External Otitis: Clinical Guidelines

List of Abbreviations

MEO – malignant external otitis

ICD-10 – International Classification of Diseases, 10th Revision

EO — external otitis

EAC — external auditory canal

Terms and Definitions

Otitis externa (OE) is a disease characterized by inflammatory changes in the structures of the auricle, the external auditory canal, and the epidermal layer of the tympanic membrane.

1. Brief information on the disease or condition

1.1 Definition of the disease or condition

Otitis externa (OE) is a disease characterized by inflammatory changes in the structures of the auricle, the external auditory canal, and the epidermal layer of the tympanic membrane.

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

The development of an inflammatory process in the external ear is preceded by a breach of the skin integrity, which can be caused by many factors: traumatic injury, prolonged exposure to a humid environment, skin changes associated with metabolic disorders, diabetes mellitus, dermatitis, and eczematous processes. Predisposing factors for external otitis include anatomical features of the external ear (narrow external auditory canal, presence of exostoses), wearing a hearing aid, water getting into the ears, insufficient production and altered composition of earwax, impaired local and systemic immune status, and radiation exposure.

According to literature, inflammatory diseases of the external ear are of bacterial origin in 60-98% of cases. The microbial landscape in external otitis has changed over time. While previously Staphylococcus aureus was cultured in 70-90% of clinical cases, and Pseudomonas aeruginosa was present in 10-20% of observations, recently the role of Pseudomonas aeruginosa has increased to an average of 78%, whereas Staphylococcus aureus is found in only 9-27% of cases. Less frequently, inflammatory diseases of the external ear are associated with Staphylococcus epidermidis, Streptococcus pyogenes, Streptococcus pneumoniae, Enterococcus, Escherichia coli, Proteus, Klebsiella pneumoniae, Mycoplasma pneumoniae, anaerobes, and other microorganisms. In addition to bacterial flora, pathogenic fungi play a significant role in the development of external otitis. In some cases, bacterial or bacterial-fungal associations act as the etiological factor [1, 2].

1.3 Epidemiology of the Disease or Condition

The prevalence of inflammatory diseases of the external ear ranges from 17% to 30% of all ear diseases. Factors contributing to the growth of this pathology include worsening environmental conditions, increasing flora resistance, a growing number of individuals with metabolic and immune status disorders (including allergic conditions), irrational treatment of acute inflammatory pathology, delayed consultation with an otorhinolaryngologist, and several other factors.

External otitis (EO) is a fairly common disease, but its epidemiology is still insufficiently studied, partly due to varying nomenclature for the same type of pathological process. Inflammatory diseases of the external ear occur in all countries and regions of the world, but are most frequently observed in hot and humid climates. An increase in incidence is noted during the warm season. On average, every 10th person suffers from this disease at least once in their lifetime, and 3-5% of the population suffer from the chronic form of EO. Acute EO affects approximately 0.4% of the population annually. The disease is most prevalent among people who are exposed to high humidity for prolonged periods.

EO occurs in all age groups, with the highest prevalence in older children and young adults, and a secondary increase after 65 years of age. The incidence of inflammatory diseases of the external and middle ear is approximately equal in men and women. No racial differences in the epidemiology of EO have been identified [2].

1.4 Features of Coding the Disease or Condition

H60.0 – Abscess of external ear

(Carbuncle of auricle or external auditory canal

Furuncle of auricle or external auditory canal

Abscess of auricle or external auditory canal);

H60.1 – Cellulitis of external ear

(Cellulitis: - of auricle;

- of external auditory canal);

H60.2 – Malignant external otitis;

H60.3 – Other infectious external otitis

(External otitis:

- Diffuse

- Hemorrhagic

- Swimmer's ear);

H60.4 – Cholesteatoma of external ear

(Obstructive keratosis of external ear (canal));

H60.5 – Acute external otitis, non-infectious

(Acute external otitis:

- NOS

- actinic

- chemical

- contact

- eczematous

- reactive);

H60.8 – Other external otitis

Chronic external otitis NOS;

H60.9 – External otitis, unspecified;

H61.0 – Perichondritis of external ear

(Nodular chondrodermatitis of the helix

Perichondritis:

