Differential Diagnosis for Posterior Auricular Abscess in Infant
Single Most Likely Diagnosis
- Mastoiditis: This is a common complication of otitis media, especially in infants. The proximity of the mastoid air cells to the posterior auricular region and the tendency for otitis media to spread to adjacent structures make mastoiditis a likely cause of a posterior auricular abscess in an infant.
Other Likely Diagnoses
- Furuncle or Carbuncle: These are skin infections caused by Staphylococcus aureus that can occur in the posterior auricular region, especially if there is a history of trauma or shaving in this area, though less common in infants.
- Perichondritis: An infection of the cartilage and the tissue surrounding the ear, which can lead to abscess formation. It's more common in areas with cartilage, like the pinna, but can extend to the posterior auricular area.
- Cellulitis: A bacterial skin infection that can cause redness, swelling, and sometimes abscesses. While it's less specific, cellulitis in the posterior auricular region could mimic an abscess.
Do Not Miss Diagnoses
- Meningitis: Although less directly related to a posterior auricular abscess, any infection in the head and neck region of an infant warrants consideration of meningitis, especially if there are symptoms like fever, irritability, or bulging fontanelles.
- Osteomyelitis of the Skull: A bone infection that could potentially spread from an adjacent infected site, including the mastoid or the ear itself. It's rare but serious and could present with swelling or abscess formation over the affected bone.
- Lymphadenitis: Infection of the lymph nodes, which could cause swelling and potentially abscess formation in the posterior auricular region, especially if there's an underlying infection like mastoiditis or otitis media.
Rare Diagnoses
- Branchial Cleft Cyst or Abscess: Congenital anomalies that can form cysts or abscesses in the neck, including the posterior auricular region, though they are less common in this specific location.
- Dermoid Cyst: A congenital cyst that can become infected and form an abscess. While rare, dermoid cysts can occur anywhere, including the posterior auricular region.
- Actinomycosis: A rare bacterial infection that can cause abscesses and is known for forming sinus tracts. It's less common in infants and not typically the first consideration for a posterior auricular abscess.