H70.812 Postauricular fistula, left ear

Name of the Condition

• Postauricular fistula, left ear

Summary

Postauricular fistula, left ear, is a congenital or acquired abnormal tract connecting the skin behind the left ear to deeper structures, such as the mastoid bone or middle ear. It may appear as a small opening, sinus, or cyst and can be associated with chronic discharge or recurrent infections. The condition is typically benign but may require intervention if symptomatic.

Causes

Postauricular fistula is most commonly congenital, resulting from incomplete closure of the branchial cleft during embryonic development. Acquired cases may arise from chronic infections, trauma, or surgical complications. The tract forms a direct pathway between the skin and underlying structures, facilitating drainage or infection.

Risk Factors

• Congenital predisposition (family history)
• Chronic ear infections (otitis media)
• Previous ear surgery or trauma
• Immunocompromised states
• Poor hygiene or recurrent skin infections

Symptoms

• Small opening or pit behind the left ear
• Persistent or intermittent discharge
• Swelling or redness around the fistula
• Pain or tenderness
• Recurrent infections or abscess formation
• Possible hearing changes if the fistula connects to the middle ear

Diagnosis

Diagnosis is typically made through physical examination, noting the characteristic opening behind the left ear. Imaging studies, such as CT scans, may be used to assess the tract's depth and connection to underlying structures. Cultures of any discharge can help identify infectious agents.

Treatment Options

Treatment depends on symptoms and severity. Asymptomatic cases may require no intervention. Symptomatic cases may involve antibiotics for infections, incision and drainage of abscesses, or surgical excision of the fistula tract to prevent recurrence.

Prognosis and Follow-Up

Prognosis is generally good with appropriate treatment. Recurrence is possible if the tract is not fully excised. Follow-up may include monitoring for infection or complications, especially if surgery was performed.

Complications

Potential complications include chronic infection, abscess formation, or spread of infection to deeper structures. Surgical intervention carries risks such as scarring or damage to nearby tissues.

Lifestyle & Prevention

Maintain good ear hygiene and avoid trauma to the area. Prompt treatment of ear infections may reduce the risk of acquired fistula formation. Genetic counseling may be considered for congenital cases with a family history.

When to Seek Professional Help

Seek medical attention if there is persistent discharge, pain, swelling, or signs of infection (e.g., fever, redness). Recurrent infections or abscesses also warrant evaluation.

Tips for Medical Coders

Document the laterality (left ear) and whether the condition is congenital or acquired, as these details impact code assignment. Ensure clinical documentation specifies the affected ear and any associated symptoms or interventions for accurate coding.