Peritonsillar abscess: clinical guidelines

List of Abbreviations

CT – computed tomography

ICD-10 – International Classification of Diseases 10th Revision

PTA – peritonsillar abscess

CRP – C-reactive protein

TE – bilateral tonsillectomy

Terms and Definitions

Peritonsillar abscess (PTA) is a disease characterized by purulent dissolution of the peritonsillar tissue located between the palatine tonsil pseudocapsule and the pharyngeal fascia covering the pharyngeal constrictor muscles [1;2;3].

1. Brief information on the disease or condition

1.1 Definition of the disease or condition

Peritonsillar abscess (PTA) is a disease characterized by purulent dissolution of the peritonsillar tissue located between the palatine tonsil pseudocapsule and the pharyngeal fascia covering the pharyngeal constrictor muscles [1;2].

1.2 Etiology and pathogenesis of the disease or condition (group of diseases or conditions)

The disease occurs as a result of the penetration into the peritonsillar space of microorganisms, predominantly of anaerobic type of respiration, possessing genetically determined pathogenicity factors, in the presence of favorable conditions for their colonization. The causative agents are most often group A β-hemolytic streptococcus, as well as non-spore-forming obligate anaerobic microorganisms. At the same time, representatives of co-pathogenic microorganisms belonging to the transient microbiocenosis of the oropharynx can also take part in the development of active forms of the infectious process. Peritonsillitis as a rule [3] develops against the background of changes in the immune status of the palatine tonsils, which manifests as insufficient regional immunoreactivity in the form of a decrease in T- and B-cell immunity indicators [4-8].

In most cases, a peritonsillar abscess develops as a result of purulent dissolution of the peritonsillar cellular tissue against the background of its primary inflammation, more often as a complication of acute tonsillitis, somewhat less frequently against the background of chronic tonsillitis. In this case, there is a tonsillogenic pathway of infection penetration into the peritonsillar space. An odontogenic pathway of peritonsillar tissue lesion is also possible, associated with the presence of a carious process predominantly in the posterior teeth of the mandible (second molars, wisdom teeth), as well as periostitis of the alveolar process. In a number of cases, infection is possible as a result of foreign bodies (fish bones, etc.) entering the peritonsillar tissue. In this case, the infection spreads via lymphatic vessels directly to the peritonsillar tissue, bypassing the palatine tonsils. The occurrence of peritonsillitis is facilitated by the presence of deep crypts in the palatine tonsils, penetrating the tonsil through its entire thickness and favoring the development of inflammatory processes in the peritonsillar tissue during acute tonsillitis. Frequent exacerbations of chronic tonsillitis and recurrences of acute tonsillitis are accompanied by scarring processes, in particular, in the area of the crypt orifices and palatine arches, where adhesions with the tonsil are formed. This process makes the drainage of crypts difficult, which leads to the activation of infectious agents, predominantly with an anaerobic type of metabolism, and their spread through the tonsil capsule into the peritonsillar space [9-11].

The most frequent site of infection penetration from the tonsil into the peritonsillar space is the upper pole of the tonsil. This is due to the fact that in the area of the upper pole, outside the structure of the tonsillar pseudocapsule, Weber's mucous glands are located, which become involved in inflammation during chronic tonsillitis. From here, the infection can spread directly into the peritonsillar space, which in the area of the upper pole of the tonsil contains a greater amount of loose connective tissue than in other parts. Sometimes an additional lobule is present in the supratonsillar space within the soft palate; if it is left behind during tonsillectomy, it becomes walled off by scars, which creates conditions for subsequent abscess formation [12-14].

A history of previous peritonsillitis or peritonsillar abscesses creates conditions for the recurrence of the pathological process. This is due to the fact that scar tissue developing as a result of previous peritonsillitis isolates certain areas of the peritonsillar space and contributes to the formation of latent foci of active infection in these areas [13;15;16].

Inflammatory changes in the peritonsillar tissue vary in intensity, ranging from inflammatory infiltrates to tissue necrosis. In a formed abscess, areas of peritonsillar tissue are densely infiltrated with leukocytes. Sometimes abscess formation and necrosis extend outward to such an extent that a communication is formed between the peritonsillar and parapharyngeal spaces. This occurs more frequently in external or lateral peritonsillitis [11-13].

The tissue of the tonsil itself is also involved in the process, and its parenchyma typically reveals varying degrees of exacerbation of chronic tonsillitis: infiltration of lymphoid tissue and connective tissue trabeculae, the epithelial lining of the crypts, and the surface of the tonsil with leukocytes [13-15].