- of external ear

- of auricle);

H61.8 – Other specified disorders of external ear

H61.9 – Disorder of external ear, unspecified;

H62.0 – External otitis in bacterial diseases classified elsewhere

(External otitis in erysipelas (A46));

H62.1 – External otitis in viral diseases classified elsewhere

(Otitis externa in:

- herpesviral [herpes simplex] infection (B00.1);

- zoster [herpes zoster] (B02.8));

H62.3 – External otitis in other infectious and parasitic diseases classified elsewhere;

H62.4 – External otitis in other diseases classified elsewhere

H62.8 – Other disorders of external ear in diseases classified elsewhere.

1.5 Classification of the disease or condition

In otorhinolaryngology, acute and chronic (duration more than 6-12 weeks) forms of EO are most commonly distinguished.

The variety of the disease is determined by the localization and nature of the inflammatory process. Nosological forms include diffuse (eczema, dermatitis, erysipelas, herpes, perichondritis, chondroperichondritis, malignant EO, and several other types) and localized EO (furuncle, abscess) [3].

1.6 Clinical presentation of the disease or condition

Examination invariably reveals skin changes in the auricle and/or external auditory canal. Changes in the tympanic membrane may also be present.

The clinical presentation of EO will vary depending on the form and stage of the disease. For instance, in localized EO (furuncle of the external auditory canal) during the infiltration stage, the leading complaint is discomfort in the ear, which worsens with manipulation in the external auditory canal, whereas upon transition to the abscess formation stage, pain becomes the primary complaint. In diffuse EO, apart from pain and ear discharge, hearing impairment may occur.

In the eczematous form of EO, the skin exhibits yellowish-pink or pink erythematous patches with mild infiltration, covered with yellowish scales. Patients complain of itching, sometimes very intense, which may precede local manifestations. Microvesicles and exudative papules may appear; upon rupture, they form punctate erosions from which exudate is released, creating areas of weeping skin with macerated and desquamated epithelium. Due to the wave-like progression of the inflammatory process, all elements (erythema, papules, vesicles, erosions, scales, crusts, excoriations) may be present simultaneously.

Herpetic lesions of the skin of the auricle and external auditory canal present with erythema, vesicles, crusts, and occasionally edema, papules, and hemorrhage. 1-2 days before the rash appears, patients experience a burning sensation, itching, and tingling at the future rash sites. A characteristic clear staging is observed. Skin inflammation resolves within 10-14 days. Under the influence of various endogenous and exogenous factors, the disease may recur. If a secondary infection supervenes, the recurrence lasts up to 3-4 weeks.

2. Diagnostics, medical indications and contraindications for diagnostic methods

Criteria for establishing the diagnosis/condition: presence of characteristic complaints and clinical presentation of the disease. Confirmation by laboratory and other methods is possible.

2.1 Complaints and Anamnesis

The main complaint in EO is discomfort and pain in the ear, in some cases aggravated by palpation and chewing. In severe inflammatory processes in the ear, pain may radiate to the eye, teeth, or pharynx. Hearing loss is typical in cases of complete obstruction of the external auditory canal by inflamed tissues or pathological discharge. In some clinical cases, itching and/or ear discharge is noted.

Systemic manifestations:

- fever (subfebrile body temperature in the vast majority of cases);

- malaise (signs of infectious toxemia).

2.2 Physical Examination

Local manifestations:

- hyperemia, edema, infiltration, lichenification, and other skin changes in the external auditory canal, and in some cases, the auricle and the superficial layer of the tympanic membrane;

- pathological discharge in the external auditory canal;

- for localized forms: presence of abscesses and infiltrates in the external acoustic meatus and other parts of the auricle;

- signs of regional lymphadenitis (enlargement, induration, and tenderness of the parotid, anterior, and posterior cervical lymph nodes) [12, 13, 14].

2.3 Laboratory Diagnostics

Comments: criteria for sampling material for microbiological examination:

- before starting antimicrobial therapy;

- under otoscopic guidance;

- material is obtained from the lumen or walls of the external acoustic meatus using a swab up to 0.3 cm in diameter, avoiding contact with the distal parts of the external acoustic meatus.

