is a 92% chance that a type 2 error occurred. We then calculated, well if we wanted 80% power at P=0.5, how many patients would you need to prove that there was a difference and we found that you would need 2400 patients. The reason being is that the outcome difference is so small. Again, we are dealing with just 2 percentage points, 94 versus 92. Another way to look at this is the numbers needed to treat. The number needed to treat means how many patients will have to undergo the inferior treatment before you would have a failure that would have benefited by the superior treatment. In this case the number needed to treat is 48, so 48 patients would have to undergo needle aspiration before you would have one treatment failure that would have benefited from incision and drainage. There were two level 1 studies looking at Quinsy tonsillectomy versus interval tonsillectomy and both of these studies looked at hospital stay versus time lost from work. When they looked at the initial hospitalization rate they found that there was no difference between the two strategies. However, when they added on the second hospitalization for interval tonsillectomy, both found that there was a difference in hospital stay as well as lost time from work. So one thing to keep in mind about these two studies is that all patients were admitted to the hospital and in the current era almost no one is admitted to the hospital for a peritonsillar. So, whether or not there would be a difference in this era is hard to say. With respect to a level 4 data, most of the articles reviewed consisted of level 4 data. Earlier studies tended to emphasize that Quinsy tonsillectomy is safe and effective, later studies tended to emphasize that needle aspiration and I&D is effective. There was a cost analysis by Herzon and he calculated that needle aspiration was cheaper than incision and drainage, which was cheaper than abscess tonsillectomy. The last part of our study was the recurrence rates and indications for tonsillectomy. Again, if you can predict which patients would recur you can provide better guidance with respect to whether or not to do a tonsillectomy or just to treat acutely in lesson B. The best study would be cohort or case controlled studies where you indicate a risk factor, in this case peritonsillar abscess, follow them out over time and then calculate the relative risks and odds ratio. Most of the articles reviewed were level 4 studies. We did not find any articles that met the highest level of evidence. There were two studies however that were retrospective cohort studies. Both of them looked at whether or not tonsillitis is a risk factor for peritonsillar abscess. One study they couldn't calculate a relative risk or an odd ratio because of the study design. However, one study did calculate a P value and found that there was a statistical significant difference between the two. So if you had a history of tonsillitis you are more likely to have peritonsillar abscess. The other study did not calculate a P value. We did four of them based on their data and we found that there wasn't a statistical difference, so we found conflicting results. One study said that there was a difference and then one study that said there wasn't. The level 4 evidence which was the majority of the evidence which showed the overall the recurrence rate was about 10%. Discussion. In terms of adjuvant steroids there is no public evidence to assist you in the decision to use steroids, so in that sense we have no evidence to help you make that management decision. With respect to acute surgical management it has evolved over time from routine abscess tonsillectomy to now where incision and drainage or needle aspiration is performed acutely with a deferred decision about tonsillectomy. We found that both incision and drainage are effective and essentially equally effective. A needle aspiration may be slightly more cost-effective. With respective to Quinsy tonsillectomy, it is safe and it may be superior to interval tonsillectomy in the sense that you avoid a second hospitalization or a second recovery period. There were some studies who felt quinsy tonsillectomy was more difficult to perform and there was an increased risk of bleeding. This was addressed in the literature and most studies found that this didn't bear out. There didn't seem to be a greater blood loss. It didn't seem to be a more difficult operation. With respect to recurrence rates, we have not identified definitively based on the evidence of we reviewed however the recurrence rate does appear to be very low, about 10%, and if the decision is made for tonsillectomy one may consider Quinsy tonsillectomy since it does seem to reduce the need for a second recovery period. Pediatric peritonsillar abscess is not addressed in the literature with respect to comparing of children versus adults with the second management style. There are many studies that say that you can do needle aspiration in kids. You can do incision and drainage in kids. You can do abscess tonsillectomy in kids but there aren't studies that saythese are the major differences and this is how kids should be treated. One thing that we found