Clinical and morphological forms of peritonsillitis are distinguished: edematous, infiltrative, and abscess-forming. Each of these forms may exist separately or represent only a stage or phase that subsequently transitions into another. If lymphostasis and tissue edema predominate, one can speak of the edematous form of peritonsillitis; in the infiltrative form, lymphohistiocytes and neutrophil leukocytes accumulate around blood vessels, muscle fibers, and mucous glands; upon transition to abscess formation, cellular infiltration increases even further [4;8].

When seeking medical attention, the edematous form of inflammation is diagnosed rarely, the infiltrative form in 15-20%, and the majority of patients present with the abscess-forming form of peritonsillitis, accounting for up to 80-85%. Most commonly, 4-6 days pass from the onset of the disease to the formation of an abscess, although in some cases this period is sharply reduced to a few hours. Sometimes the inflammatory process that has begun in the peritonsillar space undergoes reverse development under the influence of timely and adequate conservative treatment, and encapsulation of a small abscess is also possible [13;17-19].

1.3 Epidemiology of the Disease or Condition

A peritonsillar abscess ranks among the foremost purulent processes of the pharynx in terms of severity and is observed in people of any age, although peritonsillitis is most commonly contracted between the ages of 15 and 30 years; it is less frequent at younger and older ages. The disease affects men and women with equal frequency [4;20;21].

1.4 Features of Coding the Disease or Condition

J36 – Peritonsillar abscess

J39.0 – Retropharyngeal and parapharyngeal abscess

J39.1 – Other pharyngeal abscess

1.5 Classification of the disease or condition

Several localizations of peritonsillar abscess are distinguished:

1. Supratonsillar localization (anterosuperior), occurring in more than 70% of cases (the abscess is localized between the tonsil capsule and the upper part of the anterior palatine arch);

2. Posterior localization, occurring less frequently and accounting for about 15% of cases (the abscess is localized between the palatine tonsil and the posterior arch);

3. Inferior localization, occurring in slightly more than 5% of cases (the abscess is localized between the lower pole of the tonsil and the lateral wall of the pharynx);

4. Lateral localization, occurring in less than 5% of cases (the abscess is localized between the middle part of the tonsil and the lateral wall of the pharynx) [4;8;17].

1.6 Clinical presentation of the disease or condition

A peritonsillar abscess most frequently develops against the background of acute tonsillitis or a few days after its completion. First, vascular hyperemia and impaired vascular permeability appear in the peritonsillar tissue, edema develops, and small-cell infiltration ensues. The absorption of bacterial toxins and inflammatory reaction products causes fever, symptoms of intoxication, and changes in the blood composition. Compression of nerve trunks causes sharp pain, as well as disturbances in the central and autonomic nervous systems. The abscess is formed as a result of purulent dissolution of the infiltrate arising in the peritonsillar space. The disease begins with the onset of pain during swallowing, which gradually becomes constant and sharply intensifies when attempting to swallow saliva, radiating to the ear and teeth. Characteristic symptoms include headache, general malaise, and body temperature rising to febrile levels, with patients refusing food and drink. In the vast majority of cases, trismus of the masticatory muscles gradually arises and intensifies. Speech becomes indistinct and nasal. As a result of inflammation of the pharyngeal muscles and cervical lymphadenitis, a painful reaction occurs when turning the head; the patient holds the head tilted to one side and turns it together with the entire torso when necessary [4;8;21].

The patient's general condition becomes severe not only because of purulent inflammation in the pharynx and systemic intoxication phenomena, but also due to agonizing throat pain, sleep disturbance, inability to swallow liquids, and starvation [4;8;17].

In addition, a certain specificity of clinical symptoms is characteristic of different localizations of the peritonsillar abscess [4;8;13].

In anterosuperior or anterior peritonsillar abscess, there is a sharp bulging of the upper pole of the tonsil along with the palatine arches and soft palate toward the midline; its surface is tense and hyperemic, the uvula is displaced in the opposite direction, and the tonsil is also pushed downward and posteriorly.

Posterior peritonsillar abscess, being localized in the tissue between the posterior arch and the tonsil, can spread to the arch and the lateral wall of the pharynx. Pharyngoscopy reveals swelling in the same area. The palatine tonsil and anterior arch may be little changed, while the uvula and soft palate are usually edematous and infiltrated.