Comments: Although the incidence of malignant neoplasms among all inflammatory diseases of the external ear is less than 1%, in 90-100% of cases, malignant external otitis is associated with diabetes mellitus [34].

2.4 Instrumental Diagnostics

Comments: In uncomplicated forms of external otitis and processes not involving the middle and inner ear, conductive hearing loss may occur;

Comments: destructive changes of the temporal bone and skull base (except for malignant external otitis) are not characteristic.

In uncomplicated forms of external otitis, there is no need for diagnostic imaging [2].

2.5 Other Procedures

Comments: It is essential to perform a differential diagnosis between external otitis and its malignant form. Malignant external otitis is characterized by a number of features, which include:

• ear pain and headache on the affected side;

• edema of the walls of the external acoustic meatus;

• presence of ear discharge;

• granulations in the acoustic meatus;

• microabscesses in the external ear and skull base region;

• presence of an inflammatory focus according to scintigraphy data;

• lack of a positive response to conservative therapy for more than one week;

• presence of Pseudomonas aeruginosa according to bacteriological testing results.

Additional criteria include:

• diabetes mellitus [16, 17];

• cranial nerve neuropathies [18];

• emaciation;

• advanced age [19].

To establish the diagnosis of "malignant external otitis", the presence of all major criteria is required. If scintigraphy cannot be performed, local conservative treatment is recommended for 1-3 weeks. The absence of positive dynamics also supports the diagnosis of malignant external otitis [1, 4, 13].

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

3.1 Conservative Treatment

• All patients are recommended to eliminate predisposing factors, receive adequate pain management, and undergo regular toilet of the external acoustic meatus as standard principles of treatment for patients with bacterial diffuse external otitis [15].

GCR CLEL 5Grade of Recommendation C (Level of Evidence – 5)

Comments: The advantages of local therapy for external otitis include direct action and the creation of an optimal drug concentration in the focus of inflammation, virtually no systemic effect due to low drug absorption, and a lower risk of selecting resistant microflora strains [5, 7]. Microbial resistance and the possible presence of fungal flora require microbiological testing followed by the selection of therapy according to the spectrum of infectious agents and their susceptibility. Given the spectrum of main pathogens of acute diffuse external otitis, the drugs used must be effective against Staphylococcus aureus and Pseudomonas aeruginosa. The effectiveness of the therapy is evaluated within 48-72 hours. Persistence of symptoms requires clarification of the diagnosis and exclusion of atopic dermatitis, contact dermatitis, psoriasis, or eczema manifestations [5, 7, 11, 12, 13, 14].

• All patients with all forms of external otitis are recommended the use of various antiseptics ((benzyldimethyl[3-(myristoylamino)propyl]ammonium chloride monohydrate) D08AJ Quaternary ammonium compounds (ATC), iodine + [potassium iodide + polyvinyl alcohol] (ATC D08AG03 Iodine) and/or antimicrobial agents (fluoroquinolones, aminoglycosides, antifungal agents) [5, 9, 10, 13, 14].

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

Comments: Both single-ingredient drugs and combination products are used—combinations of various antimicrobial agents (S02AA) and antifungals, with the addition of corticosteroids and local anesthetics. According to several authors, a meta-analysis of comparative studies of various topical drugs for the treatment of acute external otitis revealed no statistically significant difference in treatment efficacy when comparing antiseptics and disinfectants with antibiotics, fluoroquinolones and aminoglycosides, or corticosteroid-antibiotic combinations versus corticosteroid monotherapy. Regardless of the active substance, during topical treatment, 65%-95% of patients achieve cure by days 7-10 from disease onset [1, 5, 7, 12, 13, 14].

Comments: Fluoroquinolones are low-toxicity drugs and do not exhibit ototoxic, hepatotoxic, nephrotoxic, mutagenic, or carcinogenic effects, nor do they adversely affect the hematopoietic system or reproductive function. This group of antimicrobial agents is characterized by a high benefit-risk ratio. The efficacy and safety of topical fluoroquinolone use in the treatment of otitis has been demonstrated in a number of randomized trials. Topical use of fluoroquinolones is more effective than other antibiotics; ofloxacin** is currently considered the gold standard in the treatment of chronic suppurative otitis media. These drugs are also effective in the treatment of diffuse external otitis.

