H70.81 Postauricular fistula

Name of the Condition

• Postauricular fistula

Summary

Postauricular fistula is a congenital or acquired abnormal tract that connects the skin behind the ear to deeper structures, often the mastoid bone or middle ear. It may present 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 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 ear. Imaging studies, such as CT scans, may be used to assess the tract’s depth or connection to underlying structures. Cultures of discharge can identify infectious organisms if present.

Treatment Options

• Observation for asymptomatic cases
• Antibiotics for infected or inflamed fistulas
• Surgical excision for persistent symptoms or recurrent infections
• Drainage of abscesses if present

Prognosis and Follow-Up

Prognosis is generally good with appropriate treatment. Asymptomatic fistulas may not require intervention, but symptomatic cases often resolve with surgery. Follow-up may involve monitoring for recurrence or infection, especially in cases managed conservatively.

Complications

• Recurrent infections or abscesses
• Chronic discharge
• Scarring or cosmetic concerns
• Rarely, extension to deeper structures (e.g., mastoiditis)

Lifestyle & Prevention

• Maintain good ear and skin hygiene
• Avoid trauma to the postauricular area
• Prompt treatment of ear infections to reduce risk
• Avoid self-manipulation of the fistula opening

When to Seek Professional Help

Seek care if the fistula becomes painful, swollen, discharges pus, or shows signs of infection. Persistent symptoms or recurrent issues warrant evaluation by a healthcare provider.

Tips for Medical Coders

Document the presence of a postauricular fistula, including any associated symptoms (e.g., discharge, infection) or interventions. Note whether the condition is congenital or acquired, as this may impact coding and documentation. Ensure specificity in describing the fistula’s location and any complications.