Inferior peritonsillar abscess has less pronounced pharyngoscopic signs. Only edema and infiltration of the lower part of the anterior arch are noted, however, the subjective manifestations of the disease with this localization are significant. The adjacent part of the root of the tongue is usually involved in the process, which can lead to pain upon its movement, and sometimes edema of the lingual surface of the epiglottis occurs. The spread of collateral edema to the upper section of the larynx is possible, which can lead to its stenosis.

External or lateral peritonsillar abscess is less common than other forms, but is the most severe. The process develops in the tissue filling the tonsillar fossa lateral to the tonsil, so conditions for spontaneous opening with pus breakthrough into the pharyngeal cavity are least favorable here. With this localization, edema and infiltration of the soft tissues of the neck on the affected side, torticollis, and trismus are pronounced. Inflammatory changes from the pharynx are lesser. Moderate bulging of the entire tonsil and edema of the tissues surrounding it are noted [4;8;13].

2. Diagnostics, medical indications and contraindications for diagnostic methods

Diagnostic criteria.

The diagnosis of «peritonsillar abscess» is established based on:

1. medical history data;

2. physical examination, including the physician's assessment of the patient's general condition with a thorough examination of the submandibular region and regional lymph nodes, as well as data from examinations by other specialists;

3. instrumental examination of the pharynx – pharyngoscopy;

4. laboratory test results [4;12;13].

2.1 Complaints and Anamnesis

The medical history should include indications of recent sore throats, chronic tonsillitis, previous episodes of peritonsillitis and peritonsillar abscess, prior treatment for chronic tonsillitis and its efficacy, dental caries in the oral cavity, and potential foreign bodies such as fish bones, etc. [4;13].

A patient with a peritonsillar abscess presents with pharyngeal symptoms regardless of the form of the disease:

throat pain of varying intensity, most commonly sharp and unilateral, worsening upon swallowing with possible radiation to the ear or teeth on the affected side;

foreign body sensation in the throat, nasal voice (rhinophonia),

halitosis,

neck pain when turning the head,

trismus of the masticatory muscles,

drooling

These symptoms are highly specific for this pathology. Halitosis may also occur.

In addition, systemic symptoms may be observed:

prolonged malaise, general weakness, fatigue;

decreased performance capacity;

febrile fever;

headache.

Systemic symptoms are nonspecific and always require a thorough patient evaluation and differential diagnosis.

2.2 Physical Examination

Assessment of the general condition, general physical examination, and pharyngoscopy allow acute diseases affecting the pharynx and oral cavity to be ruled out before proceeding to the diagnosis of a peritonsillar abscess.

Comments. Systemic manifestations of a peritonsillar abscess include:

- elevated body temperature (most commonly febrile fever) associated with an acute infectious disease.

- weakness, malaise, and symptoms of general intoxication associated with the systemic manifestations of an infectious disease [4;8;17].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comments: local signs of a peritonsillar abscess (which are most pronounced in anterior localization) include:

- marked hyperemia, edema, and inflammatory infiltration of the mucosa of the palatine arches, palatine tonsils, soft palate, uvula, and posterior pharyngeal wall;

- asymmetry of the soft palate and displacement of one of the tonsils;

- restricted mouth opening;

- regional lymphadenitis (depending on the localization, enlargement, induration, and tenderness upon palpation of the submandibular, retromandibular, and anterior and posterior cervical lymph nodes may occur) [4;8;17].

2.3 Laboratory Diagnostics

Laboratory diagnostic methods—such as blood and urine tests, bacteriological and mycological cultures from the tonsillar mucosa, and cytological examination of lacunar contents—are not of primary importance in detecting a peritonsillar abscess; however, a complete blood count (CBC) and serum C-reactive protein (CRP) assay help confirm the reactive nature of the bacterial inflammation. It is advisable to perform a microbiological examination of the pathological exudate obtained after surgical drainage of the abscess, isolating the pure pathogen culture and performing an antibiotic susceptibility test, in order to subsequently adjust empirical antibacterial therapy if necessary [1;7;8;10].

Comments. High leukocyte counts, a left shift in the leukocyte differential, and elevated CRP levels indicate a hyperreactive disease course with a high risk of tonsillogenic complications and require therapy adjustment, including antibacterial therapy [4].

