Causes of retroauricular subperiosteal abscess and fistula In the acute attack of chronic suppurative otitis media or acute fused mastoiditis, pus accumulated in the mastoid cavity flows into the retroauricular subperiosteal through the festering area of the lateral bone cortex of the mastoid, forming retroauricular subperiosteal abscess. If the abscess breaks through the periosteum and the skin behind the ear, it will form a fistula behind the ear. Clinical manifestations of retroauricular subperiosteal abscess and fistula. Acute or chronic suppurative otitis media. 2. The skin behind the ear is red, swollen and painful, which may be accompanied by systemic symptoms such as ipsilateral headache and fever. 3. Swelling behind the ear and obvious tenderness in the tympanic sinus area. The auricle is pushed forward and outward. 4. Abscess puncture can extract pus. 5. X-ray examination of mastoid shows that mastoid air cavity is blurred or typical cholesteatoma destroys the cavity. Treatment of retroauricular subperiosteal abscess and fistula. drug therapy

Systemic use of antibiotics. 2. Surgical therapy

Patients with acute mastoiditis underwent simple mastoidectomy; Combined with chronic suppurative otitis media and mastoiditis, radical mastoidectomy or modified radical mastoidectomy can be performed as appropriate.