A18.6 Tuberculosis of (inner) (middle) ear

Name of the Condition

• Tuberculosis of (inner) (middle) ear
• ICD Code: A18.6

Summary

Tuberculosis of the inner or middle ear is a form of extrapulmonary tuberculosis where Mycobacterium tuberculosis infects the structures of the ear. This condition typically results from the spread of TB bacteria from a primary site, usually the lungs, via the bloodstream or lymphatic system. It can affect the middle ear (e.g., tympanic cavity, ossicles) or inner ear (e.g., cochlea, vestibular system), potentially leading to hearing loss, balance issues, or other otologic complications.

Causes

Tuberculosis of the inner or middle ear is caused by the dissemination of Mycobacterium tuberculosis from an existing infection, most commonly pulmonary tuberculosis. The bacteria may travel to the ear structures during active disease or reactivation of latent TB. Direct inoculation is rare but possible in certain cases.

Risk Factors

• Immunocompromised states, such as HIV/AIDS or chronic immunosuppressive therapy.
• History of untreated or inadequately treated tuberculosis.
• Close contact with individuals who have active TB.
• Living in or traveling to regions with high TB prevalence.
• Underlying conditions like diabetes, malnutrition, or chronic kidney disease.

Symptoms

• Persistent ear pain or discomfort.
• Hearing loss, which may be gradual or sudden.
• Tinnitus (ringing in the ears).
• Dizziness or vertigo (if inner ear is involved).
• Ear discharge or otorrhea.
• Systemic symptoms of TB, such as fever, night sweats, or weight loss.

Diagnosis

Diagnosis involves a combination of clinical evaluation, imaging studies (e.g., CT or MRI of the ear), and laboratory tests. A thorough history of TB exposure or infection is essential. Microbiological confirmation may require culturing ear discharge or tissue samples for Mycobacterium tuberculosis. Biopsy of affected ear tissue may be performed to identify granulomatous inflammation or acid-fast bacilli. Additional tests, such as audiometry, may assess hearing and balance function.

Treatment Options

Treatment follows standard antitubercular therapy, typically including a multi-drug regimen (e.g., isoniazid, rifampin, pyrazinamide, and ethambutol) for at least six months. Corticosteroids may be used to reduce inflammation and prevent complications like hearing loss. Surgical intervention, such as tympanoplasty or mastoidectomy, may be necessary for structural damage or persistent infection.

Prognosis and Follow-Up

Prognosis depends on early diagnosis and adherence to treatment. With appropriate therapy, many patients achieve resolution of infection and preservation of hearing or balance function. Follow-up includes regular monitoring for treatment response, hearing assessments, and screening for drug resistance. Long-term surveillance is recommended to detect recurrence or late complications.

Complications

• Permanent hearing loss or tinnitus.
• Balance disorders or vertigo.
• Chronic ear infection or otorrhea.
• Spread of infection to adjacent structures (e.g., mastoid bone).
• Resistance to antitubercular medications.

Lifestyle & Prevention

• Avoid exposure to individuals with active TB.
• Ensure completion of TB treatment if previously infected.
• Maintain good overall health to support immune function.
• Follow infection control measures in high-risk settings.

When to Seek Professional Help

Seek medical attention if you experience persistent ear pain, sudden hearing loss, dizziness, or unexplained ear discharge, especially if you have a history of TB or risk factors for the disease.

Tips for Medical Coders

Code A18.6 is used for tuberculosis involving the inner or middle ear. Documentation should specify the affected ear structure (inner or middle) and confirm the diagnosis with clinical or laboratory findings. Ensure the code is not used for other ear conditions (e.g., otitis media) without TB confirmation. Review the patient’s history for TB exposure or prior infection to support the diagnosis.