Comments: material from the abscess cavity is collected immediately after opening the purulent cavity by inserting a sterile cotton swab or sterile 0.9% sodium chloride solution** directly into the abscess cavity and then aspirating the contents into a sterile syringe. It must be borne in mind that pus contains a large amount of proteolytic enzymes that destroy microbial structures; therefore, whenever possible, the specimen should be collected not from the purulent discharge itself, but as a wash or swab from the walls of the abscess cavity. The pathological specimen is then placed, observing asepsis rules, into a tube with transport culture medium and delivered to the bacteriological laboratory. Transport media must match the biological properties of the etiologically significant microorganisms in their composition. Special media must be used for transporting pathological material to rule out tox+ strains of C. diphtheriae. The optimal delivery time for pathological material to the bacteriological laboratory is 40 minutes. Material for molecular genetic testing is delivered to the laboratory in Eppendorf-type tubes. Special attention should be paid to minimizing the presence of active pus in the test material due to the high concentration of proteolytic enzymes capable of lysing the genetic material of microorganisms [13].

2.4 Instrumental Diagnostics

Routine pharyngoscopy performed by an otorhinolaryngologist is generally sufficient for a comprehensive assessment of the mucosal condition and oropharyngeal cytoarchitecture to identify or rule out a peritonsillar abscess.

The examination is performed under bright directed illumination using a special light source, reflected light from a head mirror, or an endoscope. Holding the tongue depressor in the left hand, the anterior 2/3 of the tongue is pressed downward without touching its root. The depressor is introduced through the right corner of the mouth [4;13].

Comments: The detection of pharyngoscopic signs is decisive in the diagnosis of a peritonsillar abscess.

Comments: In severe cases where an exact diagnosis or abscess localization cannot be established, or when it is necessary to differentiate inflammation of the paratonsillar tissue from deeper neck compartments, CT and neck ultrasound are used.

2.5 Other Procedures

Peritonsillar abscess should be differentiated from diphtheria, scarlet fever, lingual tonsil abscess, sublingual space abscess, floor of mouth phlegmon, oropharyngeal neoplasms, and pericoronitis [4;10;13].

Unilateral oropharyngeal swelling with mucosal hyperemia and edema, resembling peritonsillitis, can be observed in diphtheria and scarlet fever, which require differential diagnosis. In this case, specific epidemiological data must be considered first.

In diphtheria, the mucous membrane typically has a pale cyanotic color due to edema, with deposits present (grayish in color, extending beyond the surface of the palatine tonsils), but trismus is absent; microbiological studies isolate strains of Corynebacterium diphtheriae (tox+) [4;8].

Scarlet fever is characterized by a roseolous skin rash, a clear border between affected and intact mucosa, and a "strawberry" tongue. In inflammation and abscess formation in the lingual tonsil region, trismus and characteristic oropharyngeal changes are absent. In phlegmon of the floor of the mouth, pain, edema, and infiltration are localized in the submandibular region, tongue movements are limited, and changes in the palatine arches and tonsils are absent [4;13].

To some extent, tumor diseases—cancer, lymphosarcoma, lymphoepithelioma of the tonsil—are similar to peritonsillitis. They are characterized by slow development, absence of fever, severe sore throat, and masticatory muscle trismus, as well as tenderness upon palpation of regional lymph nodes (the latter are usually dense, slightly tender, and immobile), which helps differentiate pharyngeal tumors from peritonsillitis [4;13].

In rare cases, pharyngeal swelling may be associated with a superficial position of the carotid artery or its aneurysm. The presence of visually detectable pulsation allows for the correct diagnosis [4].

3. Treatment, including drug and non-drug therapies, diet therapy, and pain management

Treatment of patients with a peritonsillar abscess is performed by an otorhinolaryngologist in a specialized facility. The main treatment modality is surgical drainage of the abscess cavity [4;13].

3.1. Conservative management

Conservative therapy serves as an adjunct to surgical treatment methods and aims to sanitize the established focus of infection, prevent the generalization of infection, and reduce reactive inflammatory changes that have arisen in the oropharyngeal tissues [4;8;20-22].

3.1.1. General treatment

The primary role in conservative therapy is assigned to the prescription of systemic antibacterial drugs.

Comments: Antibacterial therapy should be initiated before receiving the results of bacteriological examination, and should be empirical, taking into account individual clinical manifestations.

Since microbial associations involving obligate anaerobic microorganisms are of great significance in the etiology of peritonsillar abscess, broad-spectrum antibiotics capable of acting against obligate anaerobes must be used as empirical therapy drugs [4;12;20;29]. See Table 1

Table 1. Recommended antibacterial drugs (ABDs) and treatment regimens for peritonsillar abscess [35,36,37,38]

* in pediatric practice, the dosage depends on the child's age and body weight

The course of antibacterial therapy averages 10 to 14 days. The drugs of choice are combinations of penicillins, including combinations with beta-lactamase inhibitors, which have a broad spectrum of action, including activity against obligate anaerobic pathogens. If there are problems with swallowing tableted forms of antibacterial drugs, dispersible dosage forms, suspensions, or parenteral dosage forms can be used.