interesting was that children may require general anesthesia, especially younger children. And if they do, should one perform an abscess tonsillectomy since they are already asleep?. Unfortunately there is no published evidence to guide that decision. However, I just want to remind you again that it seemed that the recurrent rate of isolated peritonsillar abscess does seem to be very low. Case Presentation: LA is 6-year-old female who presented with a several day history of increasing throat pain. It was predominately on the left side. She also complained of decreased oral intake secondary to painful swallowing, increased drooling, trismus, and low-grade fevers. She denied history of previous peritonsillar abscess or tonsillitis. Physical exam revealed left-sided soft palate swelling and redness with uvular deviation to the opposite side. She also had 2+ cryptic tonsils. A presumptive diagnosis of peritonsillar abscess was made Needle aspiration was done under local anesthesia using an 18GA spinal needle. Approximately 2cc’s of pus were aspirated. The patient was admitted for IVF and antibiotics. She recovered rapidly and was able to be discharged within 24 hours on PO medications. She was told to follow-up as needed. Bibliography: Apostolopoulos NJ, Nikolopoulos TB, Bairamis TN. Peritonsillar abscess in children. Is incision and drainage an effective management? Int J Pediatr Otorhinolaryngol 1995;31:129-135. Bonding P. Routine abscess tonsillectomy: Late results. Laryngoscope 1976;86:286-290. Bonding P. Tonsillectomy a chaud. J Laryngol Otol 1973;87:1171-1182. Brook I, Frazier EH, Thompson DH. Aerobic and anaerobic microbiology of peritonsillar abscess. Laryngoscope 1991;101:289-292. Chowdhury CR, Bricknell MC. The management of quinsy—a prospective study. J Laryngol Otol 1992;106:986-988. Fagan JJ, Wormald PJ. Quinsy tonsillectomy or interval tonsillectomy—a prospective randomised trial. S Afr Med J 1994;84:689-690. Herbild O, Bonding P. Peritonsillar abscess. Arch Otolaryngol 1981;107:540-542. Herzon FS. Permucosal needle drainage of peritonsillar abscesses. A five-year experience. Arch Otolaryngol 1984;110:104-105. Herzon FS, Aldridge JH. Peritonsillar abscess: needle aspiration. Otolaryngol Head Neck Surg 1981;89:910-911. Herzon FS, Harris P. Peritonsillar abscess: incidence, current management practices and a proposal for treatment guidelines. Laryngoscope 1995;105:1-17. Herzon FS, Nicklaus P. Pediatric peritonsillar abscesses: management guidelines. Curr Probl Pediatr 1996;26:270-278. Kieff DA, Bhattacharyya N, Siegel NS, Salman SD. Selection of antibiotics after incision and drainage of peritonsillar abscesses. Otolaryngol Head Neck Surg 1999;120:57-61. Kronenberg J, Wolf M, Leventon G. Peritonsillar abscess: recurrence rate and the indication for tonsillectomy. Am J Otolaryngol 1987;8:82-84. Lockhart R, Parker GS, Tami TA. Role of quinsy tonsillectomy in the management of peritonsillar abscess. Ann Otol Rhinol Laryngol 1991;100;569-571. Mitchelmore IJ, Prior AJ, Montgomery PQ, Tabaqchali S. Microbiological features and pathogenesis of peritonsillar abscesses. Eur J Clin Microbiol Infect Dis 1995;14:870-877. Nielsen VM, Greisen O. Peritonsillar abscess. I. Cases treated by incision and drainage: a follow-up investigation. J Laryngol Otol 1981;95:801-805. Nielsen VM, Greisen O. Peritonsillar abscess. II. Cases treated with tonsillectomy a chaud. J Laryngol Otol 1981;95:805-807. O’Brien JF, Meade JL, Falk JL. Dexamethasone as adjuvant therapy for severe acute pharyngitis. Ann Emerg Med 1993;22:212-215. Prior A, Montgomery P. Mitchelmore I, Tabagchali S. The microbiology and antibiotic treatment of peritonsillar abscesses. Clin Otolaryngol 1995;20:219-223. Sakaguchi M, Sato S, Asawa S, Taguchi K. Computed tomographic findings in peritonsillar abscess and cellulitis. J Laryngol Otol 1995;109:449-451. Schraff S, McGinn JD, Derkay CS. Peritonsillar abscess in children: a 10-year review of diagnosis and management. Int J Pediatr Otorhinolaryngol 2001;57:213-218. Snow DG, Campbell JB, Morgan DW. The management of peritonsillar sepsis by needle aspiration. Clin Otolaryngol 1991;16:245-247. Spires JR, Owens JJ, Woodson GE, Miller RH. Treatment of peritonsillar abscess. a prospective study of aspiration vs. incision and drainage. Arch Otolaryngol Head Neck Surg 1987;113:984-986. Strong EB, Woodward PJ, Johnson LP. Intraoral ultrasound evaluation of peritonsillar abscess. Laryngoscope 1995;105:779-782. Valko P. Immediate tonsillectomy in the presence of quinsy. J Otolaryngol 1983;12:259-260. Weinberg E. Brodsky L, Stanievich J, Volk M. Needle aspiration of peritonsillar abscess in children. Arch Otolaryngol Head Neck Surg 1993;119:169-172. Wolf M, Even-Chen I, Kronenberg J. Peritonsillar abscess: repeated needle aspiration versus incision and drainage. Ann Otol Rhinol Laryngol 1994;103:554-557. Wolf M, Even-Chen I, Talmi YP, Kronenberg J. The indication for tonsillectomy in children following peritonsillar abscess. Int J Pediatr Otorhinolaryngol 1995;31:43-46. Grand Rounds Archive | Department Home page BCM Public | BCM Intranet | Privacy Notices | Contact BCM | BCM Site Map | ©2001-2005 Baylor College of Medicine
|