ICD-10-CM

H70.8: Other mastoiditis and related conditions excludes1 preauricular sinus and cyst (Q18.1) sinus, fistula, and cyst of branchial cleft (Q18.0)
H70.81: Postauricular fistula
H70.89: Other mastoiditis and related conditions

H70.8: Other mastoiditis and related conditions

excludes1
preauricular sinus and cyst (Q18.1)
sinus, fistula, and cyst of branchial cleft (Q18.0)