In the presence of pronounced reactive manifestations from the soft tissue structures of the pharynx and neck, severe masticatory muscle trismus making the intake of tablet forms impossible, as well as a high risk of generalized complications, the prescription of parenteral 3rd generation cephalosporins is indicated, and in case of their intolerance – lincosamides (clindamycin** – ATC code: J01FF).

In pediatric practice, the use of penicillin combinations, including combinations with beta-lactamase inhibitors (ampicillin+sulbactam** – ATC code: J01CR01 and amoxicillin+clavulanic acid** – ATC code: J01CR02), is preferable; the dosage depends on the child's age and body weight.

In addition to systemic antibacterial therapy, it is necessary to prescribe systemic anti-inflammatory therapy aimed at relieving reactive symptoms, fever, and/or pain syndrome. For this purpose, nonsteroidal anti-inflammatory and antirheumatic drugs (M01A) can be used [4;8;24;27;31].

Comments: The principle of the analgesic action of NSAIDs is based on suppressing the activity of type 1 and type 2 cyclooxygenases (COX-1, COX-2) – the main enzymes that are precursors to the production of prostaglandins.

The prescription of systemic antihistamines in the treatment of peritonsillar abscess is due to the systemic effects of hyposensitization and reduces the severity of toxic-allergic reactions and systemic intoxication.

Comments: this group includes calcium preparations, ascorbic acid (vitamin C), vitamins A (A11CA). During this therapy, dynamic monitoring based on the analysis of clinical symptoms, laboratory and additional instrumental methods should be performed, and polypharmacy should be avoided.

• In case of severe general intoxication, it is recommended to administer systemic infusion (solutions affecting the water-electrolyte balance B05BB) and detoxification therapy [13].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

3.1.2. Local treatment

Comments: The purpose of local therapy is the rapid reduction of the severity of pain syndrome and other inflammatory phenomena, as well as the prevention of secondary infection of the damaged mucous membrane. Local therapy cannot replace systemic antibacterial therapy, because it does not affect the likelihood of developing "late" autoimmune complications [28-31].

When prescribing local antiseptics, one should adhere to the approved frequency of administration and age restrictions due to the certain toxicity of some of them, and take into account the possibility of allergic reactions and individual intolerance reactions [13;28-31;33].

Topical nonsteroidal anti-inflammatory drugs can be included in complex remedies as well as used as monotherapy [8;13].

3.1.3. Physiotherapy

Physiotherapy may be used after surgical intervention (incision of a peritonsillar abscess or simultaneous incision of an abscess during palatine tonsillectomy). It can be used as an independent method of general (applied to the body surface or parts thereof) and local (applied to the tonsils and regional lymph nodes) action [4;13;32].

Comments: Medications can be administered into the area of the abscess cavity or the tonsillar niches, as well as regional lymph nodes, using various physical treatment modalities.

3.2. Surgical treatment

Patients with a first-time peritonsillar abscess are indicated for incision and drainage.

Comments: for various localizations of the process and various techniques of incision of a peritonsillar abscess using different instruments, there are common principles: ensure there is no pulsation at the incision site, advancing to a depth greater than 0.5 cm into the paratonsillar tissue should be performed exclusively by blunt dissection, and the incision must be made sufficiently wide (up to 4 cm) for adequate drainage of the abscess.

The choice of the surgical incision is determined by the localization of the inflammatory process in the paratonsillar tissue. The procedure is performed under local surface anesthesia. For an anterosuperior abscess, the incision is made either through the palatoglossal arch at a typical site or at the point of greatest bulging. A posterior peritonsillar abscess is recommended to be drained through the posterior palatine arch, 0.5 cm away from its edge. When opening an inferior peritonsillar abscess, the tissue incision is made in the lower part of the palatoglossal arch. The technique of opening peritonsillar abscesses must account for the abundant blood supply of this area by branches of major arteries, therefore it is recommended to perform tissue dissection along the course of the vessels and to a shallow depth (0.5-1.0 cm), and subsequently use a hemostat, separating tissues bluntly to open the abscesses, in order to eliminate the possibility of injuring large arterial trunks. After opening the abscesses, the pharynx is rinsed with antiseptic solutions,

Subsequently, regular separation of the incision edges is performed to ensure adequate drainage until regenerative changes develop within the abscess cavity.