• All patients are recommended to use topical medications in the form of ear drops for the treatment of bacterial external otitis (Tab. 1) [14, 28, 31].

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

• All patients with the eczematous form of external otitis are indicated combination therapy with corticosteroids and antimicrobial agents [37].

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

Comments: according to literature data, no statistically significant difference in treatment outcomes was found between two groups of patients, one of which received local treatment combined with systemic antibacterial therapy, while the other received topical medications and placebo.

• All patients with chondroperichondritis of the auricle are recommended systemic antibacterial drugs, as well as anti-inflammatory drugs for pain and edema relief [39].

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

Table 1 – Drops used in external otitis

3.2 Surgical Treatment

For certain forms of external otitis (furuncle of the external auditory canal at the abscess stage, purulent chondroperichondritis of the auricle, pressure ulcer of the skin of the external auditory canal, malignant (necrotizing) external otitis), surgical treatment is indicated.

3.3 Other Treatment

• It is recommended for all patients with external otitis to use physiotherapeutic methods to increase treatment efficacy [8, 9, 24-26, 35].

GCR CLEL 5Grade of Recommendation C (Level of Evidence – 5)

4. Medical Rehabilitation and Sanatorium-Resort Treatment

5. Prevention and Dispensary Observation

6. Organization of Medical Care

Treatment is predominantly outpatient; inpatient treatment is required for malignant external otitis.

Indications for hospital admission to a medical organization:

1) Necrotizing external otitis.

Indications for discharging a patient from a medical organization:

1) Subsidence of inflammation phenomena in the external auditory canal;

2) Absence of purulent-septic complications.

7. Additional Information

Criteria for Evaluating the Quality of Medical Care

References

Appendix A1. Working Group Composition

1. Shadrin G.B., Candidate of Medical Sciences, is a member of a professional association;

2. Garov E.V., Doctor of Medical Sciences, is a member of a professional association;

3. Gurov A.V., Doctor of Medical Sciences, is a member of a professional association;

4. Karneeva O.V., Doctor of Medical Sciences, Professor, is a member of a professional association;

5. Nikiforova G.N., Doctor of Medical Sciences, Professor, is a member of a professional association;

6. Anikin I.A., Doctor of Medical Sciences, Professor, is a member of a professional association;

7. Machulin A.I., Candidate of Medical Sciences, is a member of a professional association.

There is no conflict of interest.

Appendix A2. Methodology for Developing Clinical Guidelines

Target audience for these clinical guidelines:

1. general practitioners (family doctors);

2. general practitioners (internal medicine);

3. otorhinolaryngologists.

When presenting the text of the recommendations, the levels of recommendation grades (A-D) and levels of evidence (1++, 1+, 1-, 2++, 2-, 3, 4) are provided.

The used classification of the levels of evidence and recommendation grades is given in appendices P1 and P2.

Table P1 – Levels of evidence.

Table P1. Levels of Evidence (LoE) grading scale for diagnostic methods (diagnostic interventions)

Table P2. Levels of Evidence (LoE) grading scale for prevention, treatment, and rehabilitation methods (preventive, therapeutic, and rehabilitative interventions)

Table P3. Scale for assessing levels of recommendation certainty (LRC) for prevention, diagnosis, treatment, and rehabilitation methods (preventive, diagnostic, therapeutic, and rehabilitation 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

These clinical guidelines have been developed taking into account the following regulatory and legal documents:

Procedure for the provision of medical care in the profile «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 profile „otorhinolaryngology“».

Appendix B. Physician Action Algorithms

Diagram

Appendix C. Patient Information

Prevention of external otitis consists in limiting the use of cotton swabs and excessive hygiene of the auditory canal; maintaining hygiene when using earplugs, hearing aids, and headphones. Treatment is predominantly outpatient; inpatient treatment is required for malignant external otitis. When a bacterial etiology is established and pronounced general symptoms of the disease are present (fever, severe ear pain), antibiotics are prescribed depending on the pathogen and its sensitivity.

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

Not used