Diagnosis of Perichondritis of the Right External Ear
Perichondritis is diagnosed clinically by the hallmark finding of erythema, edema, and tenderness of the auricular cartilage with characteristic sparing of the fatty lobule, which distinguishes it from simple otitis externa or cellulitis. 1
Key Diagnostic Features
Classic Physical Examination Findings
Erythema and swelling of the auricle that spares the lobule is the pathognomonic sign that confirms perichondritis rather than otitis externa or simple skin infection. 1, 2
Painful swelling, warmth, and redness confined to the cartilaginous portions of the ear (helix, antihelix, concha) while the lobule remains uninvolved establishes the diagnosis. 2
Acute tenderness when deflecting or palpating the auricular cartilage indicates deeper perichondrial infection rather than superficial skin involvement. 2
Purulent discharge may be present in more advanced cases, particularly when abscess formation has occurred. 3
Distinguishing from Otitis Externa
Otitis externa presents with intense tragal and pinna tenderness, ear canal edema/erythema, and otorrhea, but does not spare the lobule—the entire auricle is typically tender. 4, 1
In perichondritis, the external auditory canal may show erythema and swelling of the meatus, but the defining feature remains auricular cartilage inflammation with lobular sparing. 1
If both conditions coexist (otitis externa with secondary perichondritis), you will see canal inflammation plus the characteristic lobule-sparing auricular erythema. 1
Clinical History to Elicit
Predisposing Factors
Recent trauma to the ear is the most common etiology (46% of cases), including piercings, lacerations, burns, or blunt injury. 5, 2
Diabetes mellitus or immunocompromised status significantly increases risk and may indicate malignant otitis externa with secondary perichondritis, requiring more aggressive management. 5, 3
Warm weather months are associated with higher infection rates. 2
Prior ear surgery or instrumentation can predispose to infection. 5
Symptom Progression
Onset of ear pain (otalgia) followed by progressive swelling and erythema over 2–4 days is typical. 1
Otorrhea may precede or accompany auricular inflammation if otitis externa is also present. 1
Duration of symptoms before presentation helps determine disease stage and treatment approach. 6
Physical Examination Protocol
Inspection
Assess the entire auricle for erythema, edema, and deformity, specifically noting whether the lobule is involved (cellulitis) or spared (perichondritis). 1, 7
Examine the external auditory canal for erythema, edema, debris, or otorrhea to identify concurrent otitis externa. 1
Look for fluctuance or abscess formation, which indicates need for surgical drainage. 2, 5
Inspect for cartilage necrosis or deformity, which suggests advanced disease. 7, 5
Palpation
Palpate the auricular cartilage to elicit tenderness, which is disproportionate to visual findings in early perichondritis. 2
Assess for fluctuance by gentle compression of swollen areas. 5
Examine regional lymph nodes (preauricular, postauricular, cervical) for lymphadenitis. 4
Otoscopy
Visualize the tympanic membrane to assess integrity and rule out middle ear involvement. 4
Perform pneumatic otoscopy if available to assess membrane mobility. 4
Microbiologic Considerations
Pseudomonas aeruginosa is the predominant pathogen (69% of isolates) and is associated with more advanced clinical presentation and longer hospitalization. 6, 5
Culture and sensitivity testing should be obtained from any purulent discharge or abscess drainage to guide antibiotic therapy. 5, 6
Pseudomonas infection correlates with prior trauma and requires anti-pseudomonal antibiotic coverage. 5, 6
Staging and Severity Assessment
Group A (Uncomplicated Perichondritis)
Stage 1: Erythema and edema without abscess formation—managed with antibiotics alone. 5
Stage 2: Abscess formation requiring incision and drainage—results in minor residual deformity in 50% of cases. 5
Stage 3: Extensive cartilage involvement requiring debridement—results in gross (29%) or minor (71%) residual deformity. 5
Group B (Perichondritis Secondary to Malignant Otitis Externa)
Occurs in diabetic or immunocompromised patients and requires surgical debridement via post-auricular approach plus systemic antibiotics. 5
All patients in this group develop minor residual deformities despite treatment. 5
Critical Diagnostic Pitfalls to Avoid
Failing to recognize lobular sparing leads to misdiagnosis as simple cellulitis or otitis externa, delaying appropriate anti-pseudomonal therapy. 1
Attributing symptoms solely to otitis externa when perichondritis is present results in inadequate antibiotic coverage and progression to cartilage necrosis. 1
Missing concurrent malignant otitis externa in diabetic patients, which requires more aggressive surgical and medical management. 5
Delaying diagnosis beyond 2–4 days increases risk of abscess formation and permanent deformity. 6