The radical method of treating a peritonsillar abscess is palatine tonsillectomy with simultaneous drainage of the abscess, which is performed in the presence of a history of frequent tonsillitis, recurrent peritonsillitis or peritonsillar abscess, prolonged course of the disease, inadequate drainage of the opened abscess, bleeding resulting from its incision, or the development of other tonsillogenic complications [4].

Comments: Palatine tonsillectomy with abscess incision allows not only for draining the abscess cavity, but also for removing the focus of infection in the tonsil, which is the underlying cause of the abscess formation in the peritonsillar tissue.

Palatine tonsillectomy with abscess opening is performed at any age, ranging from 3–4 up to 70 years and older. Contraindications for palatine tonsillectomy with abscess opening include terminal or extremely severe patient condition due to internal organ pathology; cerebral vascular thrombosis; diffuse meningitis.

Following infiltration anesthesia, an incision of the mucous membrane is made along the edge of the anterior palatine arch. A elevator is inserted through the incision behind the pseudo-capsule of the palatine tonsil to mobilize its upper pole. As a rule, the abscess is opened and emptied at this moment. The upper pole of the tonsil is grasped with a clamp, and the tonsil is bluntly dissected from the anterior and posterior palatine arches, descended using a broad surgical curettage spoon down to the lower pole, and adhesions are broken down if necessary. At the lower pole, the tonsil is excised using a wire snare (Baxhon snare). Upon completion of the procedure, the tonsillar fossa is carefully inspected for any potential pathological bulging (a sign of a parapharyngeal abscess).

3.3. Other treatment

None.

4. Medical Rehabilitation and Sanatorium-Resort Treatment

Rehabilitation issues in peritonsillar abscess are insufficiently developed [8].

5. Prevention and Dispensary Observation

Prevention of peritonsillar abscess involves measures to prevent the development of the disease (primary), worsening of its course (secondary), and prevention of complications (tertiary) [8;13].

Comments: Risk factors for the development of peritonsillar abscess include signs of chronic tonsillitis as well as recurrent acute tonsillitis. Preventive measures consist in eliminating risk factors, body hardening (conditioning), sanitary and educational work with the population to explain the causes of abscess formation, and timely treatment of dental and gum diseases.

6. Organization of Medical Care

Treatment is predominantly carried out by an otorhinolaryngologist in an appropriate surgical inpatient facility.

The indication for hospitalization is the need for incision of a peritonsillar abscess or palatine tonsillectomy with abscess incision.

Improvement of the condition after incision of a peritonsillar abscess or incision of an abscess during tonsillectomy is observed as early as 12–24 hours.

The indication for discharging the patient from the hospital is the completion of treatment in the otorhinolaryngology department after palatine tonsillectomy with abscess incision on the 5th–7th day postoperatively in uncomplicated cases [22]. Hospital discharge is carried out upon stable resolution of disease manifestations and the absence of any threat to the patient's life and health.

7. Additional Information

The prognosis for peritonsillar abscess, provided adequate treatment, is favorable in most cases.

The risk of purulent generalized complications increases against the background of primary and acquired immunodeficiency states (congenital immunodeficiency, immunosuppressive and cytostatic therapy, HIV infection).

Complications.

Lack of treatment or inadequate treatment of peritonsillar abscess carries a high probability of developing purulent complications, including generalized ones:

• soft tissue phlegmon of the neck

• purulent mediastinitis

• tonsillogenic sepsis

• infectious-toxic shock

Criteria for Evaluating the Quality of Medical Care

References

Appendix A1. Working Group Composition

1. N.L. Kunelskaya, MD, Professor, Member of the National Medical Association of Otorhinolaryngologists. No conflict of interest.

2. A.V. Gurov, MD, Professor, Member of the National Medical Association of Otorhinolaryngologists. No conflict of interest.

3. O.V. Karneeva, MD, Associate Professor, Member of the National Medical Association of Otorhinolaryngologists. No conflict of interest.

4. S.V. Ryazantsev, MD, Professor, Member of the National Medical Association of Otorhinolaryngologists. No conflict of interest.

5. Kh.T. Abdulkerimov, MD, Professor, Member of the National Medical Association of Otorhinolaryngologists. No conflict of interest.

6. V.I. Egorov, MD, Professor, Member of the National Medical Association of Otorhinolaryngologists. No conflict of interest.

7. A.V. Shakhov, MD, Professor, Member of the National Medical Association of Otorhinolaryngologists. No conflict of interest.

8. M.M. Polunin, MD, Professor, Member of the National Medical Association of Otorhinolaryngologists. No conflict of interest.

9. P.V. Andreev, PhD, Member of the National Medical Association of Otorhinolaryngologists. No conflict of interest.

10. S.V. Yakovlev, Doctor of Medical Sciences, Professor. No conflict of interest.

Appendix A2. Methodology for Developing Clinical Guidelines

Target audience for these clinical guidelines:

1. pediatricians;

2. city (district) pediatricians;

3. district pediatricians;

4. general practitioners (internal medicine);

5. adolescent general practitioners;

6. district general practitioners;

7. general practitioners of industrial medical districts;

8. infectious disease specialists;

9. ship doctors;

10. general practitioners (family doctors);

11. otorhinolaryngologists;

12. otorhinolaryngologist-surdologists.

Table 1. Levels of Evidence (LoE) grading scale for diagnostic methods (diagnostic interventions)

Table 2. Levels of Evidence (LoE) grading scale for prevention, treatment, and medical rehabilitation methods, including those based on natural therapeutic factors (preventive, therapeutic, and rehabilitative interventions)

Table 3. Scale for assessing the grades of recommendation (GR) for prevention, diagnostic, treatment, and medical rehabilitation methods, including those based on natural therapeutic factors (preventive, diagnostic, therapeutic, and rehabilitative interventions)

Procedure for updating clinical guidelines.

The mechanism for updating clinical guidelines provides for their systematic revision at least once every three years, as well as upon the emergence of new evidence-based medicine data on the diagnosis, treatment, prevention, and rehabilitation of specific diseases, or in the presence of justified additions/comments to previously approved clinical guidelines, but no more frequently than once every 6 months.

Appendix A3. Reference Materials

Regulatory and legal documents

1. Procedure for the provision of medical care in the specialty of "otorhinolaryngology": Order of the Ministry of Health of the Russian Federation No. 905n dated November 12, 2012, "On Approval of the Procedure for the Provision of Medical Care to the Population in the Specialty of 'Otorhinolaryngology'." Order of the Ministry of Health and Social Development of the Russian Federation No. 366n dated April 16, 2012, "On Approval of the Procedure for the Provision of Pediatric Care";

2. State Register of Medicinal Products: https://grls.rosminzdrav.ru

3. Order of the Russian Ministry of Health No. 205n dated May 2, 2023 "On Approval of the Nomenclature of Positions of Medical Workers and Pharmaceutical Workers".

4. Order of the Russian Ministry of Health No. 541n dated July 23, 2010. On Approval of the Unified Qualifications Reference Book of Positions of Managers, Specialists, and Employees, Section "Qualifying Characteristics of Positions of Healthcare Workers".

5. Federal Law No. 489-FZ dated December 25, 2018, "On Amendments to Article 40 of the Federal Law 'On Compulsory Medical Insurance in the Russian Federation' and the Federal Law 'On the Fundamentals of Public Health Protection in the Russian Federation' regarding Clinical Guidelines".

6. Order of the Russian Ministry of Health No. 103n dated February 28, 2019, "On approval of the procedure and timelines for the development of clinical guidelines, their revision, the standard template of clinical guidelines, and requirements for their structure, composition, and scientific validity of the information included in the clinical guidelines."

7. Order of the Ministry of Health of the Russian Federation No. 804n dated October 13, 2017 "On approval of the nomenclature of medical services".

8. Order of the Ministry of Health of the Russian Federation No. 1094n dated November 24, 2021 "On approval of the procedure for prescribing medicinal products, prescription forms for medicinal products, the procedure for issuing these forms, their accounting and storage, forms of prescription forms containing prescriptions for narcotic drugs or psychotropic substances, the procedure for their manufacture, distribution, registration, accounting and storage, as well as the rules for issuing prescription forms, including in the form of electronic documents"

9. "Epidemiological Surveillance of Diphtheria" Methodological Guidelines. MU 3.1.3018-12 (Approved by the Head of the Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing, Chief State Sanitary Doctor of the Russian Federation G.G. Onishchenko on June 7, 2012).

10. Resolution of the Chief State Sanitary Doctor of the Russian Federation No. 4 dated January 28, 2021 "On approval of sanitary rules and norms SanPiN 3.3686-21 "Sanitary and epidemiological requirements for the prevention of infectious diseases" (XLI. Prevention of streptococcal (group A) infection)

Clarification of notes

** – a medicinal product included in the List of Vital and Essential Drugs for medical use for 2020 (Decree of the Government of the Russian Federation No. 2406-r dated October 12, 2019)

# – off-label use – outside the indications registered in the drug's instructions is carried out by decision of the medical commission, with the permission of the Local Ethics Committee of the medical organization (if any), subject to the signed informed consent of the parents (legal representative) and the patient over 15 years of age. Requires the following procedure:

1. Justification of the need to prescribe an "off-label" medicinal product in the medical record.

2. Conduction of the medical commission of the medical organization.

3. Signing of voluntary informed consent by the patient/patient's legal representative (for minors). The consent form must be approved within the medical organization.

According to:

- cl. 5 of Federal Law No. 323-FZ of November 21, 2011 "On the Fundamentals of Protecting the Health of Citizens in the Russian Federation"

- Order of the Ministry of Health and Social Development of the Russian Federation No. 494 of August 9, 2005 "On the procedure for the use of medicinal products in patients for vital indications"

- Order No. 502n of May 5, 2012 "On Approval of the Procedure for the Establishment and Activities of the Medical Commission of a Medical Organization"

Appendix B. Physician Action Algorithms

Appendix C. Patient Information

A peritonsillar abscess is a purulent process in the paratonsillar tissue, where inflammation (paratonsillitis) first arises, and then a cavity filled with pus is formed. In most cases, it develops as a complication of tonsillitis and chronic tonsillitis and is more often localized on one side. This is one of the most common infectious and inflammatory diseases of the pharynx. Most often found in people with chronic tonsillitis and immunocompromised individuals. With late diagnosis or lack of adequate treatment, it can lead to sepsis, infectious-toxic shock, purulent mediastinitis, neck vessel hemorrhage, and other life-threatening complications.

Depending on the localization of the process, the following types of peritonsillar abscess are usually distinguished: anterior, posterior, inferior, external – in relation to the palatine tonsil. In 90% of cases, an anterosuperior location of the abscess is observed, which is associated with impaired pus drainage from the upper pole of the tonsils.

The primary cause of a peritonsillar abscess is usually a bacterial infection. Specifically, the penetration of infection from the tonsillar crypts into the surrounding peritonsillar tissues. In the overwhelming majority of cases, pyogenic Streptococcus is the cause of abscess formation. Less commonly – Staphylococcus aureus and other microorganisms.

Often, the inflammation develops as a complication of acute tonsillitis (strep throat) or chronic tonsillitis in the absence of timely and appropriate treatment. Risk factors include weakened immunity associated with inflammatory diseases, diabetes mellitus, immunodeficiency, malnutrition, smoking, and alcohol abuse. Less commonly, the disease develops against the background of dental caries and trauma to the pharyngeal tissues.

Purulent inflammation of the peritonsillar cellular tissue usually appears 3–5 days after acute tonsillitis or an exacerbation of chronic tonsillitis. When the body is weakened, this process can accelerate to as little as 24 hours.

Diagnosis of the disease begins with pharyngoscopy – examination of the pharynx. In a peritonsillar abscess, asymmetry of the fauces and bulging of the tonsil on the affected side are observed. To clarify the condition of the abscess and the extent of the inflammatory process, laryngoscopy – examination of the larynx using a laryngoscope – may be used. The patient is examined in a sitting position: the patient tilts their head back slightly, opens their mouth wide, and sticks out their tongue. This allows the otolaryngologist to examine all areas of the throat. The physician also conducts a detailed interview with the patient to identify the cause of the disease, the presence of chronic conditions, individual bodily characteristics, etc. In some cases, the patient is referred for additional examination using ultrasound and CT equipment. To prescribe treatment, certain laboratory tests may be required (complete blood count, identification of the pathogen that caused the abscess, and its antibiotic sensitivity).

Conservative treatment includes general pharmacotherapy – the prescription of antibiotics, analgesics, and other drugs – as well as local treatment – gargling the throat with antiseptic solutions and anti-inflammatory drugs.

Taking into account the clinical presentation and in cases where conservative treatment does not yield the proper effect, an abscess incision is performed to evacuate the pus. The surgery is performed under local anesthesia and takes only a few minutes: the abscess is opened, and after the pus is removed, the site of the inflammation is treated with disinfectant solutions, ensuring good outflow of contents from the abscess cavity for several days.

Surgical treatment is always combined with conservative treatment (combined, complex therapy).

In most cases, conservative treatment of a peritonsillar abscess is performed on an outpatient basis: the patient is prescribed bed rest and given instructions to carry out independently. In more severe cases and in case of recurrence, hospitalization and surgical intervention – simultaneous tonsillectomy and abscess incision – may be performed.

Appendix G. Assessment Scales, Questionnaires, and Other Evaluation Tools

Currently, there are no standardized scales or questionnaires for the management of patients with a peritonsillar abscess.